Christian Heiss

Professor Christian Heiss

Professor of Cardiovascular Medicine
Internist, Angiologist and Cardiologist


My publications


Emilia Stegemann, Roberto Sansone, Christian Heiss (2016)Carbon Dioxide Angiography Is a Standard Technique to Supplement Iodinated Contrast Angiography and Can Be a Feasible Alternative, In: Angiology67(10)pp. 974-974 SAGE Publications
Ana Rodriguez-Mateos, Rodrigo P Feliciano, Albert Boeres, Timon Weber, Claudia Nunes dos Santos, M. Rita Ventura, Christian Heiss (2016)Cranberry (poly)phenol metabolites correlate with improvements in vascular function: A double-blind, randomized, controlled, dose-response, crossover study, In: Molecular Nutrition & Food Research60(10)pp. 2130-2140 Wiley

Scope Cranberries are rich in potentially bioactive (poly)phenols. The aim of this paper was to investigate whether cranberry juice intake can improve vascular function in healthy men in a dose‐ and time‐dependent manner, and to understand which of the circulating (poly)phenol metabolites correlate with vascular effects. Methods and results A double‐blind randomized controlled crossover trial was conducted in ten healthy males. Flow‐mediated dilation (FMD), blood pressure, pulse wave velocity and augmentation index were investigated at baseline, 1, 2, 4, 6, and 8 h post‐consumption of cranberry juices containing 409, 787, 1238, 1534, and 1910 mg of total cranberry (poly)phenols (TP), and a control drink. Plasma (poly)phenol metabolites were analyzed by UPLC‐Q‐TOF MS using authentic standards. We observed dose‐dependent increases in FMD at 1, 2, 4, 6, and 8 h with a peak at 4 h and maximal effects with juice containing 1238 mg TP. A total of 60 metabolites were quantified in plasma after cranberry consumption. Twelve (poly)phenol metabolites significantly correlated with the increases in FMD, including ferulic and caffeic acid sulfates, quercetin‐3‐O‐ß‐D‐glucuronide and a γ‐valerolactone sulfate. Conclusion (Poly)phenols in cranberry juice can improve vascular function in healthy males and this is linked to the presence of specific newly identified plasma metabolites.

Roberto Sansone, Javier I Ottaviani, Ana Rodriguez-Mateos, Yvonne Heinen, Dorina Noske, Jeremy P Spencer, Alan Crozier, Marc W Merx, Malte Kelm, Hagen Schroeter, Christian Heiss (2016)Methylxanthines enhance the effects of cocoa flavanols on cardiovascular function: randomized, double-masked controlled studies, In: The American Journal of Clinical Nutrition105(2)pp. 352-360 Oxford Academic

Background: Cocoa flavanol intake, especially that of (−)-epicatechin, has been linked to beneficial effects on human cardiovascular function. However, cocoa also contains the methylxanthines theobromine and caffeine, which may also affect vascular function. Objective: We sought to determine whether an interaction between cocoa flavanols and methylxanthines exists that influences cocoa flavanol–dependent vascular effects. Design: Test drinks that contained various amounts of cocoa flavanols (0–820 mg) and methylxanthines (0–220 mg), either together or individually, were consumed by healthy volunteers (n = 47) in 4 different clinical studies—3 with a randomized, double-masked crossover design and 1 with 4 parallel crossover studies. Vascular status was assessed by measuring flow-mediated vasodilation (FMD), brachial pulse wave velocity (bPWV), circulating angiogenic cells (CACs), and blood pressure before and 2 h after the ingestion of test drinks. Results: Although cocoa flavanol intake increased FMD 2 h after intake, the consumption of cocoa flavanols with methylxanthines resulted in a greater enhancement of FMD. Methylxanthine intake alone did not result in statistically significant changes in FMD. Cocoa flavanol ingestion alone decreased bPWV and diastolic blood pressure and increased CACs. Each of these changes was more pronounced when cocoa flavanols and methylxanthines were ingested together. It is important to note that the area under the curve of the plasma concentration of (−)-epicatechin metabolites over time was higher after the co-ingestion of cocoa flavanols and methylxanthines than after the intake of cocoa flavanols alone. Similar results were obtained when pure (−)-epicatechin and the methylxanthines theobromine and caffeine were consumed together. Conclusion: A substantial interaction between cocoa flavanols and methylxanthines exists at the level of absorption, in which the methylxanthines mediate an increased plasma concentration of (−)-epicatechin metabolites that coincides with enhanced vascular effects commonly ascribed to cocoa flavanol intake. This trial was registered at as NCT02149238.

U. B. Hendgen-Cotta, P. Luedike, M. Totzeck, M. Kropp, A. Schicho, P. Stock, C. Rammos, M. Niessen, C. Heiss, J. O. Lundberg, E. Weitzberg, M. Kelm, T. Rassaf (2012)Dietary Nitrate Supplementation Improves Revascularization in Chronic Ischemia, In: CIRCULATION126(16)pp. 1983-1992 American Heart Association

BACKGROUND: Revascularization is an adaptive repair mechanism that restores blood flow to undersupplied ischemic tissue. Nitric oxide plays an important role in this process. Whether dietary nitrate, serially reduced to nitrite by commensal bacteria in the oral cavity and subsequently to nitric oxide and other nitrogen oxides, enhances ischemia-induced remodeling of the vascular network is not known. METHODS AND RESULTS: Mice were treated with either nitrate (1 g/L sodium nitrate in drinking water) or sodium chloride (control) for 14 days. At day 7, unilateral hind-limb surgery with excision of the left femoral artery was conducted. Blood flow was determined by laser Doppler. Capillary density, myoblast apoptosis, mobilization of CD34(+)/Flk-1(+), migration of bone marrow-derived CD31(+)/CD45(-), plasma S-nitrosothiols, nitrite, and skeletal tissue cGMP levels were assessed. Enhanced green fluorescence protein transgenic mice were used for bone marrow transplantation. Dietary nitrate increased plasma S-nitrosothiols and nitrite, enhanced revascularization, increased mobilization of CD34(+)/Flk-1(+) and migration of bone marrow-derived CD31(+)/CD45(-) cells to the site of ischemia, and attenuated apoptosis of potentially regenerative myoblasts in chronically ischemic tissue. The regenerative effects of nitrate treatment were abolished by eradication of the nitrate-reducing bacteria in the oral cavity through the use of an antiseptic mouthwash. CONCLUSIONS: Long-term dietary nitrate supplementation may represent a novel nutrition-based strategy to enhance ischemia-induced revascularization.

M. M. Cortese-Krott, Z Rodriguez-Mateos, R. Sansone, G. G. C. Kuhnle, S. Thasian-Sivarajah, T. Krenz, P. Horn, C. Krisp, D. Wolters, C. Heiss, K.-D. Kroncke, N. Hogg, M. Feelisch, M. Kelm (2012)Human red blood cells at work: identification and visualization of erythrocytic eNOS activity in health and disease, In: BLOOD120(20)pp. 4229-4237 AMERICAN SOCIETY OF HEMATOLOGY

A nitric oxide synthase (NOS)-like activity has been demonstrated in human red blood cells (RBCs), but doubts about its functional significance, isoform identity and disease relevance remain. Using flow cytometry in combination with the NO-imaging probe DAF-FM we find that all blood cells form NO intracellularly, with a rank order of monocytes > neutrophils > lymphocytes > RBCs > platelets. The observation of a NO-related fluorescence within RBCs was unexpected given the abundance of the NO-scavenger oxyhemoglobin. Constitutive normoxic NO formation was abolished by NOS inhibition and intracellular NO scavenging, confirmed by laser-scanning microscopy and unequivocally validated by detection of the DAF-FM reaction product with NO using HPLC and LC-MS/MS. Employing immunoprecipitation, ESI-MS/MS-based peptide sequencing and enzymatic assay we further demonstrate that human RBCs contain an endothelial NOS (eNOS) that converts L-3H-Arginine to L-3H-Citrulline in a Ca2+/Calmodulin-dependent fashion. Moreover, in patients with coronary artery disease, red cell eNOS expression and activity are both lower than in age-matched healthy individuals and correlate with the degree of endothelial dysfunction. Thus, human RBCs constitutively produce NO under normoxic conditions via an active eNOS isoform the activity of which is compromised in patients with coronary artery disease.

Rodrigo Feliciano, Charlotte Mills, Geoffrey Istas, Christian Heiss, Ana Rodriguez-Mateos (2017)Absorption, Metabolism and Excretion of Cranberry (Poly)phenols in Humans: A Dose Response Study and Assessment of Inter-Individual Variability, In: Nutrients9(3)268 MDPI

The beneficial health effects of cranberries have been attributed to their (poly)phenol content. Recent studies have investigated the absorption, metabolism and excretion of cranberry (poly)phenols; however, little is known about whether they follow a dose response in vivo at different levels of intake. An acute double-blind randomized controlled trial in 10 healthy men with cranberry juices containing 409, 787, 1238, 1534 and 1910 mg total (poly)phenols was performed. Blood and urine were analyzed by UPLC-Q-TOF-MS. Sixty metabolites were identified in plasma and urine including cinnamic acids, dihydrocinnamic, flavonols, benzoic acids, phenylacetic acids, benzaldehydes, valerolactones, hippuric acids, catechols, and pyrogallols. Total plasma, but not excreted urinary (poly)phenol metabolites, exhibited a linear dose response (r2 = 0.74, p < 0.05), driven by caffeic acid 4-O-ß-d-glucuronide, quercetin-3-O-ß-d-glucuronide, ferulic acid 4-O-ß-d-glucuronide, 2,5-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, ferulic acid, caffeic acid 3-O-ß-d-glucuronide, sinapic acid, ferulic acid 4-O-sulfate, 3-hydroxybenzoic acid, syringic acid, vanillic acid-4-O-sulfate, (4R)-5-(3′-hydroxyphenyl)-γ-valerolactone-4′-O-sulfate, 4-methylgallic acid-3-O-sulfate, and isoferulic acid 3-O-sulfate (all r2 ≥ 0.89, p < 0.05). Inter-individual variability of the plasma metabolite concentration was broad and dependent on the metabolite. Herein, we show that specific plasma (poly)phenol metabolites are linearly related to the amount of (poly)phenols consumed in cranberry juice. The large inter-individual variation in metabolite profile may be due to variations in the gut microbiome. View Full-Text

Christine Espinola-Klein, Johannes B. Dahm, Christian Heiss, Christiane Tiefenbacher, Ralf Zahn (2017)Pocket-Leitlinie: Diagnose und Therapie der peripheren arteriellen Erkrankung (Version 2017) European Society of Cardiology

Diese Pocket-Leitlinie ist eine von der Deutschen Gesellschaft für Kardiologie – Herz- und Kreislaufforschung e.V. (DGK) übernommene Stellungnahme der European Society of Cardiology (ESC) und der European Society for Vascular Surgery (ESVS), die den gegenwärtigen Erkenntnisstand wiedergibt und Ärzten die Entscheidungsfindung zum Wohle ihrer Patienten erleichtern soll. Die Leitlinie ersetzt nicht die ärztliche Evaluation des individuellen Patienten und die Anpassung der Diagnostik und Therapie an dessen spezifische Situation. Die Pocket-Leitlinie enthält gekennzeichnete Kommentare der Autoren der Pocket- Leitlinie, die deren Einschätzung darstellen und von der Deutschen Gesellschaft für Kardiologie getragen werden. Die Erstellung dieser Leitlinie ist durch eine systematische Aufarbeitung und Zusammenstellung der besten verfügbaren wissenschaftlichen Evidenz gekennzeichnet. Das vorgeschlagene Vorgehen ergibt sich aus der wissenschaftlichen Evidenz, wobei randomisierte, kontrollierte Studien bevorzugt werden. Der Zusammenhang zwischen der jeweiligen Empfehlung und dem zugehörigen Evidenzgrad ist gekennzeichnet.

Rodrigo Feliciano, Geoffrey Istas, Christian Heiss, Ana Rodriguez-Mateos (2016)Plasma and Urinary Phenolic Profiles after Acute and Repetitive Intake of Wild Blueberry, In: Molecules21(9)1120 MDPI

Recent studies have shown that blueberries may have cardiovascular and cognitive health benefits. In this work, we investigated the profile of plasma and urine (poly)phenol metabolites after acute and daily consumption of wild blueberries for 30 days in 18 healthy men. The inter-individual variability in plasma and urinary polyphenol levels was also investigated. Blood samples were collected at baseline and 2 h post-consumption on day 1 and day 30. Twenty-four-hour urine was also collected on both days. A total of 61 phenolic metabolites were quantified in plasma at baseline, of which 43 increased after acute or chronic consumption of blueberries over one month. Benzoic and catechol derivatives represented more than 80% of the changes in phenolic profile after 2 h consumption on day 1, whereas hippuric and benzoic derivatives were the major compounds that increased at 0 and 2 h on day 30, respectively. The total (poly)phenol urinary excretion remained unchanged after 30 days of wild blueberry intake. The inter-individual variability ranged between 40%–48% in plasma and 47%–54% in urine. Taken together, our results illustrate that blueberry (poly)phenols are absorbed and extensively metabolized by phase II enzymes and by the gut microbiota, leading to a whole array of metabolites that may be responsible for the beneficial effects observed after blueberry consumption.

Roberto Sansone, Maximilian Baaken, Patrick Horn, Dominik Schuler, Ralf Westenfeld, Nicolas Amabile, Malte Kelm, Christian Heiss (2018)Endothelial microparticles and vascular parameters in subjects with and without arterial hypertension and coronary artery disease, In: Data in Brief19pp. 495-500 Elsevier

Endothelial microparticles (EMPs) are markers of endothelial injury and activation. The role of EMPs in arterial hypertension is not well understood and EMPs are increased both in arterial hypertension and coronary artery disease (CAD). The data presented here show EMPs as defined by CD31+/41−, CD62e+, and CD144+ surface markers and vascular hemodynamic parameters including office and central blood pressure, heart rate, aortic augmentation index, pulse wave velocity, flow-mediated dilation, nitroglycerin-mediated dilation, brachial artery diameter, hyperemic wall shear stress, and laser Doppler perfusion of the cutaneous microcirculation of normotensives and hypertensives with and without CAD.

Geoffrey Istas, Ken Declerck, Maria Pudenz, Katarzyna Szarc vel Szic, Veronica Lendinez-Tortajada, Montserrat Leon-Latre, Karen Heyninck, Guy Haegeman, Jose A. Casasnovas, Maria Tellez-Plaza, Clarissa Gerhauser, Christian Heiss, Ana Rodriguez-Mateos, Wim Vanden Berghe (2017)Identification of differentially methylated BRCA1 and CRISP2 DNA regions as blood surrogate markers for cardiovascular disease, In: Scientific Reports75120 Nature Publishing Group

Genome-wide Illumina InfiniumMethylation 450 K DNA methylation analysis was performed on blood samples from clinical atherosclerosis patients (n = 8) and healthy donors (n = 8) in the LVAD study (NCT02174133, NCT01799005). Multiple differentially methylated regions (DMR) could be identified in atherosclerosis patients, related to epigenetic control of cell adhesion, chemotaxis, cytoskeletal reorganisations, cell proliferation, cell death, estrogen receptor pathways and phagocytic immune responses. Furthermore, a subset of 34 DMRs related to impaired oxidative stress, DNA repair, and inflammatory pathways could be replicated in an independent cohort study of donor-matched healthy and atherosclerotic human aorta tissue (n = 15) and human carotid plaque samples (n = 19). Upon integrated network analysis, BRCA1 and CRISP2 DMRs were identified as most central disease-associated DNA methylation biomarkers. Differentially methylated BRCA1 and CRISP2 regions were verified by MassARRAY Epityper and pyrosequencing assays and could be further replicated in blood, aorta tissue and carotid plaque material of atherosclerosis patients. Moreover, methylation changes at BRCA1 and CRISP2 specific CpG sites were consistently associated with subclinical atherosclerosis measures (coronary calcium score and carotid intima media thickness) in an independent sample cohort of middle-aged men with subclinical cardiovascular disease in the Aragon Workers’ Health Study (n = 24). Altogether, BRCA1 and CRISP2 DMRs hold promise as novel blood surrogate markers for early risk stratification and CVD prevention.

C. Espinola-Klein, J. B. Dahm, C. Heiß, R. Zahn, C. Tiefenbacher (2018)Kommentar zu den Leitlinien (2017) der ESC zu peripheren arteriellen Erkrankungen, In: Der Kardiologe12(4)pp. 241-249 Springer Medizin

Die 2017 veröffentlichte „European Society of Cardiology“(ESC)-Leitlinie „Periphere Arterielle Erkrankungen“ (PAE, „peripheral arterial diseases“) umfasst Empfehlungen zur Diagnostik und Therapie von atherosklerotischen Manifestationen in peripheren Gefäßen. Es werden zu allen arteriellen Versorgungsgebieten mit Ausnahme der Aorta und Koronararterien Empfehlungen formuliert. Der folgende Kommentar bezieht sich auf die Übersetzung der Pocket-Leitlinie und ist fokussiert auf die Empfehlungen zur Sekundärprävention, zur peripheren arteriellen Verschlusskrankheit (pAVK) und zur Karotisstenose. In den Empfehlungen zur Sekundärprävention wird die Atherosklerose als Erkrankung des gesamten Gefäßsystems betrachtet. Generell wird eine konsequente Einstellung der kardiovaskulären Risikofaktoren mit absoluter Rauchkarenz, dem Einsatz von Statinen sowie einer Blutdruck- und Blutzuckerkontrolle empfohlen. Patienten mit Claudicatio intermittens sollten möglichst ein supervidiertes Gehtraining betreiben. Ein Thrombozytenaggregationshemmer sollte gegeben werden, wenn eine symptomatische pAVK vorliegt oder bei weiteren Manifestationen der Atherosklerose wie beispielsweise einer koronaren Herzerkrankung (KHK). Liegt eine starke Einschränkung im Alltag vor, wird eine Revaskularisation empfohlen. Bei Vorliegen einer Indikation zur Revaskularisation sollte bei kurzen Gefäßverschlüssen (z. B.

Emilia Stegemann, Catharina Tegtmeier, Nana Yaw Bimpong-Buta, Roberto Sansone, Mark Uhlenbruch, Andreas Richter, Berthold Stegemann, Michael Roden, Ralf Westenfeld, Malte Kelm, Christian Heiss (2015)Carbondioxide-Aided Angiography Decreases Contrast Volume and Preserves Kidney Function in Peripheral Vascular Interventions, In: Angiology67(9)pp. 875-881 SAGE Publications

Chronic kidney disease is a common comorbidity in patients with peripheral artery disease. We investigated the safety and efficacy of carbon dioxide (CO2) as supplemental contrast agent to decrease contrast volume during fluoroscopy-guided peripheral vascular procedures in routine angiological practice. We analyzed 191 consecutive interventions of the lower extremity in claudicants and critical limb ischemia (CLI) that were performed with iodinated contrast media (ICM) alone (n = 154) or with the aided or exclusive use of CO2 (n = 37). The technical success rate, total irradiation, and intervention time were not significantly different between ICM and CO2. No severe procedure-related complications occurred. The contrast volume was lower in CO2 than in ICM. Although kidney function, creatinine, and estimated glomerular filtration rate was lower in CO2 at baseline, the incidence of contrast-induced nephropathy was lower in CO2 compared to ICM. These data support CO2 as an alternative supplemental contrast agent that can be applied safely and efficiently to lower contrast volume during peripheral vascular interventions preventing kidney dysfunction even in patients with disease of the popliteal artery and below the knee and CLI.

S. Keymel, C. Heiss, P. Kleinbongard, M. Kelm, T. Lauer (2011)Impaired Red Blood Cell Deformability in Patients with Coronary Artery Disease and Diabetes Mellitus, In: HORMONE AND METABOLIC RESEARCH43(11)pp. 760-765 GEORG THIEME VERLAG

Patients with diabetes mellitus (DM) have an increased cardiovascular morbidity and mortality. There is increasing evidence that diabetes mellitus is associated with pathological hemorheological alterations, which might contribute to impaired coronary blood flow in coronary artery disease (CAD). We hypothesize that red blood cell (RBC) deformability is impaired in diabetic patients with CAD in comparison to nondiabetic patients with CAD. RBC deformability was measured in 21 patients with CAD and type 2 diabetes mellitus (CAD+DM) and 24 patients with CAD (CAD–DM). RBC deformability was measured by the Laser-assisted optical rotational cell analyzer by determining the elongation index (EI). RBC deformability was reduced in patients with CAD+DM in comparison to patients with CAD–DM (EI @ 1.12 Pa 0.236 ± 0.008 vs. 0.260 ± 0.005, p = 0.007). Inverse univariate correlations were found between the EI @ 1.12 Pa and plasma glucose concentration (r =-0.57; p

J. Klasen, D. Blondin, P. Schmitt, X. Bi, R. Sansone, H.-J. Wittsack, P. Kröpil, M. Quentin, J. Kuhlemann, F. Miese, C. Heiss, M. Kelm, G. Antoch, R.S. Lanzman (2012)Nonenhanced ECG-gated quiescent-interval single-shot MRA (QISS-MRA) of the lower extremities: Comparison with contrast-enhanced MRA, In: Clinical Radiology67(5)pp. 441-446 Elsevier Ltd

Aim To evaluate electrocardiogram (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) for nonenhanced assessment of peripheral artery occlusive disease (PAOD) using contrast-enhanced MRA (CE-MRA) as the reference standard. Materials and methods Twenty-seven patients (mean age 66.6 ± 10.8 years) with PAOD were included in the study. QISS-MRA and CE-MRA of the lower extremity were performed using a 1.5 T MR scanner. In each patient, subjective image quality and the degree of stenosis were evaluated on a four-point scale for 15 predefined arterial segments. Results Twenty-five of the 27 patients were considered for analysis. Subjective image quality of QISS-MRA was significantly lower for the distal aorta, pelvic arteries, and femoral arteries as compared to CE-MRA (p < 0.01), while no significant difference was found for other vascular segments. The degree of stenosis was overestimated with QISS-MRA in 23 of 365 (6.3%) segments and underestimated in two of 365 (0.5%) segments. As compared to CE-MRA, QISS-MRA had a high sensitivity (98.6%), specificity (96%) as well as positive and negative predictive value (88.7 and 99.6%, respectively) for the detection of significant stenosis (≥50%). Conclusion ECG-gated QISS-MRA is a promising imaging technique for reliable assessment of PAOD without the use of contrast material.

