sST2 Levels Show No Association with Helicobacter pylori Infection in Asymptomatic Patients: Implications for Biomarker Research.

INTRODUCTION: Helicobacter pylori (H. pylori) is a prevalent stomach bacterium that can cause a range of clinical outcomes, including gastric cancer. In recent years, soluble suppression of tumorigenicity-2 (sST2) has gained attention as a biomarker associated with various diseases, such as gastric cancer. The purpose of this study was to explore the possible connection between H. pylori infection and sST2 levels in patients who do not exhibit symptoms. METHODS: A total of 694 patients from the Salzburg Colon Cancer Prevention Initiative (Sakkopi) were included in the study. The prevalence of H. pylori infection was determined by histology, and sST2 levels were measured in serum samples. Clinical and laboratory parameters, such as age, sex, BMI, smoking status, hypertension, and metabolic syndrome, were also collected. RESULTS: The median sST2 concentration was similar between patients with (9.62; 7.18-13.44 ng/mL; p = 0.66) and without (9.67; 7.08-13.06 ng/mL) H. pylori. Logistic regression analysis did not show any association (OR 1.00; 95%CI 0.97-1.04; p = 0.93) between sST2 levels and H. pylori infection, which remained so (aOR 0.99; 95%CI 0.95-1.03; p = 0.60) after adjustment for age, sex, educational status, and metabolic syndrome. In addition, sensitivity analyses stratified by age, sex, BMI, smoking status, educational status, and the concomitant diagnosis of metabolic syndrome could not show any association between sST2 levels and H. pylori infection. CONCLUSION: The results indicate that sST2 may not serve as a valuable biomarker in the diagnosis and treatment of H. pylori infection. Our findings are of relevance for further research investigating sST2, as we could not find an influence of asymptomatic H. pylori infection on sST2 concentration. WHAT IS ALREADY KNOWN?: Soluble suppression of tumorigenicity-2 (sST2) has gained attention as a biomarker associated with various diseases, such as gastric cancer. WHAT IS NEW IN THIS STUDY?: The median sST2 concentration was similar between patients with (9.62; 7.18-13.44 ng/mL; p = 0.66) and without (9.67; 7.08-13.06 ng/mL) H. pylori. WHAT ARE THE FUTURE CLINICAL AND RESEARCH IMPLICATIONS OF THE STUDY FINDINGS?: The results indicate that sST2 may not serve as a valuable biomarker in the diagnosis and treatment of H. pylori infection.

Diverging Concentrations of Soluble Suppression of Tumorigenicity (sST2) Analyzed by two Different Assays - a Limitation for its use in Clinical Practice?

BACKGROUND: Soluble suppression of tumorigenicity (sST2) constitutes a novel biomarker with diagnostic and prognostic implications in several diseases. However, recent evidence suggests that different enzyme-linked immunosorbent assay (ELISA) kits could result in diverging serum concentrations measured. METHODS: Serum concentrations of sST2 were measured in blood of 215 patients with aortic valve stenosis using two commercially available ELISA-assays (Presage® ST2 assay and R&D). Passing and Bablok regression analysis, Bland-Altman plot, and correlation analysis were conducted. RESULTS: Values obtained by Presage® were 1.9-fold higher than concentrations measured by R&D, with a mean bias of 14,489 pg/mL between both assays. The most extreme deviations were observed in values below the median of concentrations measured by the R&D assay (21.4%, p < 0.0001). CONCLUSIONS: Our findings suggest a constant difference and a proportional bias between both investigated assays could be of special importance in circumstances where cutoffs with prognostic relevance have been calculated previously. In order to interpret sST2 concentrations correctly, the clinician should be aware of these deviations between different ELISA kits.

Endothelialization and Inflammatory Reactions After Intracardiac Device Implantation.

BACKGROUND: Due to the advances in catheter-based interventional techniques, a wide range of heart diseases can now be treated with a purely interventional approach. Little is yet known regarding biological effects at the intracardiac implantation site or the effects on endothelialization and vascular inflammation in an in vivo environment. Detailed knowledge of ongoing vascular response, the process of endothelialization, and possible systemic inflammatory reactions after implantation is crucial for the clinical routine, since implants usually remain in the body for a lifetime. METHODS: For this narrative review, we conducted an extensive profound PubMed analysis of the current literature on the endothelialization processes of intracardially implanted devices, such as persistent foramen ovale (PFO) occluders, atrial septal defect (ASD) occluders, left atrial appendage (LAA) occluders, transcatheter aortic valve implantations (TAVIs), and leadless pacemakers. Additionally, the known biological activities of common metallic and synthetic components of intracardiac devices in an "in vivo" setting have been evaluated. RESULTS: Nitinol, an alloy of nickel and titanium, is by far the most commonly used material found in intracardiac devices. Although allergies to both components are known, implantation can be performed safely in the vast majority of patients. Depending on the device used, endothelialization can be expected within a time frame of 3-6 months. For those patients with a known allergy, gold coating may be considered as a viable alternative. CONCLUSION: Based on our analysis, we conclude that the vast majority of devices are made of a material that is both safe to implant and nontoxic in long-term treatment according to the current knowledge. The literature on the respective duration of endothelialization of individual devices however is highly divergent.

Anti-coagulation for COVID-19 treatment: both anti-thrombotic and anti-inflammatory?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been linked to a higher risk of mortality compared to influenza, which is mainly due to severe secondary diseases, such as acute respiratory distress syndrome (ARDS). In turn, ARDS is characterized by an acute inflammation and an excessive activity of the coagulation cascade, rising the vulnerability for venous thromboembolic events. In order to investigate the relation of inflammation and the influence of coagulation factors on their release, human peripheral mononuclear blood cells (PBMCs) were treated with autologous serum, heparinized plasma and different doses of fibrin. Thereafter, the concentration of pro-inflammatory cytokines and chemokines in the secretome of PBMCs was measured by enzyme-linked immunosorbent assay. Our analyses revealed autologous serum to significantly increase the secretion of cytokines and chemokines after 24 h of incubation time. Furthermore, the addition of fibrin markedly increased the secretion of cytokines and chemokines by PBMCs in a dose-dependent manner. Consequently, in accordance with previous studies, our study outlines that anti-coagulation may constitute a promising tool for the treatment of SARS-CoV-2, reducing both, the cytokine storm, as well as the risk for thrombotic complications.

Tumor necrosis factor alpha-an underestimated risk predictor in patients undergoing transcatheter aortic valve replacement (TAVR)?

BACKGROUND: Systemic inflammation has been identified as a major cardiovascular risk factor in patients undergoing transcatheter aortic valve replacement (TAVR), yet currently, it is not adequately portrayed in scores for pre-interventional risk assessment. The aim of this study was to investigate the predictive ability of TNF-α in TAVR. METHODS: A total of 431 patients undergoing transfemoral TAVR were enrolled in this study. Blood samples were drawn prior to intervention, 24 h post-intervention, 4, 5, and 7 days post-intervention, and 1, 3, and 6 months post-TAVR. RESULTS: In a univariate Cox proportional hazard analysis, plasma concentrations of TNF-α after 24 h and after 5 days were associated with mortality after 12 months (after 24 h: HR 1.002 (1.000-1.004), p = 0.028; after 5d: HR 1.003 (1.001-1.005), p = 0.013). This association remained significant even after correction for confounders in a multivariate Cox regression analysis. Additionally, cut-offs were calculated. Patients above the cut-off for TNF-α after 5d had a significantly worse 12-month mortality than patients below the cut-off (18.8% vs. 2.8%, p = 0.046). CONCLUSION: Plasma levels of TNF-α after 24 h and 5 days were independently associated with 12-month mortality in patients undergoing TAVR. Thus, TNF-α could represent a novel biomarker for enhanced risk stratification in these patients.

Dynamic Changes of Heart Failure Biomarkers in Response to Parabolic Flight.

BACKGROUND: we aimed at investigating the influence of weightlessness and hypergravity by means of parabolic flight on the levels of the heart failure biomarkers H-FABP, sST2, IL-33, GDF-15, suPAR and Fetuin-A. METHODS: 14 healthy volunteers (males: eight; mean age: 28.9) undergoing 31 short-term phases of weightlessness and hypergravity were included. At different time points (baseline, 1 h/24 h after parabolic flight), venous blood was drawn and analyzed by the use of ELISA. RESULTS: sST2 evidenced a significant decrease 24 h after parabolic flight (baseline vs. 24, p = 0.009; 1 h vs. 24 h, p = 0.004). A similar finding was observed for GDF-15 (baseline vs. 24 h, p = 0.002; 1 h vs. 24 h, p = 0.025). The suPAR showed a significant decrease 24 h after parabolic flight (baseline vs. 24 h, p = 0.1726; 1 h vs. 24 h, p = 0.009). Fetuin-A showed a significant increase at 1 h and 24 h after parabolic flight (baseline vs. 24 h, p = 0.007; 1 h vs. 24 h, p = 0.04). H-FABP and IL-33 showed no significant differences at all time points. CONCLUSION: Our results suggest a reduction in cardiac stress induced by exposure to gravitational changes. Moreover, our findings indicate an influence of gravitational changes on proliferative processes and calcium homeostasis.