Stefanie Keymel, Yvonne Heinen, Jan Balzer, Tienush Rassaf, Malte Kelm, Thomas Lauer, Christian Heiss (2011)Characterization of macro-and microvascular function and structure in patients with type 2 diabetes mellitus, In: American Journal of Cardiovascular Research1(1)pp. pp68-75 e-Century Publishing Corporation

Objective: Diabetes mellitus (DM) leads to accelerated progression of arteriosclerosis with an increased risk of coronary events in comparison to non-diabetic patients with coronary artery disease (CAD). The precise and early detection of DM-induced vascular alterations is crucial to identify patients with high risk for cardiovascular complications. Thus, we aimed at simultaneously characterizing functional, physicomechanical, and structural vascular alterations in diabetic patients using a non-invasive approach. Research Design and Methods: In CAD patients with and without type 2 diabetes mellitus (n=50), we non-invasively measured flow-mediated dilation (FMD) of the brachial artery as a marker for endothelial function, fractional diameter changes (FDC) as a marker for physicomechanical properties, intima-media thickness (IMT) as a marker for structural properties, and forearm blood flow (FBF) as a marker for microvascular function. Results: DM was associated with reduced FMD (2.5±0.2 vs 4.8±0.4%; p≤0.001) indicating impaired macrovascular endothelial function. In parallel, reduced FDC (0.024±0.002 vs 0.034±0.004; p≤0.05) and increased IMT (0.38±0.01 vs 0.31±0.01mm; p≤0.001) indicated increased stiffness and enhanced structural alterations. Furthermore, reduced forearm blood flow during reactive hyperemia (10.7±1.0 vs. 15.3±1.4mL/min*100mL; p≤0.05) was found indicating microvascular dysfunction. Plasma glucose and HbA1c correlated with FMD (glucose: r=-0.32; HbA1c: r=-0.45), IMT (glucose: r=0.54; HbA1c: r=0.48) and FBF (glucose: r=-0.30) suggesting diabetes-specific effects on vascular properties. Conclusion: In patients with CAD, DM leads to functional and structural vascular alterations of the peripheral vasculature which are determined by the control of the disease underlining the relevance of a strict control of the DM to prevent accelerated atherosclerosis.

Martin B. Whyte, Prashanth Vas, Christian Heiss, Michael D. Feher (2020)The contribution of diabetic micro-angiopathy to adverse outcomes in COVID-19, In: Diabetes Research and Clinical Practice164108217 Elsevier

Increasing evidence points to endothelial cell dysfunction as a key pathophysiological factor in severe coronavirus disease-19 (COVID-19), manifested by platelet aggregation, microthrombi and altered vasomotor tone. This may be driven by direct endothelial cell entry by the virus, or indirectly by activated inflammatory cascade. Major risk groups identified for adverse outcomes in COVID-19 are diabetes, and those from the Black, Asian and ethnic minority (BAME) populations. Hyperglycaemia (expressed as glycated haemoglobin or mean hospital glucose) correlates with worse outcomes in COVID-19. It is not known whether hyperglycaemia is causative or is a surrogate marker - persistent hyperglycaemia is well known as an aetiological agent in microangiopathy. In this article, we propose that pre-existing endothelial dysfunction of microangiopathy, more commonly evident in diabetes and BAME groups, makes an individual vulnerable to the subsequent ‘endothelitis’ of COVID-19 infection.

Claudia Favari, Pedro Mena, Claudio Curti, Geoffrey Istas, Christian Heiss, Daniele Del Rio, Ana Rodriguez-Mateos (2020)Kinetic profile and urinary excretion of phenyl-γ-valerolactones upon consumption of cranberry: a dose–response relationship, In: Food & Function11(5)pp. 3975-3985 Royal Society of Chemistry

Cranberries are a rich source of poly(phenols), mainly monomeric and oligomeric flavan-3-ols. However, information on the appearance of their main circulating microbial metabolites, namely phenyl-γ-valerolactones and phenylvaleric acid, is lacking despite its relevance to understanding the health effects attributed to cranberries. The aim of this study was to evaluate the absorption, metabolism and urinary excretion of cranberry flavan-3-ols through the targeted analysis of phenyl-γ-valerolactones and their related phenylvaleric acids, considering also their potential as biomarkers of flavan-3-ol intake and inter-individual variability in their appearance in plasma and urine. A six-arm acute crossover, randomized, double-blinded, controlled intervention trial was performed in ten healthy males who consumed a cranberry juice drink (375, 716, 1131, 1396, 1741 mg of total flavan-3-ols) or an isocaloric control drink with one-week washout. Plasma and urine were analyzed by UHPLC-ESI-QqQ-MS/MS and 22 compounds were identified. Glucuronide and sulfate conjugates of 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone were the main circulating and excreted metabolites after cranberry juice intake, with glucuronidation appearing to be the most favorable conjugation route. These compounds reached maximum plasma concentration at about 4–6 h. Plasma and urinary concentrations of the sum of the metabolites increased in relation to the amounts of cranberry flavan-3-ols provided by the drink, showing a clear and linear dose-dependent relationship and underscoring their potential as biomarkers of flavan-3-ol intake. A high inter-individual variability in circulating and urinary metabolite levels was observed and, interestingly, some subjects seemed to display a greater efficiency in metabolizing flavan-3-ols and producing phenyl-γ-valerolactones.

Ulrich Frank, Sigrid Nikol, Jill Belch, Vinko Boc, Marianne Brodmann, Patrick H. Carpentier, Ali Chraim, Caitriona Canning, Evangelos Dimakakos, Anders Gottsäter, Christian Heiss, Lucia Mazzolai, Juraj Madaric, Dan Mircea Olinic, Zsolt Pécsvárady, Pavel Poredoš, Isabelle Quéré, Karel Roztocil, Agata Stanek, Dragan Vasic, Adriana Visonà, Jean-Claude Wautrecht, Miroslav Bulvas, Mary-Paula Colgan, Walter Dorigo, Graeme Houston, Thomas Kahan, Holger Lawall, Isak Lindstedt, Guillaume Mahe, Romeo Martini, Giles Pernod, Stanislaw Przywara, Marc Righini, Oliver Schlager, Piotr Terlecki (2019)ESVM Guideline on peripheral arterial disease, In: Vasa48(Supple)pp. 1-79 Hogrefe
Qiumei Chen, Monika Varga, Xiaoyin Wang, Daniel J. Haddad, Songtao An, Lejla Medzikovic, Ronak Derakhshandeh, Dmitry S. Kostyushev, Yan Zhang, Brian T. Clifford, Emmy Luu, Olivia M. Danforth, Ruslan Rafikov, Wenhui Gong, Stephen M. Black, Sergey V. Suchkov, Jeffrey R. Fineman, Christian Heiss, Kirstin Aschbacher, Yerem Yeghiazarians, Matthew L. Springer (2016)Overexpression of Nitric Oxide Synthase Restores Circulating Angiogenic Cell Function in Patients With Coronary Artery Disease: Implications for Autologous Cell Therapy for Myocardial Infarction, In: Journal of the American Heart Association5(1)e002257 Wiley, on behalf of American Heart Association

Background Circulating angiogenic cells (CACs) are peripheral blood cells whose functional capacity inversely correlates with cardiovascular risk and that have therapeutic benefits in animal models of cardiovascular disease. However, donor age and disease state influence the efficacy of autologous cell therapy. We sought to determine whether age or coronary artery disease (CAD) impairs the therapeutic potential of CACs for myocardial infarction (MI) and whether the use of ex vivo gene therapy to overexpress endothelial nitric oxide (NO) synthase (eNOS) overcomes these defects. Methods and Results We recruited 40 volunteers varying by sex, age (< or ≥45 years), and CAD and subjected their CACs to well‐established functional tests. Age and CAD were associated with reduced CAC intrinsic migration (but not specific response to vascular endothelial growth factor, adherence of CACs to endothelial tubes, eNOS mRNA and protein levels, and NO production. To determine how CAC function influences therapeutic potential, we injected the 2 most functional and the 2 least functional CAC isolates into mouse hearts post MI. The high‐function isolates substantially improved cardiac function, whereas the low‐function isolates led to cardiac function only slightly better than vehicle control. Transduction of the worst isolate with eNOS cDNA adenovirus increased NO production, migration, and cardiac function of post‐MI mice implanted with the CACs. Transduction of the best isolate with eNOS small interfering RNA adenovirus reduced all of these capabilities. Conclusions Age and CAD impair multiple functions of CACs and limit therapeutic potential for the treatment of MI. eNOS gene therapy in CACs from older donors or those with CAD has the potential to improve autologous cell therapy outcomes.

T. Rassaf, C. Rammos, U. B. Hendgen-Cotta, Christian Heiss, W. Kleophas, F. Dellanna, J. Floege, G. R. Hetzel, M. Kelm (2015)Vasculoprotective Effects of Dietary Cocoa Flavanols in Patients on Hemodialysis: A Double-Blind, Randomized, Placebo-Controlled Trial, In: Clinical Journal of the American Society of Nephrology11(1)pp. 108-118 American Society of Nephrology

Background and objectives: Hemodialysis (HD) per se entails vascular dysfunction in patients with ESRD. Endothelial dysfunction is a key step in atherosclerosis and is characterized by impaired flow–mediated dilation (FMD). Interventional studies have shown that cocoa flavanol (CF)–rich supplements improve vascular function. Aim of this study was to investigate the effect of flavanol–rich bioactive food ingredients on acute and chronic HD–induced vascular dysfunction in ESRD. Design, setting, participants, & measurements: We conducted a randomized, double–blind, placebo–controlled trial from 2012 to 2013. Fifty-seven participants were enrolled, ingested CF-rich beverages (900 mg CF per study day), and were compared with those ingesting CF-free placebo. This included (1) a baseline cross–over acute study to determine safety and efficacy of CF and (2) a subsequent chronic parallel group study with a 30-day follow-up period to study effects of CF on HD–mediated vascular dysfunction entailing (3) an acute substudy during HD in flavanol-naive patients and (4) an acute on chronic study during HD. Primary and secondary outcome measures included changes in FMD and hemodynamics. Results: CF ingestion was well tolerated. Acute ingestion improved FMD by 53% (3.2±0.6% to 4.8±0.9% versus placebo, 3.2±0.7% to 3.3±0.8%; P

Peijun Gong, Christian Heiss, Danuta Sampson, Qiang Wang, Zhihong Yuan, David Sampson (2020)Detection of localized pulsatile motion in cutaneous microcirculation by speckle decorrelation optical coherence tomography angiography, In: Journal of Biomedical Optics25(9)095004 Society of Photo-optical Instrumentation Engineers

Significance: Pulsatility is a vital characteristic of the cardiovascular system. Characterization of the pulsatility pattern locally in the peripheral microvasculature is currently not readily available and would provide an additional source of information which may prove important in understanding the pathophysiology of arterial stiffening, vascular ageing, and their linkage with cardiovascular disease development. Aim: We aim to confirm the suitability of speckle decorrelation optical coherence tomography angiography (OCTA) under various non-contact/contact scanning protocols for the visualization of pulsatility patterns in vessel-free tissue and in the microvasculature of peripheral human skin. Results: Results from 5 healthy subjects show distinct pulsatile patterns both in vessel-free tissue with either non-contact or contact imaging and in individual microvessels with contact imaging; respectively, likely caused by the pulsatile pressure and pulsatile blood flow. The pulse rates show good agreement with those from pulse oximetry, confirming that the pulsatile signatures reflect pulsatile hemodynamics. Conclusions: This study demonstrates the potential of speckle decorrelation OCTA for measuring localized peripheral cutaneous pulsatility and defines scanning protocols necessary to undertake such measurements. Non-contact imaging should be used for the study of pulsatility in vessel-free tissue and contact imaging with strong mechanical coupling in individual microvessels. Further studies of microcirculation based upon this method and protocols are warranted.

Francesca Leo, Thomas Krenz, Georg Wolff, Mathias Weidenbach, Christian Heiss, Malte Kelm, Brant Isakson, Miriam Margherita Cortese-Krott (2020)Assessment of tissue perfusion and vascular function in mice by scanning laser Doppler perfusion imaging, In: Biochemical Pharmacology Elsevier

Post-occlusive reactive hyperemia (PORH) is a key feature of physiological vasomotion to appropriately match the supply/demand ratio of tissues. This adaptive mechanism is severely disturbed in endothelial dysfunction with a reduced flow-mediated dilation (FMD). Reduced PORH and FMD are powerful prognostic risk factors in cardiovascular disease. While these parameters are frequently determined in human beings, comparable methods applicable to mouse models are sparse. We aimed to evaluate the applicability and accuracy of scanning laser Doppler perfusion imaging (LDPI) to measure PORH in the mouse hindlimb. Changes in mean perfusion in response to vasoactive drugs and PORH (assessed by scanning LDPI) were compared with changes in diameter and blood flow in the femoral artery, as assessed by high-resolution ultrasound. We found that the measured LDPI signal significantly correlated with changes of inflow into the femoral artery. Vasodilation induced by administration of nitroglycerine and acetylcholine increased vessel diameter, blood flow and mean perfusion, while vasoconstriction following administration of epinephrine decreased all three parameters. PORH was induced by temporal occlusion of the femoral artery with an external cuff. During occlusion, mean perfusion decreased to a condition of zero-perfusion and release of the cuff induced an immediate increase in blood flow that was followed by femoral artery dilation driving PORH/ perfusion. Surgical removal of the femoral artery decreased mean perfusion to a zero-perfusion level and fully abolished PORH. Importantly, the measurement of the PORH response by scanning LDPI is highly reproducible as determined by repeated measurements and intra/interobserver variation analysis. Last, we found that the PORH response was dependent on nitric oxide synthase and cyclooxygenase and declined with age. Thus, we here provide novel and robust non-invasive methods to serially measure tissue perfusion at baseline and during physiological and pharmacological modulation of vasomotor tone in the hindlimb of mice. The application of these LDPI scanning and ultrasound-based methods may be useful for testing the effects of drugs affecting vasomotor function or future elucidation of mechanisms leading to vasomotor dysfunction in mice in vivo.

Rodrigo P Feliciano, Sarah Pritzel, Christian Heiss, Ana Rodriguez-Mateos (2015)Flavonoid intake and cardiovascular disease risk, In: Current Opinion in Food Science2pp. 92-99 Elsevier

Emerging evidence from epidemiological and randomized controlled trials (RCTs) support protective effects of foods and dietary supplements rich in flavonoids against cardiovascular disease (CVD). Epidemiological studies provide valuable information in this field but the estimation of flavonoid intake is still prone to bias due to limitations of food-frequency-questionnaires and lack of biomarkers. Advancements in mass spectrometry led to more accurate flavonoid quantification in foods and biological fluids and development of comprehensive metabolomic databases. Current research is still struggling with the establishment and validation of new biomarkers of flavonoid intake. Efforts to create adequate standardized materials and well-matched controls used in RCTs have also improved data robustness. However, the relationship between flavonoid intake and CVD is still not fully established.

Tienush Rassaf, Christian Heiss, Sarah Mangold, Thorsten Leyendecker, Eva S. Kehmeier, Malte Kelm, Thomas Lauer (2010)Vascular Formation of Nitrite After Exercise Is Abolished in Patients With Cardiovascular Risk Factors and Coronary Artery Disease, In: Journal of the American College of Cardiology55(14)pp. 1502-1503 Elsevier
Anna Eckers, Sascha Jakob, Christian Heiss, Thomas Haarmann-Stemmann, Christine Goy, Vanessa Brinkmann, Miriam M. Cortese-Krott, Roberto Sansone, Charlotte Esser, Niloofar Ale-Agha, Joachim Altschmied, Natascia Ventura, Judith Haendeler (2016)The aryl hydrocarbon receptor promotes aging phenotypes across species, In: Scientific Reports6(1)19618 Nature Publishing Group

The ubiquitously expressed aryl hydrocarbon receptor (AhR) induces drug metabolizing enzymes as well as regulators of cell growth, differentiation and apoptosis. Certain AhR ligands promote atherosclerosis, an age-associated vascular disease. Therefore, we investigated the role of AhR in vascular functionality and aging. We report a lower pulse wave velocity in young and old AhR-deficient mice, indicative of enhanced vessel elasticity. Moreover, endothelial nitric oxide synthase (eNOS) showed increased activity in the aortas of these animals, which was reflected in increased NO production. Ex vivo, AhR activation reduced the migratory capacity of primary human endothelial cells. AhR overexpression as well as treatment with a receptor ligand, impaired eNOS activation and reduced S-NO content. All three are signs of endothelial dysfunction. Furthermore, AhR expression in blood cells of healthy human volunteers positively correlated with vessel stiffness. In the aging model Caenorhabditis elegans, AhR-deficiency resulted in increased mean life span, motility, pharynx pumping and heat shock resistance, suggesting healthier aging. Thus, AhR seems to have a negative impact on vascular and organismal aging. Finally, our data from human subjects suggest that AhR expression levels could serve as an additional, new predictor of vessel aging.

Christian Meyer, Christian Heiss, Christine Drexhage, Eva S. Kehmeier, Jan Balzer, Anja Mühlfeld, Marc W. Merx, Thomas Lauer, Harald Kühl, Jürgen Floege, Malte Kelm, Tienush Rassaf (2010)Hemodialysis-Induced Release of Hemoglobin Limits Nitric Oxide Bioavailability and Impairs Vascular Function, In: Journal of the American College of Cardiology55(5)pp. 454-459 Elsevier

Objectives This study sought to characterize the impact of hemodialysis (HD)-induced release of hemoglobin on the bioavailability of nitric oxide (NO) and endothelial function. Background Patients on chronic HD suffer from endothelial dysfunction and a massively increased risk for cardiovascular events. Although dialysis-dependent and -independent factors are discussed, the exact mechanisms are not fully understood. Methods In 14 HD patients (56 ± 15 years of age), endothelial function was determined by measuring flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound before and after treatment. The NO consumption activity of plasma isolated from patients before and after hemodialysis was studied with an NO-sensitive electrode. Results HD impaired FMD (3.5 ± 2.6% to 1.7 ± 1.4%, p = 0.04) without affecting brachial artery diameter (4.7 ± 0.6 mm vs. 4.4 ± 0.9 mm, p = 0.27). This was accompanied by an increase in cell-free plasma hemoglobin (196 ± 43 mg/l to 285 ± 109 mg/l, p = 0.01), which led to a decrease in the bioavailability of free NO by more than 70%. Oxidation of the released plasma ferrous hemoglobin prevented the consumption of NO. The amount of decompartmentalized hemoglobin after HD correlated inversely with the change in FMD (r = −0.65, p = 0.041). Conclusions Our data support a role of HD-induced release of hemoglobin in the pathogenesis of endothelial dysfunction in patients with end-stage renal disease. Approaches that oxidize free plasma hemoglobin may restore NO bioavailability and may have potential beneficial effects on vascular function. (Influence of Hemodialysis on Endothel-Depending Dilatation of Peripheral Arteries; NCT00764192)

Kranthi Pinnamaneni, Richard E. Sievers, Rikki Sharma, Amanda M. Selchau, Gustavo Gutierrez, Eric J. Nordsieck, Robert Su, Songtao An, Qiumei Chen, Xiaoyin Wang, Ronak Derakhshandeh, Kirstin Aschbacher, Christian Heiss, Stanton A. Glantz, Suzaynn F. Schick, Matthew L. Springer (2013)Brief Exposure to Secondhand Smoke Reversibly Impairs Endothelial Vasodilatory Function, In: Nicotine & Tobacco Research16(5)pp. 584-590 Oxford Journals

Introduction: We sought to determine the effects of brief exposures to low concentrations of tobacco secondhand smoke (SHS) on arterial flow-mediated dilation (FMD, a nitric oxide-dependent measure of vascular endothelial function), in a controlled animal model never before exposed to smoke. In humans, SHS exposure for 30min impairs FMD. It is important to gain a better understanding of the acute effects of exposure to SHS at low concentrations and for brief periods of time. Methods: We measured changes in FMD in rats exposed to a range of real-world levels of SHS for durations of 30min, 10min, 1min, and 4 breaths (roughly 15 s). Results: We observed a dose-response relationship between SHS particle concentration over 30min and post-exposure impairment of FMD, which was linear through the range typically encountered in smoky restaurants and then saturated at higher concentrations. One min of exposure to SHS at moderate concentrations was sufficient to impair FMD. Conclusions: Brief SHS exposure at real-world levels reversibly impairs FMD. Even 1min of SHS exposure can cause reduction of endothelial function.