Analysis of Novel Cardiovascular Biomarkers in Patients With Pulmonary Hypertension (PH).

BACKGROUND: Due to the non-specific clinical presentation of patients with pulmonary hypertension (PH), diagnosis is often delayed, consequently resulting in limited therapeutic success and an impaired prognosis. In this trial, we analysed the plasma concentrations of novel cardiovascular biomarkers that reflect different pathobiological pathways (sST2: soluble suppression of tumorigenicity 2, H-FABP: heart type fatty acid binding protein, suPAR: soluble urokinase plasminogen activator receptor and GDF-15: growth-differentiation factor-15) potentially involved in PH associated vascular and right ventricular remodelling. Thus, these markers could contribute to the development of a non-invasive approach for diagnosis and therapy surveillance of PH patients in the future. METHODS: In total, we enrolled 162 patients in this single-centre retrospective analysis consisting of 88 patients suffering from PH and 74 controls. The latter were admitted for elective coronary angiography and coronary artery disease was excluded. Plasma samples of all patients were obtained and analysed for sST2, H-FABP, GDF-15 and suPAR serum concentrations by means of enzyme-linked immunosorbent assay (ELISA) kits (DuoSet ELISA, DY523B, DY957, DY807, DGAL30, R&D Systems, Minneapolis, MN, USA) after obtaining informed consent. RESULTS: Compared with controls, all of the investigated biomarkers were significantly elevated in patients with pulmonary hypertension (H-FABP median 3.5 ng/ml vs. median 0.0 ng/ml, p < 0.001; sST2 median 6364.6 pg/ml vs. median 5015.9 pg/ml, p = 0.004; GDF-15 median 1829.3 pg/ml vs. median 514.1 pg/ml, p < 0.001; suPAR median 4878.7 pg/ml vs. median 2227.0 pg/ml, p < 0.001). Interestingly, we found a significant difference in the biomarker concentrations of H-FABP, GDF-15 and suPAR between the five groups of pulmonary hypertension. In fact, we found that H-FABP levels were primarily elevated in group 2 and 3 PH, whereas the concentrations of GDF-15 and suPAR were primarily associated with pulmonary hypertension due to left sided heart disease (group 2). CONCLUSIONS: While sST2 constitutes a general biomarker of pulmonary hypertension regardless of the subtype, H-FABP, GDF-15 and suPAR represent indicators of postcapillary PH. Thereby, they could constitute potential discriminators between pre- and postcapillary PH.

Autoimmune myocarditis is not associated with left ventricular systolic dysfunction.

BACKGROUND: Experimental autoimmune myocarditis (EAM) is a common animal model for the investigation of the pathophysiology of myocarditis. Because of diverging findings from previous studies, we performed serial echocardiographic examinations throughout the course of the disease and investigated the dimensions of the murine heart and left ventricular (LV) systolic function. MATERIALS AND METHODS: Experimental autoimmune myocarditis was induced in male Balb/c mice by subcutaneous injection of a fragment of the α-myosin heavy chain (MyHC-α 614-629: Ac-SLKLMATLFSTYASAD). Transthoracic echocardiography was performed on days 0, 7 and 21 in healthy animals and mice with EAM. RESULTS: Experimental autoimmune myocarditis was associated with a reduction in LV systolic function and an increase in LV internal diameter in diastole (LVIDd) and systole (LVIDs) 7 days postimmunization. After 21 days, EAM led to a significant increase in LV-thickness (1.3-fold increase in LV anterior wall diameter in diastole [LVAWDd]), but there was no difference in LV systolic function between immunized animals and healthy controls. LV-thickness correlated well with the severity of myocarditis in the histopathological examination (LVAWDd: rs = 0.603, P = 0.003, LV anterior wall diameter in systole (LVAWDs): rs = 0.718, P < 0.0001). CONCLUSION: Our results indicate that EAM leads to an initial dilatation of the LV that is followed by ventricular "hypertrophy." On day 21, there was no significant difference in LV systolic function between immunized animals and controls. Furthermore, the ageing of the animals had a major impact on the echocardiographic parameters; therefore, the use of healthy age-matched controls seems warranted when echocardiography is performed in rodents.