Christian Heiss, Ioakim Spyridopoulos, Judith Haendeler (2017)Interventions to slow cardiovascular aging: Dietary restriction, drugs and novel molecules, In: Experimental Gerontology109pp. 108-118 Elsevier

Cardiovascular aging is a highly dynamic process. Despite the fact that cardiovascular function and structure change with age, they can still be modulated even in aged humans. The most prominent approaches to improve age-dependent vascular changes include dietary restriction and pharmacologic agents interacting with signaling pathways implicated in this context. These include inhibition of TOR, glycolysis, and GH/IGF-1, activation of sirtuins, and AMPK, as well as modulators of inflammation, epigenetic pathways, and telomeres. Promising nutritional approaches include Mediterranean diet and novel dietary bioactives including flavanols, anthocyanins, and lignins. Many plant bioactives improve cardiovascular parameters implied in vascular healthy aging including endothelial function, arterial stiffness, blood pressure, cholesterol, and glycemic control. However, the mechanism of action of most bioactives is not established and it remains to be elucidated whether they act as dietary restriction mimetics or via other modes of action. Even more importantly, whether these interventions can slow or even reverses components of cardiovascular aging itself and can increase healthspan or longevity in humans needs to be determined.

T Mengden, M Hausberg, Christian Heiss, A Mitchell, U Nixdorff, C Ott, A Schmidt-Trucksäss, S Wassertheurer (2016)Arterielle Gefäßsteifigkeit – Ursachen und Konsequenzen (Arterial stiffness – Causes and consequences), In: Der Kardiologe10(1)pp. 38-46 Springer Berlin Heidelberg

Measurement of the aortic pulse wave velocity (aPWV) is a direct measure for the arterial stiffness of the aorta and is 4–9 m/s in normotensive healthy individuals, depending on age. In comparison to classical cardiovascular parameters, the aPWV has an additive predictive value for cardiovascular events. An increase in the aPWV of 1 m/s is associated with an increase in cardiovascular risk of up to 15 %. The differentiation between calcified arteriosclerosis and non-calcified atherosclerosis is clinically important. The presence of atherosclerosis, such as coronary heart disease, cannot be directly deduced from a finding of increased vascular stiffness. The gold standard for measurement of aortic stiffness is considered to be the PWV between the carotid and femoral arteries. Until the results of further studies are available, an aPWV above 10 m/s should be considered as pathological in normotensive individuals. Many of the instruments available on the market for measurement of vascular stiffness still show an insufficient standardization with respect to the measurement method and measurement accuracy. A standardized validation against invasive or non-invasive gold standards should be available, independent of the manufacturer and an additive predictive value confirmed by epidemiological and prognostic studies. The most important therapeutic aim of the treatment of arterial vascular stiffness is a normalization of blood pressure values according to the current European Society of Hypertension (ESH) guidelines. Based on long-term influences on vascular remodeling, according to the current state of the art blockers of the renin-angiotensin-aldosterone system are assumed to be more suitable to achieve extended effects on vascular stiffness other than pure blood pressure effects. Whether antihypertensive therapy with the target parameter of vascular stiffness also has a positive influence on concrete cardiovascular endpoints, is the subject of currently running studies.

Christian Heiss (2016)Electronic cigarettes increase EPCs, In: Atherosclerosis255pp. 119-121 Elsevier
Dirk Blondin, Christian Heiss (2013)Vascular Imaging Using MR Angiography. (MR-Angiografie zur Gefäßdiagnostik)., In: Aktuelle Kardiologie2(2)pp. 112-118

Contrast enhanced magnetic resonance angiography (MRA) with gadolinium containing contrast media has evolved to a standard non-invasive imaging modality. High quality 3D vessel reconstructions can be acquired using conventional MR scanners together with body surface coils and 3D gradient sequences. The predominant indications for MRAs lie in the diagnostics, planning of vascular interventions and surgery of patients suffering from peripheral artery disease. With high sensitivity and specificity clinically relevant stenoses can be detected and collateral vessels identified. Methodological limitations mainly lie in the imaging of small and peripheral arteries and stented segments. The most important contraindications comprise conventional cardiac pacemakers, implantable defibrillators, paramagnetic implants, and 1st trimester pregnancy. Furthermore, in patients with severe renal failure (glomerular filtration rate of less than 30 ml/min/1.73 m2) gadolinium containing contrast medium should not be used as these patients are at increased risk of development of nephrogenic systemic fibrosis for which no treatment exists. Novel contrast free MRA techniques (e.g. QISS) have been developed and are currently under clinical validation but are not yet widely available.

Alena Welters, Carina Klüppel, Jessica Mrugala, Laura Wörmeyer, Thomas Meissner, Ertan Mayatepek, Christian Heiss, Daniel Eberhard, Eckhard Lammert (2017)NMDAR antagonists for the treatment of diabetes mellitus-Current status and future directions, In: Diabetes, Obesity and Metabolism19(S1)pp. 95-106 Wiley

Diabetes mellitus is characterized by chronically elevated blood glucose levels accelerated by a progressive decline of insulin‐producing β‐cells in the pancreatic islets. Although medications are available to transiently adjust blood glucose to normal levels, the effects of current drugs are limited when it comes to preservation of a critical mass of functional β‐cells to sustainably maintain normoglycemia. In this review, we recapitulate recent evidence on the role of pancreatic N‐methyl‐D‐aspartate receptors (NMDARs) in β‐cell physiology, and summarize effects of morphinan‐based NMDAR antagonists that are beneficial for insulin secretion, glucose tolerance and islet cell survival. We further discuss NMDAR‐mediated molecular pathways relevant for neuronal cell survival, which may also be important for the preservation of β‐cell function and mass. Finally, we summarize the literature for evidence on the role of NMDARs in the development of diabetic long‐term complications, and highlight beneficial pharmacologic aspects of NMDAR antagonists in diabetic nephropathy, retinopathy as well as neuropathy.

Stephan Langer, Niklas Paulus, Christian Heiss, Thomas A. Koeppel, Andreas Greiner, Alexandra Buhl, Thomas Lauer, Maria Kokozidou, Michael J. Jacobs, Gabriele A. Krombach (2011)Cardiovascular remodeling after AVF surgery in rats assessed by a clinical MRI scanner, In: MAGNETIC RESONANCE IMAGING29(1)pp. 57-63 ELSEVIER SCIENCE INC

Purpose To evaluate a cardiovascular magnetic resonance imaging (MRI) technique which allows the longitudinal analysis of cardiovascular remodeling in a rodent femoral arteriovenous fistula (AVF) model by means of a clinical scanner. Materials and Methods Eight rats underwent femoral AVF surgery and four rats served as controls. Vascular and cardiac morphology as well as cardiac function was assessed from Week 3 to 12 using contrast-enhanced, time-resolved magnetic resonance angiography (MRA) and cardiac MRI (cine gradient-echo sequence) at 3 T in one imaging session. Results Arteriovenous surgery resulted in progressive venous dilation and a subsequent cardiac adaptation. This procedure led to downstream vasodilation of the iliac vein and inferior vena cava of 179% and 188%, respectively (3 weeks). To accommodate the increased returning blood volume, cardiac output (CO) increased significantly (P=.014; 6 weeks). This was caused by increased end-diastolic volume (EDV), stroke volume (SV) and heart rate (HR) consistent with an increased volume load. A continuous increase in heart weight peaked at 12 weeks. This increase combined with a distinct end-diastolic left ventricular dilation implied eccentric hypertrophy. Conclusion Small rodent MRI is feasible and clearly depicts fistula maturation and cardiac alterations. This technique proved to be a valuable tool for longitudinal in vivo monitoring in this model, which strongly resembles clinical findings in hemodialysis patients.

Isabel Albers, Erika Zernickel, Manuel Stern, Melanie Broja, Busch Hans Lucas, Christian Heiss, Vera Grotheer, Joachim Windolf, Christoph V. Suschek (2019)Blue light (λ=453 nm) nitric oxide dependently induces β-endorphin production of human skin keratinocytes in-vitro and increases systemic β-endorphin levels in humans in-vivo, In: Free Radical Biology and Medicine145pp. 78-86 Elsevier

β-Endorphin exerts a broad spectrum of physiological activity on mood, immune functions, pain management, reward effects, and behavioral stability. β-Endorphin is produced in certain neurons within the central and peripheral nervous system but also in the skin, especially in response to ultraviolet radiation. In the present study we have investigated the impact of visible blue light at λ = 453 nm (BL) on β-endorphin production of primary human skin keratinocytes (hKC) in-vitro as well as on systemic β-endorphin formation of whole-body exposed subjects in-vivo. We found that BL irradiation significantly enhanced both keratinocytic β-endorphin production of hKC cultures as well as systemic β-endorphin concentrations in light exposed healthy subjects. Interestingly, in hKC cultures elevated β-endorphin formation was paralleled by significantly increased levels of non-enzymatically generated nitric oxide (NO), whereas elevated systemic β-endorphin values of BL-exposed subjects were accompanied by enhanced systemic concentration of bioactive NO-derivates. These findings point to a pivotal role of NO in the molecular mechanism of the observed BL-induced effects, and indeed, exogenously applied NO was able to significantly enhance β-endorphin production in hKC cultures. Thus, our finding of BL-induced increases in systemic β-endorphin concentration in-vivo can be plausibly explained by an event sequence comprising 1.) BL-driven non-enzymatic formation of NO in the exposed skin tissue, 2.) systemic distribution of cutaneously produced NO in the Form of bioactive nitroso compounds, 3.) a subsequent NO-dependent induction of β-endorphin synthesis in epidermal keratinocytes, and 4.) probably also a NO-dependent modulation of β-endorphin synthesis in specialized neurons within the central and peripheral nervous system.

Hagen Schroeter, Christian Heiss, Jeremy P.E. Spencer, Carl L. Keen, Joanne R. Lupton, Harold H. Schmitz (2010)Recommending flavanols and procyanidins for cardiovascular health: Current knowledge and future needs, In: Molecular Aspects of Medicine31(6)pp. 546-557 Elsevier

Data on the potential health benefits of dietary flavanols and procyanidins, especially in the context of cardiovascular health, are considerable and continue to accumulate. Significant progress has been made in flavanol analytics and the creation of phytonutrient-content food databases, and novel data emanated from epidemiological investigations as well as dietary intervention studies. However, a comprehensive understanding of the pharmacological properties of flavanols and procyanidins, including their precise mechanisms of action in vivo, and a conclusive, consensus-based accreditation of a causal relationship between intake and health benefits in the context of primary and secondary cardiovascular disease prevention is still outstanding. Thus, the objective of this review is to identify and discuss key questions and gaps that will need to be addressed in order to conclusively demonstrate whether or not dietary flavanols and procyanidins have a role in preventing, delaying the onset of, or treating cardiovascular diseases, and thus improving human life expectancy and quality of life.

C. Meyer, E. Göpel, J. Siegrist, C. Heiss, M. Kelm, T. Rassaf (2011)Lifestyle modification programs protecting cardiovascular health in Germany and Sweden, In: Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz54(2)pp. 213-220 Springer-Verlag

A large amount of evidence, including neurohumoral, inflammatory, and metabolic physiological adaptations, emphasize the importance of the individual lifestyle as a public health concern. The related burden of chronic diseases in the European Union, which could be minimized by appropriate lifestyles, requires consistent transfer of evidence-based prevention guidelines. Due to the epidemiologic importance of cardiovascular diseases and innovative health-promoting strategies in Sweden, a comparative analysis between German and Swedish practices preventing cardiovascular events in high-risk populations is presented in this paper. This qualitative analysis demonstrates that lifestyle-related risk and protective factors based on smoking, physical activity, nutrition, and psychosocial determinants are of growing importance in cardiac death prevention. Especially in Sweden, behavioral prevention is joined by condition prevention. In Germany, intersectoral rehabilitation concepts improve patient adherence to behavioral recommendations but interdisciplinary communication between different health experts needs to be improved. The health-promoting hospital composes a health professional's interface, which is based on the understanding that behavioral risk factors are not only highly interrelated, but also require sophisticated healthcare delivery to optimize health management effectiveness.

Christian Heiss, Malte Kelme (2010)Chocolate consumption, blood pressure, and cardiovascular risk, In: European Heart Journal31(13)pp. 1554-1556 Oxford University Press

This editorial refers to ‘Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults’†, by B. Buijsse et al., on page 1616

Andrea Schanz, Margarete Lukosz, Alexandra P Hess, Dunja M Baston-Büst, Jan S Krüssel, Christian Heiss (2015)hCG stimulates angiogenic signals in lymphatic endothelial and circulating angiogenic cells, In: Journal of Reproductive Immunology110pp. 102-108 Elsevier

Human chorionic gonadotropin (hCG) has long been associated with the initiation and maintenance of pregnancy, where angiogenesis plays an important role. However, the function of hCG in angiogenesis and the recruitment of vascular active cells are not fully understood. In this study, the role of hCG and its receptor in circulating angiogenic and human endothelial cells, including lymphatic, uterine microvascular, and umbilical vein endothelial cells, was examined. Immunohistochemistry and immunoblot analysis were used to detect LH/hCG receptor expression and the expression of hCG-induced angiogenic molecules. HIF-1α was determined via ELISA and downstream molecules, such as CXCL12 and CXCR4, via real-time PCR. Chemotaxis was analyzed using Boyden chambers. Our results show that the LH/hCG receptor was present in all tested cells. Furthermore, hCG was able to stimulate LH/hCG-receptor-specific migration in a dose-dependent fashion and induce key angiogenic molecules, including HIF-1α, CXCL12, and CXCR4. In conclusion, our findings underscore the importance of hCG as one of the first angiogenic molecules produced by the conceptus. hCG itself alters endothelial motility, recruitment, and expression of pro-angiogenic molecules and may therefore play an important role in vascular adaption during implantation and early placental formation.

Christian Heiss, C. L. Keen, M. Kelm (2010)Flavanols and cardiovascular disease prevention, In: European Heart Journal31(21)pp. 2583-2592 Oxford University Press

Diet is a major lifestyle factor in the primary and secondary prevention of numerous chronic diseases, including myocardial infarction, stroke, and diabetes. Epidemiological studies suggest that the beneficial cardiovascular health effects of diets rich in fruits and vegetables are in part mediated by their flavonoid content, with particular benefits provided by one member of this family, the flavanols. This concept is supported by findings from small-scale intervention studies with surrogate endpoints including endothelium-dependent vasodilation, blood pressure, platelet function, and glucose tolerance. Mechanistically, short-term effects on endothelium-dependent vasodilation following the consumption of flavanol-rich foods, as well as purified flavanols, have been linked to an increased nitric oxide bioactivity in healthy humans, and those with increased cardiovascular risk. The critical biological target(s) for flavanols have yet to be identified and the extent to which these acute results are important in the context of long-term human health is unknown. While flavanols represent a promising class of food components with respect to their ability to lower cardiovascular risk the flavanol-rich foods used in many trials have been poorly defined with respect to their flavanol content and flavanol-isomer profile; several studies have lacked appropriate controls, and the long-term randomized controlled intervention trials with flavanol-rich foods are missing. Thus, while the literature regarding flavanols and vascular health is encouraging, more in-depth and well-controlled clinical and experimental studies are needed to better define the potential protective vascular effects of these nutrients and their therapeutic value in cardiovascular medicine.

Ana Rodriguez-Mateos, Timon Weber, Simon Skene, Javier I Ottaviani, Alan Crozier, Malte Kelm, Hagan Schroeter, Christian Heiss (2018)Assessing the respective contributions of dietary flavanol monomers and procyanidins in mediating cardiovascular effects in humans: Randomized-controlled, double-masked intervention trial, In: The American Journal of Clinical Nutrition108(6)nqy229pp. 1229-1237 American Society for Nutrition

Background: Flavanols are an important class of food bioactives that can improve vascular function even in healthy subjects. Cocoa flavanols (CFs) are comprised principally of the monomer, (−)-epicatechin (~20%) with a degree of polymerisation of 1 (DP1), and oligomeric procyanidins (~80%, DP2-10). Objective: To investigate the relative contribution of procyanidins and (−)-epicatechin to CF intake-related improvements in vascular function in healthy volunteers. Design: In a randomized, controlled, double-masked, parallel-group dietary intervention trial, 45 healthy men, (18-35 years), consumed once daily for 1 month (a) a DP1-10 cocoa extract containing 130 mg of (−)-epicatechin and 560 mg of procyanidins (b) a DP2-10 cocoa extract containing 20 mg (−)-epicatechin and 540 mg procyanidins or (c) a Control that was flavanol-free with identical micro- and macronutrient composition. ( NCT02728466) Results: Consumption of DP1-10, but neither DP2-10 nor the Control, significantly increased flow-mediated vasodilation (primary endpoint), and the level of structurally-related (−)-epicatechin metabolites (SREMs) in the circulatory system, while decreasing pulse wave velocity and blood pressure. Total cholesterol significantly decreased after daily intake of both DP1-10 and DP2-10 as compared to the Control. Conclusions: CF-related improvements in vascular function predominantly relate to intake of flavanol monomers and circulating SREMs in healthy humans, but not to the more abundant procyanidins and gut microbiome-derived CF-catabolites. Reduction in total cholesterol was linked to consumption of procyanidins but not necessarily that of (-)-epicatechin.

Javier I. Ottaviani, Tony Y. Momma, Christian Heiss, Catherine Kwik-Uribe, Hagen Schroeter, Carl L. Keen (2011)The stereochemical configuration of flavanols influences the level and metabolism of flavanols in humans and their biological activity in vivo, In: FREE RADICAL BIOLOGY AND MEDICINE50(2)pp. 237-244 ELSEVIER SCIENCE INC

Abstract Extensive epidemiological and clinical evidence associates diets high in flavanol-containing foods with cardiovascular health benefits in humans. Catechin and epicatechin, the most common flavanols in foods, are present in the diet in different enantiomeric forms. This study investigated the influence of the stereochemical configuration of flavanols on their absorption, metabolism, and biological activity. Healthy adult males were asked to consume equal amounts of the stereochemically pure flavanols (−)­epicatechin, (−)­catechin, (+)­catechin, and (+)­epicatechin (1.5 mg/kg bw) in a well-defined cocoa-based, dairy-containing drink matrix, and flavanol levels were subsequently determined in plasma and 24-h urine. The results obtained show that the stereochemical configuration of flavanols has a profound influence on their uptake and metabolism in humans. In addition, we assessed the vasodilatory activity of each flavanol stereoisomer in vivo and found (−)-epicatechin to be the single stereoisomer capable of mediating a significant arterial dilation response. Importantly, this effect was independent of the classic antioxidant properties of flavanols. Overall, these results indicate that the proposed beneficial health effects associated with the consumption of flavanol-containing foods will significantly depend on the stereochemical configuration of the flavanols ingested.

Anna Vogiatzoglou, Angela A Mulligan, Amit Bhaniani, Marleen A.H Lentjes, Alison McTaggart, Robert N. Luben, Christian Heiss, Malte Kelm, Marc W. Merx, Jeremy P.E Spencer, Hagen Schroeter, Kay-Tee Khaw, Gunter G.C. Kuhnle (2015)Associations between flavan-3-ol intake and CVD risk in the Norfolk cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk), In: Free Radical Biology and Medicine84pp. 1-10 Elsevier

Dietary intervention studies suggest that flavan-3-ol intake can improve vascular function and reduce the risk of cardiovascular diseases (CVD). However, results from prospective studies failed to show a consistent beneficial effect. Associations between flavan-3-ol intake and CVD risk in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) were investigated. Data were available from 24,885 (11,252 men; 13,633 women) participants, recruited between 1993 and 1997 into the EPIC-Norfolk study. Flavan-3-ol intake was assessed using 7-day food diaries and the FLAVIOLA Flavanol Food Composition database. Missing data for plasma cholesterol and vitamin C were imputed using multiple imputation. Associations between flavan-3-ol intake and blood pressure at baseline were determined using linear regression models. Associations with CVD risk were estimated using Cox regression analyses. Median intake of total flavan-3-ols was 1034 mg/d (range: 0–8531 mg/d) for men and 970 mg/d (0–6695 mg/d) for women, median intake of flavan-3-ol monomers was 233 mg/d (0–3248 mg/d) for men and 217 (0–2712 mg/d) for women. There were no consistent associations between flavan-3-ol monomer intake and baseline systolic and diastolic blood pressure (BP). After 286,147 person-years of follow-up, there were 8463 cardiovascular events and 1987 CVD related deaths; no consistent association between flavan-3-ol intake and CVD risk (HR 0.93, 95% CI: 0.87; 1.00; Q1 vs Q5) or mortality was observed (HR 0.93, 95% CI: 0.84; 1.04). Flavan-3-ol intake in EPIC-Norfolk is not sufficient to achieve a statistically significant reduction in CVD risk.

Ulrich Sydlik, Henrike Peuschel, Adnana Paunel-Görgülü, Stefanie Keymel, Ursula Krämer, Alexander Weissenberg, Matthias Kroker, Samira Seghrouchni, Christian Heiss, Joachim Windolf, Andreas Bilstein, Malte Kelm, Jean Krutmann, Klaus Unfried (2012)Recovery of neutrophil apoptosis by ectoine: a new strategy against lung inflammation, In: European Respiratory Journal41(2)pp. 433-442 European Respiratory Society

The life span of neutrophilic granulocytes has determining impact on the intensity and duration of neutrophil driven lung inflammation. Based on the compatible solute ectoine, we aimed to prevent anti-apoptotic reactions in neutrophils triggered by the inflammatory microenvironment in the lung. Neutrophils from COPD patients and control individuals were exposed to inflammatory mediators and xenobiotics in the presence or absence of ectoine. The in vivo relevance of this approach was tested in xenobiotic-induced lung inflammation in rats. The reduction of apoptosis rates of ex vivo exposed neutrophils from persons of all study groups was significantly restored in the presence of ectoine. However, natural apoptosis rates not altered by inflammatory stimuli were not changed by ectoine. Mechanistic analyses demonstrated the preventive effect of ectoine on the induction of anti-apoptotic signalling. Neutrophilic lung inflammation induced by single or multiple exposition of animals to environmental particles was reduced after the therapeutic intervention with ectoine. Analyses of neutrophils from bronchoalveolar lavage indicate that the in vivo effect is due to the restoration of neutrophil apoptosis. Ectoine, a compound of the highly compliant group of compatible solutes, demonstrates a reproducible and robust effect on the resolution of lung inflammation.