Blood markers of cardiac stress after generalized convulsive seizures.

OBJECTIVE: Generalized convulsive seizures (GCS) are associated with high demands on the cardiovascular system, thereby facilitating cardiac complications. To investigate occurrence, influencing factors, and extent of cardiac stress or injury, the alterations and time course of the latest generation of cardiac blood markers were investigated after documented GCS. METHODS: Adult patients with refractory epilepsy who underwent video-electroencephalography (EEG) monitoring along with simultaneous one-lead electrocardiography (ECG) recordings were included. Cardiac biomarkers (cardiac troponin I [cTNI]; high-sensitive troponin T [hsTNT]; N-terminal prohormone of brain natriuretic peptide [NT-proBNP]; copeptin; suppression of tumorigenicity-2 [SST-2]; growth differentiation factor 15, [GDF-15]; soluble urokinase plasminogen activator receptor [suPAR]; and heart-type fatty acid binding protein [HFABP]) and catecholamines were measured at inclusion and at different time points after GCS. Periictal cardiac properties were assessed by analyzing heart rate (HR), HR variability (HRV), and corrected QT intervals(QTc). RESULTS: Thirty-six GCS (6 generalized-onset tonic-clonic seizures and 30 focal to bilateral tonic-clonic seizures) were recorded in 30 patients without a history of cardiac or renal disease. Postictal catecholamine levels were elevated more than twofold. A concomitant increase in HR and QTc, as well as a decrease in HRV, was observed. Elevations of cTNI and hsTNT were found in 3 of 30 patients (10%) and 6 of 23 patients (26%), respectively, which were associated with higher dopamine levels. Copeptin was increased considerably after most GCS, whereas SST-2, HFABP, and GDF-15 displayed only subtle variations, and suPAR was unaltered in the postictal period. Cardiac symptoms did not occur in any patient. SIGNIFICANCE: The use of more sensitive biomarkers such as hsTNT suggests that signs of cardiac stress occur in about 25% of the patients with GCS without apparent clinical symptoms. SuPAR may indicate clinically relevant troponin elevations. Copeptin could help to diagnose GCS, but specificity needs to be tested.

Disease-specific characteristics of vascular cell adhesion molecule-1 levels in patients with peripheral artery disease.

Peripheral arterial disease (PAD) is one of the most common manifestations of systemic atherosclerosis. The prevalence of unrecognized PAD is high, leading to a lack of opportunity to detect subjects at a high risk for cardiovascular events. Inflammatory processes play an important role in the disease initiation as well as in the disease progression. Vascular cell adhesion molecule 1 (VCAM-1), a biomarker of endothelial dysfunction, appears to be an important mediator in inflammatory processes. Therefore, we hypothesized that in patients with PAD, circulating VCAM-1 might be elevated due to its function in mediating adhesion of immune cells to the vascular endothelium in the process of endothelial dysfunction and inflammation, and, therefore, applicable as a diagnostic biomarker. A total of 126 non-consecutive patients were enrolled in this study, of whom 51 patients had typical clinical manifestations of PAD and as controls 75 patients with no history of PAD or cardiovascular disease. All serum samples were obtained either during hospitalization or during out-patient visits and analyzed for VCAM-1 by the ELISA. Compared with controls, median levels of VCAM-1 were significantly elevated in patients suffering from PAD (953 vs. 1352 pg/ml; p < 0.001). Furthermore, VCAM-1 appeared to be highly discriminative for the detection of PAD (AUC = 0.76; CI 0.67-0.83). We could not observe dynamics related to increasing disease stages according to Rutherford classes in patients with apparent PAD. VCAM-1 was shown to be a potential discriminator and biomarker for the severity of systemic atherosclerosis. In a logistic regression analysis, VCAM-1 was robustly associated with the diagnosis of PAD, even after correction for clinically relevant cofounders (namely age, arterial hypertension, diabetes and LDL levels). Thusly, VCAM-1 might serve as a biomarker for PAD screening and detection.

Potential mechanisms of endothelialisation in individuals implanted with a leadless pacemaker systems: An experimental in vitro study.