Ana Rodriguez-Mateos, Catarina Rendeiro, Triana Bergillos-Meca, Setareh Tabatabaee, Trevor W George, Christian Heiss, Jeremy PE Spencer (2013)Intake and time dependence of blueberry flavonoid–induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity, In: American Journal of Clinical Nutrition98(5)pp. 1179-1191 American Society for Nutrition

Background: There are very limited data regarding the effects of blueberry flavonoid intake on vascular function in healthy humans. Objectives: We investigated the impact of blueberry flavonoid intake on endothelial function in healthy men and assessed potential mechanisms of action by the assessment of circulating metabolites and neutrophil NADPH oxidase activity. Design: Two randomized, controlled, double-blind, crossover human-intervention trials were conducted with 21 healthy men. Initially, the impact of blueberry flavonoid intake on flow-mediated dilation (FMD) and polyphenol absorption and metabolism was assessed at baseline and 1, 2, 4, and 6 h after consumption of blueberry containing 766, 1278, and 1791 mg total blueberry polyphenols or a macronutrient- and micronutrient-matched control drink (0 mg total blueberry polyphenols). Second, an intake-dependence study was conducted (from baseline to 1 h) with 319, 637, 766, 1278, and 1791 mg total blueberry polyphenols and a control. Results: We observed a biphasic time-dependent increase in FMD, with significant increases at 1–2 and 6 h after consumption of blueberry polyphenols. No significant intake-dependence was observed between 766 and 1791 mg. However, at 1 h after consumption, FMD increased dose dependently to ≤766 mg total blueberry polyphenol intake, after which FMD plateaued. Increases in FMD were closely linked to increases in circulating metabolites and by decreases in neutrophil NADPH oxidase activity at 1–2 and 6 h. Conclusions: Blueberry intake acutely improves vascular function in healthy men in a time- and intake-dependent manner. These benefits may be mechanistically linked to the actions of circulating phenolic metabolites on neutrophil NADPH oxidase activity. This trial was registered at as NCT01292954 and NCT01829542.

Christian Heiss, Juraj Madaric, Jill Belch, Marianne Brodmann, Lucia Mazzolai (2019)The compelling arguments for the need of medical vascular physicians in Europe, In: Vasapp. 1-5 Hogrefe

The burden of vascular diseases is growing worldwide, as the population ages, prompting a call to action not only in terms of awareness but also and most urgently in recognizing the need for vascular physicians, also called angiologists. Vascular medicine views the vascular system (arteries, veins, and lymphatics) as a whole, unique, and independent entity requiring specialized competencies. Vascular physicians offer a holistic and comprehensive approach to vascular patients including provision of interventional procedures, management of a heterogeneous group of multi-morbid and frail patients affected by multi-vessel diseases, and connecting different specialists in a multidisciplinary effort. Vascular medicine practise varies across European countries. While it is a firmly accepted medical speciality in many European countries it is not formally recognized by the European Union limiting adoption in the other countries. The lack of vascular physicians likely accounts for inequality of care of vascular patients as compared for example to patients with heart disease and might contribute to adverse outcomes and healthcare costs associated with vascular diseases. To move forward in the struggle to provide efficient care for multimorbid poly-vascular patients, it is essential to establish vascular medicine programs in Europe and worldwide. Important steps to achieve this goal include improving public awareness of vascular diseases, attain formal recognition by the EU of angiology/vascular medicine as a medical specialty, creating specialized treatment guidelines, and to harmonize vascular care in Europe.

Roberta R. Holt, Christian Heiss, Malte Kelm, Carl L. Keen (2012)The Potential of Flavanol and Procyanidin Intake to Influence Age-Related Vascular Disease, In: Journal of Nutrition in Gerontology and Geriatrics31(3)pp. 290-323 Taylor & Francis

Advancing age is an independent major risk factor for cardiovascular disease (CVD). Age-associated impairments in the control of inflammation, excessive oxidative stress, and reduced cellular repair can all contribute to the development and progression of CVD. Current recommendations for both the primary and secondary prevention of CVD promote lifestyle modifications that include the adoption of healthy dietary patterns, such as the consumption of diets rich in plant foods, as these have been associated with a lower lifetime risk for the development of CVD. The potential for a diet rich in plant foods to be cardiovascular protective is also supported by prospective studies that suggest the intake of foods providing high amounts of certain phytochemicals, in particular flavanols and procyanidins, reduce the risk for CVD. These observations are further supported by a number of dietary intervention trials that show improvements in vascular function and reduced platelet reactivity following the consumption of high flavanol foods. In the current article we review a selection of these studies, and comment on some of the potential mechanisms that have been postulated to underlie the health effects of flavanol and procyanidin-rich foods.

Dominik Schuler, Roberto Sansone, Christian Heiss, Malte Kelm (2013)Is there a Role for Antioxidants in the Treatment of Stable Angina?, In: Current Pharmaceutical Design19(9)pp. 1601-1615 Bentham Science

Medical treatment plays an important role in the therapy of coronary artery disease and stable angina. Whereas nitrates are used to improve symptoms, beta-blockers, statins, and ACE-inhibitors/angiotensin receptor blockers are given also to target prognosis in part by slowing the progression of disease. Major cardiovascular risk factors including tobacco smoking, physical inactivity, obesity, arterial hypertension, hyperlipidemia, and diabetes mellitus were associated with overproduction of reactive oxygen species (ROS). In animal models, increased ROS production was associated with the initial steps of atherosclerosis including vascular cell dysfunction, intimal hypertrophy, the formation and destabilization of plaque. As a consequence, ROS were believed to be major contributors to the development of cardiovascular diseases and antioxidant treatments were proposed as promising therapeutic strategies. Nevertheless, intervention studies with antioxidant vitamins have failed to positively affect cardiovascular outcome in prospective trials. Specific inhibitors of prooxidant enzymes are being developed but their efficacy to improve cardiovascular endpoints has not been tested so far. Newer evidence suggests that phytonutrients including flavanols may posses vascular protective effects that are independent of their antioxidant properties observed in vitro. Taken together, there is currently not enough evidence that treatment with antioxidants per se will play a role in cardiovascular medicine.

Stefanie Keymel, Benedikt Schueller, Roberto Sansone, Rabea Wagstaff, Stephan Steiner, Malte Kelm, Christian Heiss (2016)Oxygen dependence of endothelium-dependent vasodilation: importance in chronic obstructive pulmonary disease, In: Archives of Medical Science14(2)pp. 297-306 Termedia Publishing

Introduction: Epidemiological studies have shown increased morbidity and mortality in patients with coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD). We aimed to characterize the oxygen dependence of endothelial function in patients with CAD and coexisting COPD. Go to: Material and methods: In CAD patients with and without COPD (n = 33), we non-invasively measured flow-mediated dilation (FMD) and intima-media thickness (IMT) of the brachial artery (BA), forearm blood flow (FBF), and perfusion of the cutaneous microcirculation with laser Doppler perfusion imaging (LDPI). In an experimental setup, vascular function was assessed in healthy volunteers (n = 5) breathing 12% oxygen or 100% oxygen in comparison to room air. Go to: Results: COPD was associated with impaired FMD (3.4 ±0.5 vs. 4.2 ±0.6%; p < 0.001) and increased IMT (0.49 ±0.04 vs. 0.44 ±0.04 mm; p 65 mm Hg and pO2 ≤ 65 mm Hg revealed even lower FMD in patients with lower pO2 (3.0 ±0.5 vs. 3.7 ±0.4%; p < 0.01). Multivariate analysis showed that pO2 was a predictor of FMD independent of the forced expiratory volume and pack years. Exposure to hypoxic air led to an acute decrease in FMD, whereby exposure to 100% oxygen did not change vascular function. Conclusions: Our data suggest that in CAD patients with COPD, decreased systemic oxygen levels lead to endothelial dysfunction, underlining the relevance of cardiopulmonary interaction and the potential importance of pulmonary treatment in secondary prevention of vascular disease.

Patrick Horn, Nicolas Amabile, Franca S. Angeli, Roberto Sansone, Berthold Stegemann, Malte Kelm, Matthew L. Springer, Yerem Yeghiazarians, Hagen Schroeter, Christian Heiss (2014)Dietary flavanol intervention lowers the levels of endothelial microparticles in coronary artery disease patients, In: BRITISH JOURNAL OF NUTRITION111(07)pp. 1245-1252 CAMBRIDGE UNIV PRESS

Current evidence suggests that regenerative v. degenerative endothelial responses can be integrated in a clinical endothelial phenotype, reflecting the net result between damage from risk factors and endogenous repair capacity. We have previously shown that a cocoa flavanol (CF) intervention can improve endothelial function and increase the regenerative capacity of the endothelium by mobilising circulating angiogenic cells in patients with coronary artery disease (CAD). The aim of the present study was to investigate whether CF can lower the levels of circulating endothelial microparticles (EMP), markers of endothelial integrity, along with improvements in endothelial function. The levels of EMP in the frozen plasma samples of CAD patients were measured along with endothelial function (flow-mediated vasodilation, FMD); n 16, FMD data published previously), and these data were compared with those of young (n 12) and age-matched (n 12) healthy control subjects. The CAD patients exhibited significantly increased levels of EMP along with impaired FMD when compared with the healthy control subjects. The levels of CD144+ and CD31+/41− EMP were inversely correlated with FMD (r − 0·67, P= 0·01 and r − 0·59, P= 0·01, respectively). In these CAD patients, the levels of EMP were measured after they had consumed a drink containing 375 mg of CF (high-CF intervention, HiFI) or 9 mg of CF (macro- and micronutrient-matched low-CF control, LoFl) twice daily over a 30-d period in a randomised, double-blind, cross-over study. After 1 month of HiFI, the levels of CD31+/41− and CD144+ EMP decreased ( − 25 and − 23 %, respectively), but not after LoFl. Our data show that flavanols lower the levels of EMP along with higher endothelial function, lending evidence to the novel concept that flavanols may improve endothelial integrity.

Carina Henning, Anna Branopolskia, Paula Follert, Oksana Lewandowska, Aysel Ayhan, Marcel Benkhoff, Ulrich Flögel, MALTE KELM, CHRISTIAN HEISS, Eckhard Lammert (2020)Endothelial β1 integrin-mediated adaptation to myocardial ischemia, In: Thrombosis and Haemostasis

Background: Short episodes of myocardial ischemia can protect from myocardial infarction. However, the role of endothelial β1 integrin in these cardioprotective ischemic events is largely unknown. Objective: In this study we investigated whether endothelial β1 integrin is required for cardiac adaptation to ischemia and protection from myocardial infarction. Methods: Here we introduced transient and permanent left anterior descending artery (LAD) occlusions in mice. We inhibited β1 integrin by intravenous injection of function-blocking antibodies and tamoxifen-induced endothelial cell (EC)-specific deletion of Itgb1. Furthermore, human ITGB1 was silenced in primary human coronary artery ECs using siRNA. We analyzed the numbers of proliferating ECs and arteries by immunohistochemistry, determined infarct size by magnetic resonance imaging (MRI) and TTC staining, and analyzed cardiac function by MRI and echocardiography. Results: Transient LAD occlusions were found to increase EC proliferation and arteriole formation in the entire myocardium. These effects required β1 integrin on ECs, except for arteriole formation in the ischemic part of the myocardium. Furthermore, this integrin subunit was also relevant for basal and mechanically-induced proliferation of human coronary artery ECs. Notably, β1 integrin was needed for cardioprotection induced by transient LAD occlusions, and the absence of endothelial β1 integrin resulted in impaired growth of blood vessels into the infarcted myocardium and reduced cardiac function after permanent LAD occlusion. CONCLUSIONS: We showed that endothelial β1 integrin is required for adaptation of the heart to cardiac ischemia and protection from myocardial infarction.

Carina Henning, Anna Branopolski, Dominik Schuler, Dimitrios Dimitroulis, Patrik Huelsemann, Christopher Nicolaus, Roberto Sansone, Jelle Ludolf Postma, Daniel Eberhard, Ferdinand Le Noble, Malte Kelm, Eckhard Lammert, Christian Heiss (2019)Requirement of β1 integrin for endothelium-dependent vasodilation and collateral formation in hindlimb ischemia, In: Scientific Reports Nature Research

An acute increase in blood flow triggers flow-mediated dilation (FMD), which is mainly mediated by endothelial nitric oxide synthase (eNOS). A long-term increase in blood flow chronically enlarges the arterial lumen, a process called arteriogenesis. In several common human diseases, these processes are disrupted for as yet unknown reasons. Here, we asked whether β1 integrin, a mechanosensory protein in endothelial cells, is required for FMD and arteriogenesis in the ischemic hindlimb. Permanent ligation of the femoral artery in C57BL/6J mice enlarged pre-existing collateral arteries and increased numbers of arterioles in the thigh. In the lower leg, the numbers of capillaries increased. Notably, injection of β1 integrin-blocking antibody or tamoxifen-induced endothelial cell-specific deletion of the gene for β1 integrin (Itgb1) inhibited both arteriogenesis and angiogenesis. Using high frequency ultrasound, we demonstrated that β1 integrin-blocking antibody or endothelial cell-specific depletion of β1 integrin attenuated FMD of the femoral artery, and blocking of β1 integrin function did not further decrease FMD in eNOS-deficient mice. Our data suggest that endothelial β1 integrin is required for both acute and chronic widening of the arterial lumen in response to hindlimb ischemia, potentially via functional interaction with eNOS.

Alexander Rodway, Michelle Stafford, Sophie Wilding, Nikolaos Ntagiantas, Vasileios Patsiogiannis, Charlotte Allan, Ben Field, James Clark, Felipe Pazos Casal, Ajay Pankhania, Thomas Loosemore, Christian Heiss (2021)Day case angioplasty in a secondary care setting – initial experience, In: VASApp. 1-7 Hogrefe AG

Background: Peripheral artery disease presents an increasing healthcare burden worldwide. Day-case angioplasty in a secondary care setting can be a safe and effective means of meeting the growing demand for lower limb revascularisation. We evaluated the safety and efficacy of a day-case-based angioplasty service in a UK district general hospital. Patients and methods: Consecutive patients undergoing endovascular revascularisation between August 2018–February 2020 were analysed retrospectively. All patients were discussed at a multi-disciplinary (diabetic foot) team meeting following a day case algorithm. Patient and procedural characteristics, technical success, peri-procedural complications, and 30-day outcome of day-case angioplasties were compared with those requiring overnight stay or were hospitalized. Results: Fifty-seven percent of 138 patients were diabetic, mean age 75 ± 12 years, 95% had critical limb ischaemia (Fontaine III 12%, IV 83%), and baseline ankle brachial pressure index [ABPI] 0.40 ± 0.30. Sixty-three patients (45%) were treated as planned day cases, 21 (15%) required overnight admission for social indications. Fifteen (11%) were planned admissions with the need for sequential debridement procedures, and 39 (28%) were already hospitalised at the time of referral to the vascular service. The overall technical success was 92% and not successful procedures mainly occurred in patients > 80 years. The ABPI increased at the initial follow-up to 0.84 ± 0.18. Fifty-three percent required treatment of > 1 level, 80% included recanalisations of chronic total occlusions, and average total lesion length was 133 ± 90 mm. Closure devices were employed in all cases. There were no major peri-procedural complications. A single minor access-site related bleeding episode (0.8%) occurred, requiring 24 h observation in hospital. While significantly more wounds had closed in out-patients, the mortality, major amputation and target lesion revascularization did not differ between groups. Conclusions: Safe and effective day-case-based angioplasty can be provided in a secondary care setting for patients with critical limb ischaemia needing complex multi-level procedures.

Coronaviruses (CoVs) are single-stranded RNA viruses which following virus attachment and entry into the host cell, particularly type 2 pneumocytes but also endothelial cells, release RNA into cytosol where it serves as a matrix for the host translation machinery to produce viral proteins. The viral RNA in cytoplasm can interact with host cell microRNAs which can degrade viral RNA and/or prevent viral replication. As such host cellular miRNAs represent key cellular mediators of antiviral defense. Polyphenols, plant food bioactives, exert antiviral properties, which is partially due to their capacity to modulate the expression of miRNAs. The objective of this work was to assess if polyphenols can play a role in prevention of SARS-CoV-2 associated complications by modulating the expression of host miRNAs. To test this hypothesis, we performed literature search to identify miRNAs that could bind SARS-CoV-2 RNA as well as miRNAs which expression can be modulated by polyphenols in lung, type 2 pneumocytes or endothelial cells. We identified over 600 miRNAs that have capacity to bind viral RNA and 125 miRNAs which expression can be modulated by polyphenols in the cells of interest. We identified that there are 17 miRNAs with both the capacity to bind viral RNA and which expression can be modulated by polyphenols. Some of these miRNAs have been identified as having antiviral properties or can target genes involved in regulation of processes of viral replication, apoptosis or viral infection. Taken together this analysis suggests that polyphenols could modulate expression of miRNAs in alveolar and endothelial cells and exert antiviral capacity.

CHRISTIAN HEISS, (2021)Experimental evidence that (–)-epicatechin and anthocyanins modulate GLP-1 metabolism: Relevant for humans?, In: Journal of Nutrition Oxford University Press

Flavanols, in particular (-)-epicatechin (EC) and anthocyanins (AC) are among the most abundant plant food bioactives present in the diet. Both epidemiological and clinical dietary intervention trials support their cardiometabolic health benefits.(1-3) Intervention trials have shown consistent and promising effects upon their consumption on biomarkers of human cardiometabolic health including improvements in endothelial function, blood pressure, blood lipids and glucose metabolism in healthy, at risk and diseased people. However, the mechanisms of action are still not entirely understood. In a paper published in this issue of The Journal of Nutrition, Cremonini et al. (4) demonstrate in mice and GLUTag cells, a model of enteroendocrine L cells, how EC, different ACs and AC metabolites increase glucagon-like peptide-1 (GLP-1) by modulation of its metabolism.

CHRISTIAN HEISS (2021)Low carotid intima media thickness excludes lower limb peripheral artery disease, In: VASA - European Journal of Vascular Medicine Hogrefe
Luc Bergougnan, Grit Andersen, Leona Plum-Mörschel, Maria Francesca Evaristi, Bruno Poirier, Agnes Tardat, Marcel Ermer, Theresa Herbrand, Jorge Arrubla, Hans Veit Coester, Roberto Sansone, Christian Heiss, Olivier Vitse, Fabrice Hurbin, Rania Boiron, Xavier Benain, David Radzik, Philip Janiak, Anthony J Muslin, Lionel Hovsepian, Stephane Kirkesseli, Paul Deutsch, Ashfaq A Parkar (2020)Endothelial-protective effects of a G-protein-biased sphingosine-1 phosphate receptor-1 agonist, SAR247799, in type-2 diabetes rats and a randomized placebo-controlled patient trial, In: British journal of clinical pharmacologypp. 1-18

AIMSSAR247799 is a G-protein-biased sphingosine-1 phosphate receptor-1 (S1P1 ) agonist designed to activate endothelial S1P1 and provide endothelial-protective properties, while limiting S1P1 desensitization and consequent lymphocyte-count reduction associated with higher doses. The aim was to show whether S1P1 activation can promote endothelial effects in patients and, if so, select SAR247799 doses for further clinical investigation. METHODSType-2 diabetes patients, enriched for endothelial dysfunction (flow-mediated dilation, FMD

Christian Heiss, Ana Rodriguez-Mateos, Malte Kelm (2015)Central Role of eNOS in the Maintenance of Endothelial Homeostasis, In: Antioxidants & Redox Signaling22(14)pp. 1230-1242 Mary Ann Liebert

Significance: Disruption of endothelial function is considered a key event in the development and progression of atherosclerosis. Endothelial nitric oxide synthase (eNOS) is a central regulator of cellular function that is important to maintain endothelial homeostasis. Recent Advances: Endothelial homeostasis encompasses acute responses such as adaption of flow to tissue's demand and more sustained responses to injury such as re-endothelialization and sprouting of endothelial cells (ECs) and attraction of circulating angiogenic cells (CAC), both of which support repair of damaged endothelium. The balance and the intensity of endothelial damage and repair might be reflected by changes in circulating endothelial microparticles (EMP) and CAC. Flow-mediated vasodilation (FMD) is a generally accepted clinical read-out of NO-dependent vasodilation, whereas EMP are upcoming prognostically validated markers of endothelial injury and CAC are reflective of the regenerative capacity with both expressing a functional eNOS. These markers can be integrated in a clinical endothelial phenotype, reflecting the net result between damage from risk factors and endogenous repair capacity with NO representing a central signaling molecule. Critical Issues: Improvements of reproducibility and observer independence of FMD measurements and definitions of relevant EMP and CAC subpopulations warrant further research. Future Directions: Endothelial homeostasis may be a clinical therapeutic target for cardiovascular health maintenance.

Bernardo Meza-Torres, Fabrizio Carinci, Christian Heiss, Mark Joy, Simon de Lusignan (2021)Health service organisation impact on lower extremity amputations in people with type 2 diabetes with foot ulcers: systematic review and meta-analysis, In: Acta Diabetologicapp. 1-13

Despite the evidence available on the epidemiology of diabetic foot ulcers and associated complications, it is not clear how specific organizational aspects of health care systems can positively affect their clinical trajectory. We aim to evaluate the impact of organizational aspects of care on lower extremity amputation rates among people with type 2 diabetes affected by foot ulcers. We conducted a systematic review of the scientific literature published between 1999 and 2019, using the following key terms as search criteria: people with type 2 diabetes, diagnosed with diabetic foot ulcer, treated with specific processes and care pathways, and LEA as primary outcome. Overall results were reported as pooled odds ratios and 95% confidence intervals obtained using fixed and random effects models. A total of 57 studies were found eligible, highlighting the following arrangements: dedicated teams, care pathways and protocols, multidisciplinary teams, and combined interventions. Among them, seven studies qualified for a meta-analysis. According to the random effects model, interventions including any of the four arrangements were associated with a 29% reduced risk of any type of lower extremity amputation (OR = 0.71; 95% CI 0.52-0.96). The effect was larger when focusing on major LEAs alone, leading to a 48% risk reduction (OR = 0.52; 95% CI 0.30-0.91). Specific organizational arrangements including multidisciplinary teams and care pathways can prevent half of the amputations in people with diabetes and foot ulcers. Further studies using standardized criteria are needed to investigate the cost-effectiveness to facilitate wider implementation of improved organizational arrangements. Similarly, research should identify specific roadblocks to translating evidence into action. These may be structures and processes at the health system level, e.g. availability of professionals with the right skillset, reimbursement mechanisms, and clear organizational intervention implementation guidelines.

Christian Heiss (2019)Electronic cigarettes: Replacing one evil with another?, In: European Journal of Preventive Cardiology26(11)pp. 1217-1218 SAGE Publications

Cigarette smoking is still the most important avoidable cardiovascular risk factor. The World Health Organization estimates that 20.2% (34.1% male, 6.1% females) of the world’s population aged ≥15 years were current smokers in 2015. Within non-communicable diseases, tobacco use is estimated to be responsible for 10% of all deaths from cardiovascular diseases, 22% of all cancer deaths and 36% of all deaths from diseases of the respiratory system. Recent data suggest that tobacco smoking may also increase the risk of atrial fibrillation. Electronic cigarettes may be an effective way to assist with smoking cessation. A recent randomized trial demonstrated that electronic cigarettes were more effective for smoking cessation at one year than nicotine replacement therapy. However, the smoking cessation rate was only 18%, and among participants with one-year abstinence, 80% of those in the e-cigarette group were still using electronic cigarettes. This brings up the question of whether this approach merely replaces one evil with another. Clearly, knowledge on the safety of electronic cigarettes is critical in answering this question.

Ana Rodriguez-Mateos, Geoffrey Istas, Lisa Boschek, Rodrigo P Feliciano, Charlotte E Mills, Céline Boby, Sergio Gomez-Alonso, Dragan Milenkovic, Christian Heiss (2019)Circulating anthocyanin metabolites mediate vascular benefits of blueberries: insights from randomized controlled trials, metabolomics, and nutrigenomics, In: The Journals of Gerontology: Series A74(7)pp. p 967-976 Oxford University Press (OUP)

Potential health benefits of blueberries may be due to vascular effects of anthocyanins which predominantly circulate in blood as phenolic acid metabolites. We investigated which role blueberry anthocyanins and circulating metabolites play in mediating improvements in vascular function and explore potential mechanisms using metabolomics and nutrigenomics. Purified anthocyanins exerted a dose-dependent improvement of endothelial function in healthy humans, as measured by flow-mediated dilation (FMD). The effects were similar to those of blueberries containing similar amounts of anthocyanins while control drinks containing fiber, minerals, or vitamins had no significant effect. Daily 1-month blueberry consumption increased FMD and lowered 24h-ambulatory-systolic-blood-pressure. Of the 63 anthocyanin plasma metabolites quantified, 14 and 17 correlated with acute and chronic FMD improvements, respectively. Injection of these metabolites improved FMD in mice. Daily blueberry consumption led to differential expression (>1.2-fold) of 608 genes and 3 microRNAs, with Mir-181c showing a 13-fold increase in peripheral blood mononuclear cells. Patterns of 13 metabolites were independent predictors of gene expression changes and pathway enrichment analysis revealed significantly modulated biological processes involved in cell adhesion, migration, immune response, and cell differentiation. Our results identify anthocyanin metabolites as major mediators of vascular bioactivities of blueberries and changes of cellular gene programs.

L Busch, M Kelm, Christian Heiss (2014)Biomarker der Plaqueruptur, In: Kompendium Herz Kreislauf.30pp. 6-12 Thieme
R Sansone, Christian Heiss (2014)Kaffee und Tee – schlecht oder gut für den Blutdruck?, In: Druckpunkte
Y. Heinen, E. Stegemann, R. Sansone, K. Benedens, R. Wagstaff, J. Balzer, T. Rassaf, T. Lauer, M. Kelm, C. Heiss (2015)Local Association Between Endothelial Dysfunction and Intimal Hyperplasia: Relevance in Peripheral Artery Disease, In: Journal of the American Heart Association4(2)pp. e001472-e001472 Wiley

Background Endothelial dysfunction is a key factor in the development of atherosclerosis. Commonly, endothelial function is determined in the brachial artery, whereas patients with peripheral artery disease (PAD) present with lower limb atherosclerosis. We hypothesized that in PAD, a segmental or local association exists between endothelial dysfunction and atherosclerotic structural changes. Methods and Results We used ultrasound to study endothelial function as flow‐mediated vasodilation, intima media thickness, and local stiffness of the superficial femoral artery (SFA) and brachial artery (BA). PAD patients with symptomatic SFA or below‐the‐knee disease were compared with age‐matched patients without PAD and young healthy controls. PAD patients with SFA or below‐the‐knee disease exhibited endothelial dysfunction of the proximal SFA (flow‐mediated vasodilation: 3.9±0.6%, 3.7±0.6%) compared with healthy controls (7.4±1.0%) and patients without PAD (5.4±0.6%). Brachial artery flow‐mediated vasodilation values were not different in PAD patients with SFA or below‐the‐knee disease compared with patients without PAD, but they were significantly lower than those of healthy controls. Endothelial dysfunction correlated with increased intima media thickness or plaque thickness at the site of flow‐mediated vasodilation measurement across vascular sites. In PAD patients with SFA disease, SFA flow‐mediated vasodilation was further impaired within and distal to stenosis (prestenosis 3.9±0.6%, intrastenosis 2.3±0.7%, poststenosis 2.5±0.6%) and recovered within 24 hours after SFA balloon angioplasty to prestenotic values but not to the brachial artery or SFA values in patients without PAD or controls. Conclusion A close association exists between local endothelial function and atherosclerotic structural remodeling, suggesting that in PAD, local and segmental factors—in addition to systemic factors—influence local endothelial function. Our data point toward a pathophysiological role for lower extremity endothelial dysfunction in PAD.

Anna Vogiatzoglou, Angela A. Mulligan, Robert N. Luben, Marleen A. H. Lentjes, Christian Heiss, Malte Kelm, Marc W. Merx, Jeremy P. E. Spencer, Hagen Schroeter, Gunter G. C. Kuhnle (2014)Assessment of the dietary intake of total flavan-3-ols, monomeric flavan-3-ols, proanthocyanidins and theaflavins in the European Union, In: BRITISH JOURNAL OF NUTRITION111(08)pp. 1463-1473 CAMBRIDGE UNIV PRESS

Dietary interventions with flavan-3-ols have shown beneficial effects on vascular function. The translation of these findings into the context of the health of the general public requires detailed information on habitual dietary intake. However, only limited data are currently available for European populations. Therefore, in the present study, we assessed the habitual intake of flavan-3-ol monomers, proanthocyanidins (PA) and theaflavins in the European Union (EU) and determined their main food sources using the EFSA (European Food Safety Authority) Comprehensive European Food Consumption Database. Data for adults aged 18–64 years were available from fourteen European countries, and intake was determined using the FLAVIOLA Flavanol Food Composition Database, developed for the present study and based on the latest US Department of Agriculture and Phenol-Explorer databases. The mean habitual intake of flavan-3-ol monomers, theaflavins and PA ranged from 181 mg/d (Czech Republic) to 793 mg/d (Ireland). The highest intakes of flavan-3-ol monomers and theaflavins were observed in Ireland (191/505 mg/d) and the lowest intakes in Spain (24/9 mg/d). In contrast, the daily intake of PA was highest in Spain (175 mg/d) and lowest in The Netherlands (96 mg/d). Main sources were tea (62 %), pome fruits (11 %), berries (3 %) and cocoa products (3 %). Tea was the major single contributor to monomer intake (75 %), followed by pome fruits (6 %). Pome fruits were also the main source of PA (28 %). The present study provides important data on the population-based intake of flavanols in the EU and demonstrates that dietary intake amounts for flavan-3-ol monomers, PA and theaflavins vary significantly across European countries. The average habitual intake of flavan-3-ols is considerably below the amounts used in most dietary intervention studies.

Ana Rodriguez-Mateos, Christian Heiss, Gina Borges, Alan Crozier (2013)Berry (Poly)phenols and Cardiovascular Health, In: Journal of Agricultural and Food Chemistry62(18)pp. 3842-3851 ACS Publications

Berries are a rich source of (poly)phenols, including anthocyanins, flavan-3-ols, procyanidins, flavonols, ellagitannins, and hydroxycinnamates. Epidemiological evidence indicates that the cardiovascular health benefits of diets rich in berries are related to their (poly)phenol content. These findings are supported by small-scale randomized controlled studies (RCTs) that have shown improvements in several surrogate markers of cardiovascular risk such as blood pressure, endothelial function, arterial stiffness, and blood lipids after acute and short-term consumption of blueberries, strawberries, cranberries, or purified anthocyanin extracts in healthy or diseased individuals. However, firm conclusions regarding the preventive value of berry (poly)phenols cannot be drawn due to the small number of existing studies and limitations that apply to the available data, such as lack of controls or failure to assess the absorption and metabolism of (poly)phenols. Although the current evidence is promising, more long-term RCTs are needed to establish the role of berry (poly)phenols to support cardiovascular health

H. Seidel, E. Stegemann, Christian Heiss (2014)Kardiovaskuläre und hämostaseologische Sicht retinaler Gefäßverschlüsse. (Vascular diseases of the retina), In: Der Ophthalmologe111(1)pp. 23-30 Springer

Hintergrund Plötzlich auftretende Sehminderungen sind oft durch akute Gefäßverschlüsse des hinteren Augenabschnitts bedingt und verlaufen schmerzlos. Bei den Gefäßverschlüssen der hinteren Augenabschnitte unterscheidet man arterielle von venösen Okklusionen. Dabei finden sich mit etwa 60 % aller Fälle häufiger venöse als arterielle Verschlüsse. Zusätzlich gibt es jedoch auch Mischbilder. Ziel der Arbeit Der Beitrag bietet eine Zusammenfassung der aktuellen Datenlage zur interdisziplinären Diagnostik und Therapie retinaler Gefäßverschlüsse. Material und Methoden Es erfolgte eine selektive Literaturrecherche unter Berücksichtigung klinisch relevanter kardiovaskulärer und hämostaseologischer Aspekte. Ergebnisse Die ophthalmologische Lokalisation des betroffenen Gefäßsegments kann dem Internisten entscheidende Hinweise für die weiterführende Diagnostik und Therapie geben. Bei arteriellen Verschlüssen muss an ein thromboembolisches Geschehen gedacht, Emboliequellen müssen identifiziert und diese internistisch behandelt werden. Venösen Verschlüssen liegen meist lokale Prozesse auf dem Hintergrund thrombophiler Hämostasestörungen oder blutdruckassoziierte venöse Stase zugrunde. Prognostisch sind die Lokalisation, das Ausmaß, die Dauer und die Intensität der retinalen Ischämie von besonderer Bedeutung. Diskussion Diese Erkrankungen des Auges sind meist eine Folge von internistischen Grunderkrankungen und stellen daher eine interdisziplinäre Herausforderung dar.

D. Schuler, R. Sansone, T. Freudenberger, A. Rodriguez-Mateos, G. Weber, T. Y. Momma, C. Goy, J. Altschmied, J. Haendeler, J. W. Fischer, M. Kelm, C. Heiss (2014)Measurement of Endothelium-Dependent Vasodilation in Mice--Brief Report, In: ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY34(12)pp. 2651-2657 LIPPINCOTT WILLIAMS & WILKINS

Objective — Endothelium-dependent, flow-mediated vasodilation after an increase in shear stress at the endothelial lining of conduit arteries during reactive hyperemia after ischemia is a fundamental principle of vascular physiology adapting blood flow to demand of supplied tissue. Flow-mediated vasodilation measurements have been performed in human studies and are of diagnostic and prognostic importance, but have been impossible because of technical limitations in transgenic mice to date, although these represent the most frequently used animal model in cardiovascular research. Approach and Results — Using high-frequency ultrasound, we visualized, quantified, and characterized for the first time endothelium-dependent dilation of the femoral artery after temporal ischemia of the lower part of the hindlimb and demonstrated that the signaling was almost exclusively dependent on stimulation of endothelial nitric oxide synthase, similar to acetylcholine, completely abolished after pharmacological or genetic inhibition of endothelial nitric oxide synthase and endothelial denudation, substantially impaired in mice of increasing age and cholesterol-fed ApoE knock outs and increased by the dietary polyphenol (−)-epicatechin. Intra- and interindividual variability were similar to the human methodology. Conclusions — The physiology of flow-mediated vasodilation in mice resembles that in humans underscoring the significance of this novel technology to noninvasively, serially, and reliably quantify flow-mediated vasodilation in transgenic mice.—

Ana Rodriguez-Mateos, Raquel Del Pino-García, Trevor W. George, Alberto Vidal-Diez, Christian Heiss, Jeremy P. E. Spencer (2014)Impact of processing on the bioavailability and vascular effects of blueberry (poly)phenols, In: MOLECULAR NUTRITION & FOOD RESEARCH58(10)pp. 1952-1961 WILEY-V C H VERLAG GMBH

Scope Blueberries are a rich source of flavonoids and phenolic acids. Currently, little information is available regarding the impact of processing on the bioavailability and the bioactivity of blueberry (poly)phenols. Methods and results In a randomized, controlled crossover trial, ten healthy volunteers consumed (a) blueberry‐containing baked products, (b) an unprocessed blueberry drink containing the same amount of freeze‐dried blueberry powder as used in the baked products, and (c) matched control baked products. Endothelial function was measured as flow‐mediated dilation (FMD) and plasma samples taken at baseline and at 1, 2, 4, and 6 h postconsumption. Although processing did not significantly change the total (poly)phenolic amount, the processed products contained significantly less anthocyanins (−42%), more chlorogenic acid (23%), no flavanol nonamers or decamers, and significantly more flavanol dimers and trimers (36% and 28%, respectively). FMD increased after 1, 2, and 6 h consumption of the baked products to a similar degree as the unprocessed blueberries, despite significant differences in the levels of individual plasma metabolites. No changes were observed after the consumption of the control product. Conclusion Careful processing can preserve important biological activities of blueberries despite changing the blueberry (poly)phenol composition and plasma metabolite profile.

P. Horn, M. M. Cortese-Krott, N. Amabile, C. Hundsdorfer, K.-D. Kroncke, M. Kelm, C. Heiss (2012)Circulating Microparticles Carry a Functional Endothelial Nitric Oxide Synthase That Is Decreased in Patients With Endothelial Dysfunction, In: Journal of the American Heart Association2(1)pp. e003764-e003764 Wiley

Background-—Microparticles (MPs) are circulating membrane particles of less than a micrometer in diameter shed from endothelial and blood cells. Recent literature suggests that MPs are not just functionally inert cell debris but may possess biological functions and mediate the communication between vascular cells. As a significant proportion of MPs originate from platelets and endothelial cells, we hypothesized that MPs may harbor functional enzymes including an endothelial NO synthase (eNOS). Methods and Results-—Using immunoprecipitation and Western blot analysis, we found that human circulating MPs carry an eNOS. Ca2+ and L-arginine-dependent NOS activity of crude enzyme extract from MPs was determined by measuring the conversion of [3H]-L-arginine to [3H]-citrulline and NOS-dependent nitrite production. NOS-dependent NO production in intact MPs was assessed by the NO-specific fluorescent probe MNIP-Cu. In patients with cardiovascular disease, endothelial dysfunction was associated with an increase in the total number of circulating MPs as well as a significant decrease in the expression and activity of eNOS in MPs. No difference in reactive oxygen species was noted in MPs isolated from either group. Conclusions-—Our data further support the concept that circulating MPs may not only retain phenotypic markers but also preserve the functionality of enzymes of the cells they originate from, including eNOS.

A. Schanz, K. Red-Horse, A.P. Hess, D.M. Baston-Büst, C. Heiss, J.S. Krüssel (2014)Oxygen regulates human cytotrophoblast migration by controlling chemokine and receptor expression, In: Placenta35(12)pp. 1089-1094 Elsevier

Introduction Placental development involves the variation of oxygen supply due to vascular changes and cytotrophoblast invasion. Chemokines and their receptors play an important role during placental formation. Herein, the analysis of the chemokine/receptor pair CXCL12/CXCR4 and further chemokine receptors, such as CCR1, CCR7 and CXCR6 expression in human cytotrophoblasts was conducted. Methods Human cytotrophoblasts were examined directly after isolation or after incubation with different oxygen tensions and a chemical HIF-stimulator for 12 h with realtime PCR, immunoblot, immunohistochemistry. Conditioned media of placental villi, decidua, and endothelial cells was used for ELISA analysis of CXL12. Cytotrophoblast migration assays were conducted applying conditioned media of endothelial cells, a CXCL12 gradient, and different oxygen level. Endometrial and decidual tissue was stained for CXCL12 expression. Results An upregulation of CXCL12, CXCR4, CCR1, CCR7 and CXCR6 was observed after cytotrophoblast differentiation. Low oxygen supply upregulated CXCR4, CCR7 and CXCR6, but downregulated CXCL12 and CCR1. In contrast to the HIF associated upregulation of the aforementioned proteins, downregulation of CXCL12 and CCR1 seemed to be HIF independent. Cytotrophoblast migration was stimulated by low oxygen, the application of a CXCL12 gradient and endothelial cell conditioned media. CXCL12 was detected in endometrial vessels, glands and conditioned media of placental and decidual tissue, but not decidual vessels. Discussion/conclusion Taken together, oxygen supply and cytotrophoblast differentiation seem to be regulators of chemokine and receptor expression and function in human cytotrophoblasts. Therefore, this system seems to be involved in placental development, directed cytotrophoblast migration in the decidual compartment and a subsequent sufficient supply of the growing fetus.

Manuel Stern, Melanie Broja, Roberto Sansone, Michael Gröne, Simon Skene, Joerg Liebmann, Christoph Suschek, Matthias Born, Malte Kelm, Christian Heiss (2018)Blue light exposure decreases systolic blood pressure, arterial stiffness, and improves endothelial function in humans, In: European Journal of Preventive Cardiology25(17)pp. 1875-1883 SAGE Publications

Aims: Previous studies have shown that ultraviolet light can lead to release of nitric oxide (NO) from the skin and decrease blood pressure. In contrast to visible light local application of UV light bears a cancerogenic risk. Here, we investigated whether whole body exposure to visible blue light can also decrease blood pressure and increase endothelial function in healthy subjects. Methods: In a randomized cross-over study, 14 healthy male subjects were exposed on 2 days to monochromatic blue light or blue light with a filter foil (control light) over 30 min. We measured blood pressure (primary endpoint), heart rate, forearm vascular resistance, forearm-blood-flow, endothelial function (flow-mediated dilation), pulse wave velocity, and plasma NO species (NOx), nitrite, and nitroso compounds (RXNO) (secondary endpoints) during and up to 2 hours after exposure. Results: Blue light exposure significantly decreased systolic blood pressure and increased heart rate as compared to control. In parallel, blue light significantly increased forearm-blood-flow, flow-mediated dilation, circulating NOx and RXNO while it decreased forearm vascular resistance and pulse wave velocity. Conclusion: Whole body irradiation with visible blue light at real world doses improves blood pressure, endothelial function, and arterial stiffness by NO released from photolabile intracutanous NO metabolites into circulating blood.

Patrick Horn, Daniel Stern, Verena Veulemans, Christian Heiss, Tobias Zeus, Marc W. Merx, Malte Kelm, Ralf Westenfeld (2015)Improved endothelial function and decreased levels of endothelium-derived microparticles after transcatheter aortic valve implantation, In: EuroIntervention10(12)pp. 1456-1463 Europa Digital & Publishing

AIMS: Degenerative aortic valve stenosis (AVS) is independently associated with endothelial dysfunction and increased levels of circulating endothelium-derived microparticles (EMPs) as a marker of compromised endothelial integrity. The aim of this study was to investigate whether therapy for severe AVS by transcatheter aortic valve implantation (TAVI) improves endothelial function and decreases EMPs. METHODS AND RESULTS: Fifty-six patients with indication for TAVI due to symptomatic severe AVS were prospectively enrolled. Brachial wall shear stress (WSS), endothelial function and circulating microparticles (MPs) were measured before and three months following TAVI. Endothelial function was assessed as flow-mediated dilation (FMD) using ultrasound. MP subpopulations were discriminated by flow cytometry according to the expression of established surface antigens: CD31+/CD41-, CD144+ and CD62E+ as EMPs and CD41+ as platelet-derived MPs (PMPs). In patients with severe AVS, decreased brachial WSS was an independent predictor of low FMD. At three-month follow-up after TAVI, WSS and FMD increased along with decreased levels of EMPs as compared to pre TAVI. Decrease of CD31+/CD41-, CD144+ and CD62E+ EMP levels correlated with the increase of FMD. CONCLUSIONS: Therapy for AVS by TAVI was associated with improved endothelial function and integrity indicating beneficial effects of TAVI on systemic arterial function.

Emilia Stegemann, R. Sansone, B. Stegemann, M. Kelm, C. Heiss (2015)Validation of High-Resolution Ultrasound Measurements of Intima–Media Thickness of the Radial Artery for the Assessment of Structural Remodeling, In: Angiology66(6)pp. 574-577 Sage Publications

Radial artery (RA) intima–media thickness (IMT) could be used to study short- and long-term structural vascular adaptation following transradial cardiac catheterization. We aimed at assessing the reliability and reproducibility of RA-IMT measurement. Using high-resolution ultrasound, we studied RA-IMT in 17 patients, who underwent transradial catheterization via the right RA 1 to 12 months before. Radial artery intima–media thickness was measured in both arms, with the left RA as control. Repeated measurements were performed by 2 examiners and offline analyses were performed by independent blinded interpreters. Radial artery intima–media thickness was highly reliable with an interclass correlation coefficient (ICC) of 0.911 [0.870-0.939], a high examiner (ICCexaminer 0.910 [0.883-0.931]), and interpreter agreement (ICCinterpreter 0.963 [0.954-0.971]). Intima–media thickness at the radial access site was significantly increased compared with the contralateral RA (0.30 ± 0.056 vs 0.41 ± 0.055 mm, P < .00001). Radial artery intima–media thickness can be measured reliably using high-resolution ultrasound. Initial data suggest that transradial catheterization leads to long-term structural adaption processes.

Michael Gröne, Roberto Sansone, Phillip Höffken, Patrick Horn, Ana Rodriguez-Mateos, Hagen Schroeter, Malte Kelm, Christian Heiss (2019)Cocoa flavanols improve endothelial functional integrity in healthy young and elderly subjects, In: Journal of Agricultural and Food Chemistry American Chemical Society

Cocoa flavanols (CF) can improve vascular stiffness, blood pressure, and flow-mediated dilation (FMD) in healthy subjects. Endothelial microparticles (EMPs) are markers of endothelial functional integrity reflecting activation and injury. In plasma samples, we investigated whether age-dependent changes in circulating EMPs exist and whether CFs decrease EMPs in healthy humans. The concentrations of CD31+/41-, CD144+, and CD62e+-EMPs (flow-cytometry) were increased in healthy elderly (n=19) as compared to young (n=20) non-smokers. EMPs correlated with age, systolic blood pressure, and pulse wave velocity. CD31+/41- and CD62e+-EMPs inversely correlated with FMD. Following 2 weeks twice-daily CF consumption (450 mg), CD31+/41- and CD144+-EMPs decreased both in young and elderly subjects compared to CF-free control. The EMP decrease inversely correlated with FMD improvements. Cardiovascular aging is associated with increased EMPs that can be modulated by dietary flavanols along with improvements in vascular function. This indicates that flavanol consumption can improve endothelial functional integrity in healthy humans.

Emilia Stegemann, Lucas Busch, Berthold Stegemann, Thomas Lauer, Rainer Hoffmann, Christian Heiss, Malte Kelm (2015)Evaluation of a Structured Training Program for Arterial Femoral Sheath Removal after Percutaneous Arterial Catheter Procedures by Assistant Personnel, In: The American Journal of Cardiology115(7)pp. 879-883 Elsevier
Volker Schulze, Christian Meyer, Christian Eickholt, Roberto Sansone, Stefanie Keymel, Christian Heiss, Tienush Rassaf, Malte Kelm, Stephan Steiner (2018)Impact of Continuous Positive Airway Pressure on Left Ventricular Systolic Loading and Coronary Flow Reserve in Healthy Young Men, In: Heart, Lung and Circulation27(3)pp. 344-349 Elsevier

Background: Increased augmentation index (AIx) is accompanied by an elevated cardiovascular risk. A reduction of AIx is known for long-term continuous positive airway pressure (CPAP) therapy. We hypothesised that acute preload and left ventricular workload effects AIx and subendocardial viability ratio (SEVR) as a marker of coronary flow reserve. Methods: Increased augmentation index and central blood pressure parameters were measured by radial artery tonometry in 17 healthy men (32/ ± 6 years) at rest and during CPAP ventilation at pressures of 5, 10 mbar and after recovery. In a subset of seven individuals, haemodynamic parameters and autonomic function were additionally examined using combined impedance cardiography and continuous noninvasive blood pressure monitoring. Results: Continuous positive airway pressure reduced heart rate corrected (AIx@75) (-2.8 ± 8.1 [rest] to −10.7 ± 11.3 [5 mbar], p < 0.01, to −12.2 ± 10.5% [10 mbar], p < 0.01) and systolic time integral as a marker of left ventricular workload (2115 ± 231 [rest] to 1978 ± 290 [5 mbar], p = 0.02 to 1940 ± 218 [10 mbar], p < 0.01 to 2013 ± 241 mmHg/s per min [recovery], p = 0.03), while central systolic pressure did not change during CPAP. Total Peripheral Resistance Index increased reaching level of significance at 10 mbar CPAP condition (1701 ± 300 [rest] to 1850 ± 301 dyn*s*m2/cm5 [10 mbar], p = 0.04). There was a reversible increase of SEVR under CPAP conditions. Conclusions: Continuous positive airway pressure ventilation acutely reduces AIx, heart rate and left ventricular workload in healthy young men. These effects seem to be mediated by left ventricular filling pressure, workload and reflection wave. Furthermore, we found an increase of subendocardial viability ratio as an indication for a rising coronary flow reserve by CPAP.

Ana Rodriguez-Mateos, Michael Hezel, Hilal Aydin, Malte Kelm, Jon O. Lundberg, Eddie Weitzberg, Jeremy P.E. Spencer, Christian Heiss (2015)Interactions between cocoa flavanols and inorganic nitrate: Additive effects on endothelial function at achievable dietary amounts, In: FREE RADICAL BIOLOGY AND MEDICINE80pp. 121-128 ELSEVIER SCIENCE INC

Dietary intervention studies have shown that flavanols and inorganic nitrate can improve vascular function, suggesting that these two bioactives may be responsible for beneficial health effects of diets rich in fruits and vegetables. We aimed to study interactions between cocoa flavanols (CF) and nitrate, focusing on absorption, bioavailability, excretion, and efficacy to increase endothelial function. In a double-blind randomized, dose–response crossover study, flow-mediated dilation (FMD) was measured in 15 healthy subjects before and at 1, 2, 3, and 4 h after consumption of CF (1.4–10.9 mg/kg bw) or nitrate (0.1–10 mg/kg bw). To study flavanol–nitrate interactions, an additional intervention trial was performed with nitrate and CF taken in sequence at low and high amounts. FMD was measured before (0 h) and at 1 h after ingestion of nitrate (3 or 8.5 mg/kg bw) or water. Then subjects received a CF drink (2.7 or 10.9 mg/kg bw) or a micro- and macronutrient-matched CF-free drink. FMD was measured at 1, 2, and 4 h thereafter. Blood and urine samples were collected and assessed for CF and nitric oxide (NO) metabolites with HPLC and gas-phase reductive chemiluminescence. Finally, intragastric formation of NO after CF and nitrate consumption was investigated. Both CF and nitrate induced similar intake-dependent increases in FMD. Maximal values were achieved at 1 h postingestion and gradually decreased to reach baseline values at 4 h. These effects were additive at low intake levels, whereas CF did not further increase FMD after high nitrate intake. Nitrate did not affect flavanol absorption, bioavailability, or excretion, but CF enhanced nitrate-related gastric NO formation and attenuated the increase in plasma nitrite after nitrate intake. Both flavanols and inorganic nitrate can improve endothelial function in healthy subjects at intake amounts that are achievable with a normal diet. Even low dietary intake of these bioactives may exert relevant effects on endothelial function when ingested together.

U Nixdorff, S Achenbach, F Bengel, P Faggiano, S Fernández, Christian Heiss, T Mengden, FG Mureddu, E Nagel, V Puntmann, V Zamorano (2015)Imaging in Cardiovascular Prevention, In: The ESC Textbook of Preventive Cardiology Oxford University Press
Javier I. Ottaviani, Christian Heiss, Jeremy P.E. Spencer, Malte Kelm, Hagen Schroeter (2018)Recommending flavanols and procyanidins for cardiovascular health: Revisited, In: Molecular Aspects of Medicine61pp. 63-75 Elsevier

The last 8 years have seen significant developments in our understanding of dietary flavanols and procyanidins in the context of human health and nutrition. During the same time, recognition of the importance of nutrition in primary disease prevention and health maintenance has increased. In addition, the concept of dietary bioactives (food constituents that although not essential to human life and procreation, may nevertheless play an important role in disease risk reduction, primary disease prevention, and healthy aging) has been created and developed. Applying assessment criteria specific to health maintenance and primary disease prevention, we aimed at broadly evaluating and discussing currently available data on flavanols and procyanidins, with an eye towards potentially advancing the future development of dietary guidelines and public health recommendations. Novel insights and advancements as well as current gaps and shortcomings in our understanding are identified and discussed. While centered on flavanols and procyanidins, the outcomes of this review may also have broader relevance for the further development of the concept of bioactives, and any future framework for the assessment of their role in human health and nutrition.

Rodrigo P. Feliciano, Albert Boeres, Luca Massacessi, Geoffrey Istas, M. Rita Ventura, Cláudia Nunes dos Santos, Christian Heiss, Ana Rodriguez-Mateos (2016)Identification and quantification of novel cranberry-derived plasma and urinary (poly)phenols, In: Archives of Biochemistry and Biophysics599pp. 31-41 Elsevier

Cranberries are a rich source of (poly)phenols, in particular proanthocyanidins, anthocyanins, flavonols, and phenolic acids. However, little is known about their bioavailability in humans. We investigated the absorption, metabolism, and excretion of cranberry (poly)phenols in plasma and urine of healthy young men after consumption of a cranberry juice (787 mg (poly)phenols). A total of 60 cranberry-derived phenolic metabolites were identified using UPLC-Q-TOF-MS analysis with authentic standards. These included sulfates of pyrogallol, valerolactone, benzoic acids, phenylacetic acids, glucuronides of flavonols, as well as sulfates and glucuronides of cinnamic acids. The most abundant plasma metabolites were small phenolic compounds, in particular hippuric acid, catechol-O-sulfate, 2,3-dihydroxybenzoic acid, phenylacetic acid, isoferulic acid, 4-methylcatechol-O-sulfate, α-hydroxyhippuric acid, ferulic acid 4-O-sulfate, benzoic acid, 4-hydroxyphenyl acetic acid, dihydrocaffeic acid 3-O-sulfate, and vanillic acid-4-O-sulfate. Some benzoic acids, cinnamic acids, and flavonol metabolites appeared in plasma early, at 1–2 h post-consumption. Others such as phenylacetic acids, benzaldehydes, pyrogallols, catechols, hippuric and dihydrocinnamic acid derivatives appear in plasma later (Tmax 4–22 h). The 24 h urinary recovery with respect to the amount of (poly)phenols consumed was 6.2%. Our extensive description of the bioavailability of cranberry (poly)phenols lays important groundwork necessary to start understanding the fate of these compounds in humans.

Ana Rodriguez-Mateos, Natalia Toro-Funes, Tania Cifuentes-Gomez, Miriam Cortese-Krott, Christian Heiss, Jeremy P.E. Spencer (2014)Uptake and metabolism of (−)-epicatechin in endothelial cells, In: ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS559pp. 17-23 ELSEVIER SCIENCE INC

Accumulating evidence suggest that diets rich in cocoa flavanols may have beneficial effects on cardiovascular health. The major cocoa flavanol monomer, (−)-epicatechin (EC), is readily absorbed and circulates primarily as glucuronidated, sulfated, and O-methylated metabolites in human plasma. However, cellular metabolism, for example in endothelial cells, is less well defined. In the present study we detail the uptake and cellular metabolism of EC and its major in vivo metabolites, (−)-epicatechin-3′-β-d-glucuronide (E3G), (−)-epicatechin-3′-sulfate (E3S), 3′-O-methyl-(−)-epicatechin-5-sulfate (3ME5S), and 3′-O-methyl-(−)-epicatechin-7-sulfate (3ME7S) in human endothelial (HUVEC), liver (HepG2) and intestinal epithelial cells (Caco-2 monolayer). Our results indicate that EC associates with HUVECs, leading to its intracellular metabolism to 3ME7G and 3ME7S. In contrast, none of the metabolites were taken up by the cells. The metabolic rate and pattern of metabolism in HUVECs was similar to that observed in HepG2 cells, whilst in Caco-2 cells EC was metabolized to E3G, 3ME5G, 3ME7G, 4ME5G, 4ME7G and 3ME7S. Our data support the notion that endothelial cells may contribute significantly to EC metabolism. However, major human circulating metabolites are not accounted for in these model systems underscoring that caution should be taken when drawing conclusions on in vivo flavanol metabolism from in vitro experiments.

T Lauer, M Kelm, Christian Heiss (2012)Fluß-mediierte Dilatation, In: Nicht-invasive Diagnostik angiologischer Krankheitsbilder ABW Wissenschaftsverlagsgesellschaft
Marc W. Merx, Patrick Horn, Gülsüm Erkilet, Verena Veulemans, Patric Kröpil, Leon Schurgers, Tobias Zeus, Christian Heiss, Malte Kelm, Ralf Westenfeld (2016)Microparticle-Induced Coagulation Relates to Coronary Artery Atherosclerosis in Severe Aortic Valve Stenosis, In: PLOS ONE11(3)e0151499 Public Library of Science

Background Circulating microparticles (MPs) derived from endothelial cells and blood cells bear procoagulant activity and promote thrombin generation. Thrombin exerts proinflammatory effects mediating the progression of atherosclerosis. Aortic valve stenosis may represent an atherosclerosis-like process involving both the aortic valve and the vascular system. The aim of this study was to investigate whether MP-induced thrombin generation is related to coronary atherosclerosis and aortic valve calcification. Methods In a cross-sectional study of 55 patients with severe aortic valve stenosis, we assessed the coronary calcification score (CAC) as indicator of total coronary atherosclerosis burden, and aortic valve calcification (AVC) by computed tomography. Thrombin-antithrombin complex (TATc) levels were measured as a marker for thrombin formation. Circulating MPs were characterized by flow cytometry according to the expression of established surface antigens and by measuring MP-induced thrombin generation. Results Patients with CAC score below the median were classified as patients with low CAC, patients with CAC Score above the median as high CAC. In patients with high CAC compared to patients with low CAC we detected higher levels of TATc, platelet-derived MPs (PMPs), endothelial-derived MPs (EMPs) and MP-induced thrombin generation. Increased level of PMPs and MP-induced thrombin generation were independent predictors for the severity of CAC. In contrast, AVC Score did not differ between patients with high and low CAC and did neither correlate with MPs levels nor with MP-induced thrombin generation. Conclusion In patients with severe aortic valve stenosis MP-induced thrombin generation was independently associated with the severity of CAC but not AVC indicating different pathomechanisms involved in coronary artery and aortic valve calcification.

T Rassaf, R Westenfeld, J Balzer, T Lauer, M Merx, J Floege, S Steiner, C Heiss, M Kelm, C Meyer (2010)Modulation of peripheral chemoreflex by neurohumoral adaptations after kidney transplantation, In: European Journal of Medical Research15(Sup 2)pp. pp83-87 biomedcentral

Background Peripheral chemoreceptors residing predominantly in the carotid body monitor changes in arterial blood oxygen and are mechanistically linked to the cardiorespiratory control by the autonomic nervous system. Enhanced sympathetic activation is common in end-stage renal disease and kidney transplantation has been shown to improve cardiorespiratory reflex measures of autonomic function. Objective The aim of the present study was to test whether improvement in renal function following kidney transplantation is related to an improvement in chemosensory function. Methods and Results We compared hyperoxic chemoreflex sensitivity (CHRS) in patients after renal transplantation (RTX) to that in patients on maintenance hemodialysis (HD), and that of age- and gender-matched healthy controls. In addition, we investigated the impact of common confounding factors including pharmacological neurohumoral modulation and diabetes mellitus. The difference in the R-R intervals divided by the difference in the oxygen pressures before and after deactivation of the chemoreceptors by 5-min inhalation of 7 L oxygen was calculated as the hyperoxic CHRS. Autonomic activity was characterized by 24-h time-domain heart rate variability (HRV) parameters. CHRS was improved in RTX patients as compared to HD patients being related to HRV. CHRS was related to the concomitant presence of diabetes and medication with cyclosporine. Conclusion Our findings indicate that chemosensory activity following kidney transplantation is related to cardiac autonomic control, but functional testing might only be useful to characterize the time course and extent of sympathetic activation in selected patients due to existing co-morbidities and immunosuppressive medication in this population.

Verena Veulemans, Shazia Afzal, Paul Ledwig, Christian Heiss, Lucas Busch, Roberto Sansone, Dagmar B. Soetemann, Oliver Maier, Laura Kleinebrecht, Malte Kelm, Tobias Zeus, Katharina Hellhammer (2018)Stent fractures after common femoral artery bail-out stenting due to suture device failure in TAVR, In: Vasa47(5)pp. 393-401 Hogrefe

Background: Vascular access site-related complications are frequent in the context of transfemoral transcatheter aortic valve replacement (TAVR). The implantation of a covered stent graft is an effective treatment option for bleeding control. However, the external iliac and common femoral arteries are exposed to flexion of the hip joint. Therefore, stent compression and stent/strut fractures may occur, facilitating stent occlusion. Patients and methods: In all 389 patients who received transfemoral TAVR from 2013–2015 at the Düsseldorf Heart Centre, we monitored the management of vascular access site-related complications. Our analyses focused on immediate technical success and bleeding control, primary patency, and the occurrence of stent/strut fractures after six to 12 months of follow-up. Results: Vascular access site-related complications occurred in 13 % (n = 51), whereof in 10 patients, the bleeding was successfully managed by prolonged compression. In 40 out of 51 patients, a covered stent graft was implanted in the common femoral artery, leading to 100 % immediate bleeding control. After a mean follow-up of 334 ± 188 days, 28 stents out of 29 patients with completed follow-up (excluding e. g. death) were without flow-limiting stenosis (primary patency 97 %) or relevant stent compression (diameter pre/post 8.6/8.1 mm, p = 0.048, late lumen loss 1.1 ± 0.2 mm, mean flow velocity 92 ± 34 cm/s). In four asymptomatic patients, stent/strut fractures were detected (14 %) without flow-limiting stenosis. Conclusions: The implantation of a covered stent graft is highly effective and safe to control vascular access site-related complications after TAVR. Stent/strut fractures in the flexible segment of the common femoral artery may occur, as consequently verified by X-ray visualization, but show no impairment on flow or clinical parameters after six to 12 months.

Christian Heiss (2015)"Yes, FMD should be measured in the lower extremity of PAD patients!", In: Journal of the American Heart Association Wiley Open Access
Christian Heiss, M Kelm, T Lauer (2012)Bestimmung der Intima-Media Dicke, In: Nicht invasive Diagnostik angiologischer Krankheitsbilder ABW Wissenschaftsverlagsgesellschaft
Roberto Sansone, Emilia Stegemann, Göksen Özaslan, Dominik Schuler, Margarete Lukosz, Ana Rodriguez-Mateos, Thomas Lauer, Ralf Westenfeld, Malte Kelm, Christian Heiss (2014)Early and late response-to-injury in patients undergoing transradial coronary angiography: arterial remodeling in smokers, In: American Journal of Cardiovascular Disease4(2)pp. pp47-57 e-Century Publishing

Objectives: To investigate the effect of smoking on vascular response to transradial coronary angiography (TCA). Background: Cigarette smoking is the most important modifiable cardiovascular risk factor associated with endothelial dysfunction. Methods: Radial artery flow-mediated vasodilation (RA-FMD), local stiffness (fractional diameter change), intima-media thickness (IMT), luminal and external arterial diameter were measured in 40 current smokers (CS) and former smokers (FS) at 6-14 months at the site of previous TCA and contralateral control artery. Vascular regenerative capacity was studied as chemotactic cell migration in vitro and ex vivo (n=10) and the time course of endothelial functional recovery following RA-FMD up to 72 h after TCA (n=10). Results: At 10 ± 3 months after TCA, subjects exhibited significant local stiffening and increased IMT as compared to the control arm. These late structural changes were significantly more pronounced in CS as compared to FS. IMT thickening correlated with packyears, number of daily cigarettes, and inversely with RA-FMD. Nitric oxide synthase (NOS)-dependent chemotaxis of CS’ circulating angiogenic cells was impaired. Ex vivo incubation of endothelial cells with CS’ plasma inhibited NOS-dependent endothelial wound closure and chemotaxis. In vivo, TCA acutely decreased RA-FMD. At 24 h, RA-FMD had recovered in FS but remained impaired at 24 h and only recovered at 48 h in CS. Conclusion: In active smokers, transradial coronary angiography is associated with delayed early recovery from transient endothelial dysfunction, decreased NOS-dependent vascular regeneration, and late arterial remodeling pointing towards potential harmful effects of transradial coronary angiography on vascular function in distinct subsets of patients.

Christian Heiss, Christian Meyer, Matthias Totzeck, Ulrike B. Hendgen-Cotta, Yvonne Heinen, Peter Luedike, Stefanie Keymel, Nassim Ayoub, Jon O. Lundberg, Eddie Weitzberg, Malte Kelm, Tienush Rassaf (2012)Dietary inorganic nitrate mobilizes circulating angiogenic cells, In: FREE RADICAL BIOLOGY AND MEDICINE52(9)pp. 1767-1772 ELSEVIER SCIENCE INC

Nitric oxide (NO) was implicated in the regulation of mobilization and function of circulating angiogenic cells (CACs). The supposedly inert anion nitrate, abundant in vegetables, can be stepwise reduced in vivo to form nitrite, and consecutively NO, representing an alternative to endogenous NO formation by NO synthases. This study investigated whether inorganic dietary nitrate influences mobilization of CACs. In a randomized double-blind fashion, healthy volunteers ingested 150 ml water with 0.15 mmol/kg (12.7 mg/kg) of sodium nitrate, an amount corresponding to 100–300 g of a nitrate-rich vegetable, or water alone as control. Mobilization of CACs was determined by the number of CD34+/KDR+ and CD133+/KDR+ cells using flow cytometry and the mobilization markers stem cell factor (SCF) and stromal cell-derived factor-1a (SDF-1α) were determined in plasma via ELISA. Nitrite and nitrate were measured using high-performance liquid chromatography and reductive gas-phase chemiluminescence, respectively. NOS-dependent vasodilation was measured as flow-mediated vasodilation. Further mechanistic studies were performed in mice after intravenous application of nitrite together with an NO scavenger to identify the role of nitrite and NO in CAC mobilization. Nitrate ingestion led to a rise in plasma nitrite together with an acute increase in CD34+/KDR+ and CD133+/KDR+-CACs along with increased NOS-dependent vasodilation. This was paralleled by an increase in SCF and SDF-1α and the maximal increase in plasma nitrite correlated with CD133+/KDR+-CACs (r = 0.73, P = 0.016). In mice, nitrate given per gavage and direct intravenous injection of nitrite led to CAC mobilization, which was abolished by the NO scavenger cPTIO, suggesting that nitrite mediated its effect via formation of NO. Dietary inorganic nitrate acutely mobilizes CACs via serial reduction to nitrite and NO. The nitrate–nitrite–NO pathway could offer a novel nutritional approach for regulation of vascular regenerative processes.

E. Wood, S. Hein, C. Heiss, C. Williams, Ana Rodriguez-Mateos (2019)Blueberries and cardiovascular disease prevention, In: Food and Function10(12)pp. 7621-7633 Royal Society of Chemistry

Blueberries are a rich source of (poly)phenols, particularly anthocyanins. Epidemiological studies indicate that anthocyanin-rich foods including blueberries are associated with a reduction in the risk of cardiovascular disease. These observational findings are supported by a number of randomized-controlled trials showing improvements in biomarkers of cardiovascular disease risk. The beneficial effects of blueberry (poly)phenols are particularly clear when measuring flow-mediated dilation over various timeframes and study populations. However, other outcomes are less clear, such as effects on blood pressure, arterial stiffness and blood lipid profile. This may be due to the heterogeneity existing in study designs, such as duration of the intervention, and the health status of participants. Longer-term RCTs using gold standard methods in relevant populations which can be translated to the general public are needed to clarify and strengthen the evidence available. While circulating phenolic blueberry metabolites have been linked with improvements in vascular function, the biological activities and mechanisms of action of individual metabolites and their interaction in vivo are still unknown. Evaluating the bioactivities of metabolites alone and together, and analysing their structure-activity relationship in well-designed and physiologically relevant experimental and human studies are needed to understand the mechanisms of how these metabolites affect vascular function.

Jill Belch, Anita Carlizza, Patrick H. Carpentier, Joel Constans, Faisel Khan, Jean-Claude Wautrecht, Adriana Visona, Christian Heiss, Marianne Brodeman, Zsolt Pécsvárady, Karel Roztocil, Mary-Paula Colgan, Dragan Vasic, Anders Gottsäter, Beatrice Amann-Vesti, Ali Chraim, Pavel Poredoš, Dan-Mircea Olinic, Juraj Madaric, Sigrid Nikol, Ariane L. Herrick, Muriel Sprynger, Peter Klein-Weigel, Franz Hafner, Daniel Staub, Zan Zeman (2017)ESVM guidelines – the diagnosis and management of Raynaud’s phenomenon, In: Vasa46(6)pp. 413-423 Hogrefe

Regarding the clinical diagnosis of Raynaud’s phenomenon and its associated conditions, investigations and treatment are substantial, and yet no international consensus has been published regarding the medical management of patients presenting with this condition. Most knowledge on this topic derives from epidemiological surveys and observational studies; few randomized studies are available, almost all relating to drug treatment, and thus these guidelines were developed as an expert consensus document to aid in the diagnosis and management of Raynaud’s phenomenon. This consensus document starts with a clarification about the definition and terminology of Raynaud’s phenomenon and covers the differential and aetiological diagnoses as well as the symptomatic treatment.

Patricia I. Oteiza, Christian Heiss (2018)Introduction to special issue on Polyphenols and Health, In: Archives of Biochemistry and Biophysics652pp. 1-2 Elsevier

The understanding of the beneficial effects of plant bioactives on human health is of critical interest considering the already observed and proven benefits for some of them, i.e. fiber and control of glycemia, stanols mitigating hypercholesterolemia. In the field of polyphenols, and as discussed in the introductory review [1], research has grown exponentially in the last 25 years, at a faster rate than for other bioactives. Although there is a significant lack of information on major aspects of the relevance of dietary polyphenols on human health, the field has advanced significantly. Thus, there is considerably more information on the absorption, distribution, metabolism, and excretion (ADME) of polyphenols in healthy humans [2]. In particular, it is important to consider that humans can have major differences in metabolizing capacity given individual differences in intestinal microbiota and in the genes involved in ADME [2,3]. Characterization of polyphenol metabolism in different species (e.g. humans [2,3] and rats [4] is relevant for the evaluation of how the extensive experimental research originated in rodents can be extrapolated to the actions of individual polyphenols in humans.

Andrea Schanz, Dunja M. Baston-Büst, Christian Heiss, Ines M. Beyer, Jan S. Krüssel, Alexandra P. Hess (2014)Interferon stimulated gene 15 expression at the human embryo−maternal interface, In: Archives of Gynecology and Obstetrics290(4)pp. 783-789 Springer Berlin Heidelberg

Purpose In early pregnancy the dialogue between maternal endometrium and embryo is a key process in establishing a receptive decidua and placental network. Decidual ISG15 induction is thought to promote pregnancy maintenance and development. ISG15 is involved in RNA splicing, cytoskeletal organization, stress response and further intracellular processes. Methods ISG15 expression was examined immunohistologically in paraffin-embedded human placental and decidual tissue samples of all pregnancy trimesters on adjacent sections (first trimester n = 5, second n = 5, third n = 3). Samples were processed using a protocol applying a rabbit polyclonal ISG15 antibody. A mouse monoclonal cytokeratin seven antibody was utilized to identify the different placental departments and decidual glands. Staining results and anatomical features were evaluated blindly with strict rating criteria. Results ISG15 expression was identified in first and second trimester tissue samples. ISG15 localized especially to the extravillous cytotrophoblasts in the maternal wall and in maternal blood vessel. Expression was detected in cytotrophoblast progenitor cells in the placental villi and the cell column with a maximum in the first trimester. The syncytial layer stained positive in first and second trimester samples. Third trimester samples showed no expression of ISG15 at all. Conclusions ISG15 abundance in the human placenta is an interesting finding, with implications for placental development, fetal growth and potential defense mechanism against infections. The maximal expression of ISG15 in the first and second trimester of pregnancy suggests that ISG function is needed when placental and embryo development is enormous and embryo susceptibility to external influences is high.

Eva S. Kehmeier, Wolfgang Lepper, Martina Kropp, Christian Heiss, Ulrike Hendgen-Cotta, Jan Balzer, Mirja Neizel, Christian Meyer, Marc W. Merx, P Verde, Christian Ohmann, Gerd Heusch, Malte Kelm, Tienush Rassaf (2012)TNF-α, myocardial perfusion and function in patients with ST-segment elevation myocardial infarction and primary percutaneous coronary intervention, In: Clinical Research in Cardiology101(10)pp. 815-827 Springer Nature

Aims To characterize the time course of tumor necrosis factor-α (TNF-α) serum levels along with myocardial perfusion and contractile function in patients with ST-segment elevation myocardial infarction (STEMI) and successful primary percutaneous coronary intervention (PCI). Methods Serum levels of TNF-α, interleukin 6 (IL-6), and C-reactive protein (CRP) were measured in 42 patients with STEMI before, one and 6 days after successful PCI. Myocardial perfusion was assessed by contrast-enhanced echocardiography (ceEcho), contractile function by unenhanced two-dimensional (2DE) and real-time three-dimensional echocardiography. In a subset of 18 patients, infarct size was quantified by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) on day six. Results TNF-α serum levels were in the upper normal range within the first 12 h from symptom onset and increased continuously until day six, while IL-6 and CRP increased subsequently with a peak on day one after STEMI. Serum TNF-α on day one after PCI correlated with perfusion defects, wall motion abnormalities, and infarct size (ceEcho: r = 0.52, p = 0.005; 2DE: r = 0.56, p = 0.002; LGE-CMR: r = 0.83–0.86; p < 0.0001). Using multiple regression linear analysis, infarct size on day six was predicted by serum TNF-α 1 day after PCI (p = 0.006, adjusted R 2 0.638). Conclusion Our data reflect the clinical significance of early TNF-α elevation in patients with STEMI and primary PCI (Controlled Clinical Trials number, NCT00529607).

Christian Heiss, Alex Pitcher, Jill J F Belch, Marco De Carlo, Holger Reinecke, Iris Baumgartner, Lucia Mazzolai, Victor Aboyans (2020)The year in cardiology: aorta and peripheral circulation, In: European Heart Journal41(4)pp. 501-508b Oxford University Press

Similar to previous years, 1–3 the current article reviews groundbreaking science published 2019 in the area of aortic and peripheral arterial diseases (PAD) as well as venous thromboembolic disease (VTE) that will affect our daily clinical practice. With the growing recognition of PAD, it will be necessary to consolidate imprecisions in terminology. Many are used to the acronym PAD for atherosclerotic disease of the lower extremity arteries. Others have used the same acronym to qualify atherosclerotic disease of the lower extremity arteries and carotid arteries. In the current article and in line with the European Society of Cardiology (ESC) guidelines, 4 we have stringently used the specific terms lower extremity arterial disease (LEAD) and reserved PAD as the umbrella term encompassing all arterial diseases other than aorta and coronaries

J Balzer, T Lauer, M Preik, Christian Heiss, BE Strauer, M Kelm (2005)Contributions of microvascular disease to abnormal endothelium-dependent arterial dilation in conduit arteries of hypertensive patients, In: Cardiovisionen 2004 Verlag Ferdinand Schöningh
Dominik Schuler, Roberto Sansone, Christopher Nicolaus, Malte Kelm, Christian Heiss (2018)Repetitive remote occlusion (RRO) stimulates eNOS-dependent blood flow and collateral expansion in hindlimb ischemia, In: Free Radical Biology and Medicine129pp. 520-531 Elsevier

Objective: Collateral expansion is an important compensatory mechanism to alleviate tissue ischemia after arterial occlusion. We investigated the efficacy and mechanisms of temporary remote hindlimb occlusion to stimulate contralateral blood flow and collateral expansion after hindlimb ischemia in mice and evaluated translation to peripheral artery disease in humans. Methods and Results: We induced unilateral hindlimb ischemia via femoral artery excision in mice. We studied central hemodynamics, blood flow, and perfusion of the ischemic hindlimb during single and repetitive remote occlusion (RRO) of the contralateral non-ischemic hindlimb with a pressurized cuff. Similar experiments were performed in patients with unilateral peripheral artery disease (PAD). Contralateral occlusion of the non-ischemic hindlimb led to an acute increase in blood flow to the ischemic hindlimb without affecting central blood pressure and cardiac output. The increase in blood flow was sustained even after deflation of the pressure cuff. RRO over 12 days (8/day, each 5 min) led to significantly increased arterial inflow, lumen expansion of collateral arteries, and increased perfusion of the chronically ischemic hindlimb as compared to control. In NOS3-/- and after inhibition of NOS (L-NAME), and NO (ODQ), the acute and chronic effects of contralateral occlusion were abrogated and stimulation of guanylyl cyclase with cinaciguate exhibited a similar response as RRO and was not additive. Pilot studies in PAD patients demonstrated that contralateral occlusion increased arterial inflow to ischemic limbs and improved walking distance. Conclusions: Repetitive remote contralateral occlusion stimulates arterial inflow, perfusion, and functional collateral expansion in chronic hindlimb ischemia via an eNOS-dependent mechanism underscoring the potential of remote occlusion as a novel treatment option in peripheral artery disease.

A. Schanz, D. Baston-Bust, J.S. Krussel, C. Heiss, W. Janni, A.P. Hess (2011)CXCR7 and syndecan-4 are potential receptors for CXCL12 in human cytotrophoblasts, In: Journal of Reproductive Immunology89(1)pp. 18-25 Elsevier

The placenta forms the interface between the mother and the fetus. During placental development cytotrophoblasts differentiate to form the syncytium or to invade the decidual wall to breach maternal vessels and establish the blood flow in the intervillous space. This process is still not well understood but it is proposed that chemokines and their receptors are involved in guiding cytotrophoblasts to the decidua and maternal vessels as well as attracting immunocompetent cells to the implantation site. CXCL12 is a chemokine expressed by cytotrophoblasts and is involved in cytotrophoblast invasion, differentiation and survival. One of its receptors, CXCR4, has been detected on cytotrophoblasts. Recent data show that CXCR7 and syndecan-4 might partially mediate CXCL12 function in other cell types. In this study, we examined CXCR7 and syndecan-4 expression at the maternal–fetal interface via immmunolocalization in placental tissue sections and in isolated cytotrophoblasts. We further used immunoblot analyses to confirm the data. We were able to show that cytotrophoblasts express both receptors and that upregulation occurs during the differentiation process of cytotrophoblasts towards the invasive phenotype. On a functional level CXCR7 seems not to be involved in JAR cell chemotaxis, suggesting a different function of this receptor. In conclusion, we propose that CXCL12 binds to CXCR4, but also to CXCR7 and syndecan-4. These three receptors could mediate different functions of CXCL12, such as cell migration, directed invasion, proliferation and survival. The latter molecules might also be involved in the development of placental pathologies, such as preeclampsia or choriocarcinoma growth.

Christian Heiss, A. Schanz, N. Amabile, S. Jahn, Q. Chen, M. L. Wong, T. Rassaf, Y. Heinen, M. Cortese-Krott, W. Grossman, Y. Yeghiazarians, M. L. Springer (2010)Nitric Oxide Synthase Expression and Functional Response to Nitric Oxide Are Both Important Modulators of Circulating Angiogenic Cell Response to Angiogenic Stimuli, In: Arteriosclerosis, Thrombosis, and Vascular Biology30(11)pp. 2212-2218

Objective Circulating angiogenic cells (CACs), also termed endothelial progenitor cells, play an integral role in vascular repair and are functionally impaired in coronary artery disease (CAD). The role of nitric oxide (NO) in CAC function is poorly understood. We hypothesized that CAC migration toward angiogenic signals is modulated by both NO synthase (NOS) expression and functional response to NO. Methods and Results Similar to endothelial cells, CAC chemotaxis to VEGF was blocked by inhibition of NOS, phosphoinositide-3 kinase, or guanylyl cyclase, or by treatment with an NO scavenger. Addition of a NO donor (SNAP) and the NOS-substrate L-arginine increased random cell migration (chemokinesis) and enhanced VEGF-dependent chemotaxis. Healthy CACs expressed eNOS, but eNOS was not detected in CAD patient CACs. Both chemokinesis and chemotaxis to VEGF of patient CACs were decreased compared to healthy CACs, but were restored to healthy values by SNAP. In parallel, CAD patients exhibited lower flow-mediated vasodilation and plasma NO source nitrite than young healthy subjects, indicating endothelial dysfunction with reduced NO bioavailability. Conclusions NOS activity is required for CAC chemotaxis. In CAD patients, impairment of NOS expression and NO bioavailability, rather than response to NO, may contribute to CAC dysfunction and limit their regenerative capacity.

STEFANIE KEYMEL, JULIA SICHWARDT, JAN BALZER, EMILIA STEGEMANN, TIENUSH RASSAF, PETRA KLEINBONGARD, MALTE KELM, Christian Heiss, Thomas LAUER (2010)Characterization of the Non-Invasive Assessment of the Cutaneous Microcirculation by Laser Doppler Perfusion Scanner, In: Microcirculation17pp. pp358-366 Wiley

Objective:  Microcirculatory dysfunction contributes to morbidity and mortality in vascular diseases. Here, we aimed at establishing a sensitive and valid method to measure microvascular reactivity during post‐occlusive reactive hyperemia (PORH) using scanning laser Doppler perfusion imaging (LDPI) of the forearm. Methods:  In a first series, LDPI was methodologically evaluated on the volar forearm of healthy volunteers (n = 10) before and after one to five minutes of upper arm occlusion. In a second series, readings were performed in 20 healthy subjects and 20 patients with coronary artery disease (CAD). Results:  Three minutes of forearm occlusion were sufficient to induce maximal vasodilation during PORH as indicated by maximal increase in perfusion unit (PU) amplitude that did not further increase after five‐minute occlusion. Five‐minute occlusion led to a significant prolongation of PORH with greater area under curve (AUC) suggesting longer lasting vasodilation of microvessels. The five‐minute occlusion was associated with lower variability as compared with three minutes (intraindividual variability: 9–17% vs. 12–21%; interindividual variability: 13–24% vs. 14–26%). CAD patients exhibited significantly reduced amplitude (105 ± 49 vs. 164 ± 35 PU; p 

Christian Heiss, Roberto Sansone, Hakima Karimi, Moritz Krabbe, Dominik Schuler, Ana Rodriguez-Mateos, Thomas Kraemer, Miriam Margherita Cortese-Krott, Gunter G. C. Kuhnle, Jeremy P. E. Spencer, Hagen Schroeter, Marc W. Merx, Malte Kelm (2015)Impact of cocoa flavanol intake on age-dependent vascular stiffness in healthy men: a randomized, controlled, double-masked trial, In: AGE3756 Springer

Increased vascular stiffness, endothelial dysfunction, and isolated systolic hypertension are hallmarks of vascular aging. Regular cocoa flavanol (CF) intake can improve vascular function in healthy young and elderly at-risk individuals. However, the mechanisms underlying CF bioactivity remain largely unknown. We investigated the effects of CF intake on cardiovascular function in healthy young and elderly individuals without history, signs, or symptoms of cardiovascular disease by applying particular focus on functional endpoints relevant to cardiovascular aging. In a randomized, controlled, double-masked, parallel-group dietary intervention trial, 22 young (

Patrick Horn, Theodor Baars, Kahlert Philipp, Christian Heiss, Ralf Westenfeld, Malte Kelm, Raimund Erbel, Gerd Heusch,, Petra Kleinbongard (2015)Release of Intracoronary Microparticles during Stent Implantation into Stable Atherosclerotic Lesions under Protection with an Aspiration Device, In: PloS ONE10(4)e0124904 Public Library of Science

Objective Stent implantation into atherosclerotic coronary vessels impacts on downstream microvascular function and induces the release of particulate debris and soluble substances, which differs qualitatively and quantitatively between native right coronary arteries (RCAs) and saphenous vein grafts on right coronary arteries (SVG-RCAs). We have now quantified the release of microparticles (MPs) during stent implantation into stable atherosclerotic lesions and compared the release between RCAs and SVG-RCAs. Methods In symptomatic, male patients with stable angina and a stenosis in their RCA or SVG-RCA, respectively (n = 14/14), plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation with a distal occlusion/aspiration device and divided into particulate debris and plasma. Particulate debris was weighed. Platelet-derived MPs (PMPs) were distinguished by flow cytometry as CD41+, endothelium-derived MPs (EMPs) as CD144+, CD62E+ and CD31+/CD41-, leukocyte-derived MPs as CD45+, and erythrocyte-derived MPs as CD235+. Results In patients with comparable plaque volume and composition in RCAs and SVG-RCAs, intracoronary PMPs and EMPs were increased after stent implantation into their RCAs and SVG-RCAs (CD41+: 2729.6±645.6 vs. 4208.7±679.4 and 2355.9±503.9 vs. 3285.8±733.2 nr/µL; CD144+: 451.5±87.9 vs. 861.7±147.0 and 444.6±74.8 vs. 726.5±136.4 nr/µL; CD62E+: 1404.1±247.7 vs. 1844.3±378.6 and 1084.6±211.0 vs. 1783.8±384.3 nr/µL, P

Andrea Schanz, Virginia D. Winn, Susan J. Fisher, Marion Blumenstein, Christian Heiss, Alexandra P. Hess, Jan S. Kruessel, Michael Mcmaster, Robyn A. North (2011)Pre-eclampsia is associated with elevated CXCL12 levels in placental syncytiotrophoblasts and maternal blood, In: European Journal of Obstetrics and Gynecology and Reproductive Biology157(1)pp. 32-37 ELSEVIER IRELAND LTD

Objectives Placental derived vasculogenic/angiogenic substances in maternal blood are dysregulated in pre-eclampsia. We hypothesized that CXCL12, a chemokine with vasculogenic actions, is amongst such molecules. Study design CXCL12, CXCL16, CXCR4, and CXCR6 immunolocalization in placental tissue was analyzed in pre-eclampsia (n = 8) in comparison to controls (n = 8). CXCL12, measured by ELISA in blood, in women diagnosed with pre-eclampsia (n = 14) and prior to the development of pre-eclampsia (at 20 weeks’ gestation, n = 20) was compared with CXCL12 concentrations in gestation-matched, healthy control subjects (n = 34). Results In placental tissue, syncytiotrophoblast staining for CXCL12 was increased in pre-eclampsia. Maternal serum CXCL12 was increased in pre-eclampsia [2000 (SD 402) vs 1484 (SD 261) pg/ml, P = 0.01] but not in plasma obtained at 20 weeks of gestation prior to the onset of pre-eclampsia [1183 (SD 336) vs 1036 (SD 144) pg/ml, P = 0.09]. Conclusion Our data suggest that the syncytiotrophoblast contributes to a pre-eclampsia-associated increase in CXCL12 levels in maternal blood. These findings support the hypothesis that an imbalance of angiogenic factors contributes to the pathogenesis of pre-eclampsia.

Ana Rodriguez-Mateos, Tania Cifuentes-Gomez, Isidro Gonzalez-Salvador, Javier I. Ottaviani, Hagen Schroeter, Malte Kelm, Christian Heiss, Jeremy P. E. Spencer (2015)Influence of age on the absorption, metabolism, and excretion of cocoa flavanols in healthy subjects, In: Molecular Nutrition & Food Research59(8)pp. 1504-1512 Wiley

Scope An understanding of the pharmacokinetics of structurally related (−)‐epicatechin metabolites (SREM) is a prerequisite for considering cocoa flavanols (CF) in the context of dietary recommendations. The objective of this study was to compare the absorption, metabolism, and excretion of SREM in healthy young and elderly Caucasian men. Methods and results Intraindividual variability of SREM was assessed in seven young subjects, after consuming 10.7 mg CF/kg body weight (BW) on two occasions separated by 1 week. The effect of age on flavanols ADME was assessed in 20 young (18–35 years) and 20 elderly (65–80 years) healthy male subjects receiving 5.3 and 10.7 mg total CF/kg BW or 1 g of acetaminophen as a control to compare differences in Phase II metabolism on three days separated by 1 week of wash‐out. Blood and urine samples were collected for 24‐h post consumption. The intraindividual variation, measured as CV(%) with respect to the area‐under‐the‐curve of the concentration over time (AUC(0‐6h)) of SREM, was 16%, while the interindividual variation in AUC(0‐6h), was 38%, comparable to acetaminophen (39%). The AUC(0‐6h) and the 24‐h excretion of total SREM was not significantly different between young and elderly subjects. At the high intake amount, the AUC(0‐6h) of (−)‐epicatechin‐3′‐β‐D‐glucuronide was greater in elderly subjects, whereas the AUC(0‐6h) of 3′‐O‐methyl‐(−)‐epicatechin‐5‐sulfate and 3′‐O‐methyl‐(−)‐epicatechin‐7‐sulfate as well as the 24‐h urinary excretion of γ‐valerolactone metabolites were lower in the elderly. Conclusion Cocoa flavanols are absorbed, metabolized, and excreted in healthy young and elderly subjects with relatively small differences between the two groups.

Roberto Sansone, Beate Stanske, Stefanie Keymel, Dominik Schuler, Patrick Horn, Diyar Saeed, Udo Boeken, Ralf Westenfeld, Artur Lichtenberg, Malte Kelm, Christian Heiss (2015)Macrovascular and microvascular function after implantation of left ventricular assist devices in end-stage heart failure: Role of microparticles, In: The Journal of Heart and Lung Transplantation34(7)pp. 921-932 Elsevier
T. Driesen, D. Schuler, R. Schmetter, C. Heiss, M. Kelm, J. W. Fischer, T. Freudenberger (2015)A systematic approach to assess locoregional differences in angiogenesis, In: Histochemistry and Cell Biology145(2)pp. 213-225 Springer

Skeletal muscle tissue differs with regard to the abundance of glycolytic and oxidative fiber types. In this context, capillary density has been described to be higher in muscle tissue with more oxidative metabolism as compared to that one with more glycolytic metabolism, and the highest abundance of capillaries has been found in boneward-oriented moieties of skeletal muscle tissue. Importantly, capillary formation is often analyzed as a measure for angiogenesis, a process that describes neo-vessel formation emanating from preexisting vessels, occurring, i.e., after arterial occlusion. However, a standardized way for investigation of calf muscle capillarization after surgically induced unilateral hind limb ischemia in mice, especially considering these locoregional differences, has not been provided so far. In this manuscript, a novel, methodical approach for reliable analysis of capillary density was established using anatomic–morphological reference points, and a software-assisted way of capillary density analysis is described. Thus, the systematic approach provided conscientiously considers intra-layer differences in capillary formation and therefore guarantees for a robust, standardized analysis of capillary density as a measure for angiogenesis. The significance of the methodology is further supported by the observation that capillary density in the calf muscle layers analyzed negatively correlates with distal lower limb perfusion measured in vivo.

CHRISTIAN MEYER, GEERT MORREN, JENS MUEHLSTEFF, CHRISTIAN HEISS, THOMAS LAUER, PATRICK SCHAUERTE, TIENUSH RASSAF, HELMUT PURERFELLNER, MALTE KELM (2011)Predicting Neurally Mediated Syncope Based on Pulse Arrival Time: Algorithm Development and Preliminary Results, In: Journal of Cardiovascular Electrophysiology22(9)pp. 1042-1048 Wiley

Prediction of Neurally Mediated Syncope. Background: Neurally mediated syncope (NMS) is a common disorder that is triggered by orthostatic stress. The circulatory adjustments to orthostatic stress occur just prior to a sudden loss of consciousness. NMS prediction would protect patients from falls or accidents. Methods and Results: Based on simultaneously recorded heart rate (HR) and pulse wave during 70° head‐up tilt (HUT) table testing we investigated a syncope warning system. In 14 patients with a history of suspected NMS we tested 2 algorithms based on HR and/or pulse arrival time (PAT). When the cumulative risk exceeded the threshold, which was calculated during the first 2 minutes following the posture change to upright position, a syncope prediction alarm was triggered. All syncopes (n = 7) were detected more than 16 seconds before the onset of dizziness or unconsciousness by using a prediction alarm based on HR and PAT (syncope prediction algorithm 2). No false alarm was generated in patients with negative HUT (n = 7). Syncope prediction was improved by detecting the slope of HR changes as compared with monitoring PAT changes alone (syncope prediction algorithm 1). The duration between the prediction alarm and the occurrence of syncope was 99 ± 108 seconds. Conclusion: Predicting NMS is feasible by monitoring HR and the onset of the pulse wave at the periphery. This approach might improve NMS management. 

Christian Heiss, Sarah Jahn, Melanie Taylor, Wendy May Real, Franca S. Angeli, Maelene L. Wong, Nicolas Amabile, Megha Prasad, Tienush Rassaf, Javier I. Ottaviani, Shirley Mihardja, Carl L. Keen, Matthew L. Springer, Andrew Boyle, William Grossman, Stanton A. Glantz, Hagen Schroeter, Yerem Yeghiazarians (2010)Improvement of Endothelial Function With Dietary Flavanols Is Associated With Mobilization of Circulating Angiogenic Cells in Patients With Coronary Artery Disease, In: Journal of the American College of Cardiology56(3)pp. 218-224 Elsevier

Objectives In patients with coronary artery disease (CAD) medically managed according to currently accepted guidelines, we tested whether a 1-month dietary intervention with flavanol-containing cocoa leads to an improvement of endothelial dysfunction and whether this is associated with an enhanced number and function of circulating angiogenic cells (CACs). Background Dietary flavanols can improve endothelial dysfunction. The CACs, also termed endothelial progenitor cells, are critical for vascular repair and maintenance of endothelial function. Methods In a randomized, controlled, double-masked, cross-over trial, 16 CAD patients (64 ± 3 years of age) received a dietary high-flavanol intervention (HiFI [375 mg]) and a macronutrient- and micronutrient-matched low-flavanol intervention (LoFI [9 mg]) twice daily in random order over 30 days. Results Endothelium-dependent vasomotor function, as measured by flow-mediated vasodilation of the brachial artery, improved by 47% in the HiFI period compared with the LoFI period. After HiFI, the number of CD34+/KDR+-CACs, as measured by flow cytometry, increased 2.2-fold as compared with after LoFI. The CAC functions, as measured by the capacity to survive, differentiate, proliferate, and to migrate were not different between the groups. The HiFI led to a decrease in systolic blood pressure (mean change over LoFI: −4.2 ± 2.7 mm Hg), and increase in plasma nitrite level (mean change over LoFI: 74 ± 32 nM). Applying a mixed-effects linear regression model, the results demonstrated a significant increase in flow-mediated vasodilation and a decrease in systolic blood pressure with increasing levels of CD34+/KDR+-CACs. Conclusions Sustained improvements in endothelial dysfunction by regular dietary intake of flavanols are associated with mobilization of functional CACs. (Effect of Cocoa Flavanols on Vascular Function in Optimally Treated Coronary Artery Disease Patients: Interaction Between Endothelial Progenitor Cells, Reactivity of Micro- and Macrocirculation; NCT00553774).

Christian Heiss (2018)Chronische mesenteriale Ischämie, In: Deutsche Medizinische Wochenschrift143(20)pp. 1426-1429 Georg Thieme Verlag

Was ist neu? Definition und Ursachen: Der chronischen mesenterialen Ischämie (CMI) liegen Stenosen oder Verschlüsse des Truncus coeliacus, Arteria mesenteria superior oder inferior zugrunde. Die häufigste Ursache ist die Atherosklerose (90%), aber auch eine fibromuskuläre Dysplasie oder Vasculitis. Endsprechend sind die Risikofaktoren Rauchen, arterielle Hypertonie, Dyslipidämie und hohes Lebensalter. Frauen sind häufiger betroffen als Männer. Epidemiologie: Die symptomatische CMI ist relativ selten (5% aller ischämischen intestinalen Ereignisse). Die Prävalenz der asymptomatischen CMI ist nicht gut untersucht, scheint aber bei Erwachsenen im Bereich von 14-15% zu liegen und ist häufiger bei der peripheren arteriellen Verschlusskrankheit (27%) oder abdominellem Aortenaneurysma (40%). Am häufigsten ist der Tuncus coeliacus betroffen. Diagnosestellung: Nahrungsabhängige Beschwerden zusammen mit Unterernährung aber erhaltenem Appetit und ein abdominelles Strömungsgeräusch können wichtige klinische Hinweise auf eine CMI sein, die zur Durchführung einer Duplex Ultraschalluntersuchung und funktionellen Untersuchungen in einem spezialisierten Zentrum führen sollte. Zur Planung des weiteren Vorgehens kann eine CT Angiographie notwendig sein. Therapie: Die Therapie der Wahl einer symptomatischen CMI insbesondere bei Mehrgefäßerkrankung ist die Revaskularisation. In den meisten Fällen wird aufgrund niedriger post-interventioneller Mortalität bei meist multimorbiden Patienten und ausgezeichneter klinischer und technischer Erfolgsrate dem endovaskulären Vorgehen der Vorzug gegeben. Sekundärprophylaxe: Wie bei der KHK und pAVK sollte bei Patienten mit Atherosklerose der Mesenterialarterien Lebensstilmodifikation und optimale medikamentöse Therapie mit Statinen und Aspirin zur Risikoreduktion eingesetzt werden ohne dass jedoch Studien in diesem Patientenkollektiv existieren. Nach Revaskularisation ist Plättchenhemmung indiziert. = = = What is new? Definition and causes: Chronic mesenteric ischemia (CMI) is caused by stenosis or occlusion of the celiac trunk, superior mesenteric artery or inferior artery. The most common cause is atherosclerosis (˃90%), but also fibromuscular dysplasia or vasculitis. In conclusion, the risk factors are smoking, arterial hypertension, dyslipidemia and old age. Women are more affected than men. Epidemiology: Symptomatic CMI is relatively rare (5% of all ischemic intestinal events). The prevalence of asymptomatic CMI has not been well studied but appears to be in the range of 14-15% in adults and is more common in peripheral arterial disease (27%) or abdominal aortic aneurysm (40%). The most commonly affected is the tunic coeliacus. Diagnosis: Diet-related disorders along with malnutrition but appetite and abdominal flow noise may be important clinical indications of CMI that should lead to a duplex ultrasound examination and functional examinations in a specialized center. To plan further procedures, CT angiography may be necessary. Therapy: The treatment of choice of symptomatic CMI, especially in multivessel disease, is revascularization. In most cases, because of low post-interventional mortality in mostly multimorbid patients and excellent clinical and technical success rates, endovascular procedures are preferred. Secondary prophylaxis: As with CHD and PAOD, lifestyle modification and optimal drug therapy with statins and aspirin should be used to reduce risk in patients with atherosclerosis of the mesenteric arteries, but studies in this patient population do not exist. After revascularization, platelet inhibition is indicated.

Roberto Sansone, Ana Rodriguez-Mateos, Jan Heuel, David Falk, Dominik Schuler, Rabea Wagstaff, Gunter G. C. Kuhnle, Jeremy P. E. Spencer, Hagen Schroeter, Marc W. Merx, Malte Kelm, Christian Heiss (2015)Cocoa flavanol intake improves endothelial function and Framingham Risk Score in healthy men and women: a randomised, controlled, double-masked trial: the Flaviola Health Study, In: British Journal of Nutrition114(08)pp. 1246-1255 Cambridge University Press

Cocoa flavanol (CF) intake improves endothelial function in patients with cardiovascular risk factors and disease. We investigated the effects of CF on surrogate markers of cardiovascular health in low risk, healthy, middle-aged individuals without history, signs or symptoms of CVD. In a 1-month, open-label, one-armed pilot study, bi-daily ingestion of 450 mg of CF led to a time-dependent increase in endothelial function (measured as flow-mediated vasodilation (FMD)) that plateaued after 2 weeks. Subsequently, in a randomised, controlled, double-masked, parallel-group dietary intervention trial ( NCT01799005), 100 healthy, middle-aged (35–60 years) men and women consumed either the CF-containing drink (450 mg) or a nutrient-matched CF-free control bi-daily for 1 month. The primary end point was FMD. Secondary end points included plasma lipids and blood pressure, thus enabling the calculation of Framingham Risk Scores and pulse wave velocity. At 1 month, CF increased FMD over control by 1·2 % (95 % CI 1·0, 1·4 %). CF decreased systolic and diastolic blood pressure by 4·4 mmHg (95 % CI 7·9, 0·9 mmHg) and 3·9 mmHg (95 % CI 6·7, 0·9 mmHg), pulse wave velocity by 0·4 m/s (95 % CI 0·8, 0·04 m/s), total cholesterol by 0·20 mmol/l (95 % CI 0·39, 0·01 mmol/l) and LDL-cholesterol by 0·17 mmol/l (95 % CI 0·32, 0·02 mmol/l), whereas HDL-cholesterol increased by 0·10 mmol/l (95 % CI 0·04, 0·17 mmol/l). By applying the Framingham Risk Score, CF predicted a significant lowering of 10-year risk for CHD, myocardial infarction, CVD, death from CHD and CVD. In healthy individuals, regular CF intake improved accredited cardiovascular surrogates of cardiovascular risk, demonstrating that dietary flavanols have the potential to maintain cardiovascular health even in low-risk subjects.

Geoffrey Istas, Rodrigo P. Feliciano, Timon Weber, Rocio Garcia-Villalba, Francisco Tomas-Barberan, Christian Heiss, Ana Rodriguez-Mateos (2018)Plasma urolithin metabolites correlate with improvements in endothelial function after red raspberry consumption: A double-blind randomized controlled trial, In: Archives of Biochemistry and Biophysics651pp. 43-51 Elsevier

Raspberries are a rich source of ellagitannins and anthocyanins. The aim of this work was to investigate whether raspberry consumption can improve vascular function and to understand which phenolic metabolites may be responsible for the effects. A 3 arm double-blind randomized controlled crossover human intervention trial was conducted in 10 healthy males. Flow-mediated dilation (FMD) was measured at baseline, 2 h, and 24 h post-consumption of 200 g and 400 g of red raspberries containing 201 or 403 mg of total (poly)phenols, or a matched control drink. Raspberry (poly)phenol metabolites were analyzed in plasma and urine by UPLC-QTOF mass spectrometry using authentic standards. Significant improvements in FMD were observed at 2 h (1.6% (95%CI 1.2, 1.9) and 1.2% (95% CI 0.8, 1.5)) and 24 h (1.0% (95% CI 0.6, 1.2) and 0.7% (95%CI 0.2, 0.9)) post-consumption of the 200 and 400 g raspberry drinks as compared to control, respectively. Plasma ellagic acid, urolithin A-3-glucuronide and urolithin A-sulfate correlated with the improvements in FMD at 2 and 24 h post consumption, respectively. Consumption of dietary achievable amounts of red raspberries acutely improves endothelial function up to 24 h and ellagitannins may be responsible for the observed effect.

Roberto Sansone, Maximilian Baaken, Patrick Horn, Dominik Schuler, Ralf Westenfeld, Nicolas Amabile, Malte Kelm, Christian Heiss (2018)Release of endothelial microparticles in patients with arterial hypertension, hypertensive emergencies and catheter-related injury, In: Atherosclerosis273pp. 67-74 Elsevier

Background and aims Circulating endothelial microparticles (EMPs) are increased in arterial hypertension. The role of physicomechanical factors that may induce EMP release in vivo is still unknown. We studied the relationship of EMPs and physicomechanical factors in stable arterial hypertension and hypertensive emergencies, and investigated the pattern of EMP release after mechanical endothelial injury. Methods In a pilot study, 41 subjects (50% hypertensives) were recruited. EMPs were discriminated by flow-cytometry (CD31+/41-, CD62e+, CD144+). Besides blood pressure measurements, pulse-wave-analysis was performed. Flow-mediated dilation (FMD), nitroglycerin-mediated dilation (NMD), and wall-shear-stress (WSS) were measured ultrasonographically in the brachial artery; microvascular perfusion by laser-Doppler ( NCT02795377). We studied patients with hypertensive emergencies before and 4 h after BP lowering by urapidil (n = 12) and studied the release of EMPs due to mechanical endothelial injury after coronary angiography (n = 10). Results Hypertensives exhibited increased EMPs (CD31+/41-, CD144+, CD62e+) as compared to normotensives and EMPs univariately correlated with systolic BP (SBP), augmentation index, and pulse wave velocity and inversely with FMD. CD31+/41--EMPs correlated with diameter and inversely with WSS and NMD. CD62e+ and CD144+-EMPs inversely correlated with microvascular function. During hypertensive emergency, only CD62e+ and CD144+-EMPs were further elevated and FMD was decreased compared to stable hypertensives. Blood pressure lowering decreased CD62e+ and CD144+-EMPs and increased FMD. CD31+/41—EMPs, diameter, and WSS remained unaffected. Similar to hypertensive emergency, catheter-related endothelial injury increased only CD144+ and CD62e+-EMPs. Conclusions EMP release in hypertension is complex and may involve both physicomechanical endothelial injury and activation (CD144+, CD62e+) and decreased wall shear stress (CD31+/41-). Graphical abstract In arterial hypertension, increased systolic blood pressure and decreased wall shear stress (due to greater arterial diameter) are associated with the release of endothelial microparticles (EMPs). We linked this with distinct patterns of mechanical injury, activation, and endothelial dysfunction (CD62e+ and CD144+-EMPs) and decreased endothelial protection (CD31+/41--EMPs), respectively. EMPs may be part of a vicious self-perpetuating cycle involving endothelial dysfunction.

Stephan Langer, Maria Kokozidou, Christian Heiss, Jennifer Kranz, Tina Kessler, Niklas Paulus, Thilo Krüger, Michael J. Jacobs, Christina Lente, Thomas A. Koeppel (2010)Chronic kidney disease aggravates arteriovenous fistula damage in rats, In: KIDNEY INTERNATIONAL78(12)pp. 1312-1321 Elsevier

Neointimal hyperplasia (NIH) and impaired dilatation are important contributors to arteriovenous fistula (AVF) failure. It is unclear whether chronic kidney disease (CKD) itself causes adverse remodeling in arterialized veins. Here we determined if CKD specifically triggers adverse effects on vascular remodeling and assessed whether these changes affect the function of AVFs. For this purpose, we used rats on a normal diet or on an adenine-rich diet to induce CKD and created a fistula between the right femoral artery and vein. Fistula maturation was followed noninvasively by high-resolution ultrasound (US), and groups of rats were killed on 42 and 84 days after surgery for histological and immunohistochemical analyses of the AVFs and contralateral femoral vessels. In vivo US and ex vivo morphometric analyses confirmed a significant increase in NIH in the AVFs of both groups with CKD compared to those receiving a normal diet. Furthermore, we found using histological evaluation of the fistula veins in the rats with CKD that the media shrank and their calcification increased significantly. Afferent artery dilatation was significantly impaired in CKD and the downstream fistula vein had delayed dilation after surgery. These changes were accompanied by significantly increased peak systolic velocity at the site of the anastomosis, implying stenosis. Thus, CKD triggers adverse effects on vascular remodeling in AVFs, all of which contribute to anatomical and/or functional stenosis.