BACKGROUND: Leadless pacemaker technology is a promising upcoming field in clinical rhythmology. Today, the most commonly used system in the clinical setting is the Micra™ leadless pacemaker system (Medtronic). In autopsies of patients who witnessed non-pacemaker associated death, unexpected ingrowth/encapsulation within the wall of the right ventricle was reported. The occurrence of a complete encapsulation was not expected and the process of endothelialisation remains unclear. We hypothesized, that a local inflammatory response might be the cause of these findings. The aim of our experimental in-vitro study was to investigate the effect of the Micra™ system and its single components on inflammatory processes. METHODS: For this purpose, whole Micra™ pacemakers were incubated in heparin plasma from 25 healthy volunteers for 48 h at 37 °C. Furthermore, 1 g gold, steel, titanium, tungsten and nitinol wires were incubated in heparin plasma for 48 h at 37 °C as well (n = 10). To detect eventual inflammatory processes, interleukin- (IL) 1ß, IL-6, and tumor necrosis factor alpha (TNF-α), the chemokine IL-8 were measured using enzyme-linked immunosorbent assay (ELISA). Additionally, the level of transforming growth factor beta 1 (TGF-ß1) and vascular endothelial growth factor (VEGF) were analysed. RESULTS: ELISA analyses showed that the whole Micra system leads to a significant increase in the inflammatory cytokine IL-6 which correlates with the data gained by the incubation of whole blood with the different wires. In particular, 0.5 g of tungsten showed a significant rise of IL-6 which could also be found for IL-1ß and IL-8. CONCLUSIONS: The in vitro study of the Micra system showed that the material composition led to an onset of inflammatory processes in whole blood. Consequently, one may speculate that the composition of Micra pacemaker may have a local inflammatory, though subclinical, effects in patients implanted with a Micra™ pacemakers.

Pathophysiology of Calcium Mediated Ventricular Arrhythmias and Novel Therapeutic Options with Focus on Gene Therapy.

Cardiac arrhythmias constitute a major health problem with a huge impact on mortality rates and health care costs. Despite ongoing research efforts, the understanding of the molecular mechanisms and processes responsible for arrhythmogenesis remains incomplete. Given the crucial role of Ca2+-handling in action potential generation and cardiac contraction, Ca2+ channels and Ca2+ handling proteins represent promising targets for suppression of ventricular arrhythmias. Accordingly, we report the different roles of Ca2+-handling in the development of congenital as well as acquired ventricular arrhythmia syndromes. We highlight the therapeutic potential of gene therapy as a novel and innovative approach for future arrhythmia therapy. Furthermore, we discuss various promising cellular and mitochondrial targets for therapeutic gene transfer currently under investigation.

Multi-biomarker analysis in patients after transcatheter aortic valve implantation (TAVI).

BACKGROUND: In this study we sought to examine whether transcatheter aortic valve implantation (TAVI) is followed by a change in the plasma levels of novel cardiovascular biomarkers. METHODS: We collected blood samples of 79 patients with severe aortic valve stenosis undergoing TAVI before and at 7 days, 1 month, 3 months and 6 months post TAVI and analyzed the plasma concentrations of GDF-15, H-FABP, fetuin-A, galectin 3, sST2 and suPAR by means of ELISA. RESULTS: There was a significant increase in the concentration of fetuin-A (median: 52.44 mg/ml to 113.2 mg/ml, p < 0.001) and a significant decrease of H-FABP after TAVI (median: 4.835 ng/ml to 2.534 ng/ml, p < 0.001). The concentrations of suPAR and sST2 showed an initial increase (suPAR median: 2755 pg/ml 3489 pg/ml, p < 0.001; sST2 median: 5832 pg/ml to 7137 pq/ml, p < 0.001) and subsequently decreased significantly. CONCLUSION: We hypothesize that the decrease of H-FABP and the increase of fetuin-A could be due to a hemodynamic improvement after valve replacement. The initial increase of suPAR could indicate an inflammatory stimulus and the significant increase in sST2 could be due to the mechanical strain caused by implantation of the valve.

Influences of Ivabradine treatment on serum levels of cardiac biomarkers sST2, GDF-15, suPAR and H-FABP in patients with chronic heart failure.

Chronic heart failure (CHF) represents a major cause of hospitalization and death. Recent evidence shows that novel biomarkers such as soluble suppression of tumorigenicity (sST2), growth-differentiation factor-15 (GDF-15), soluble urokinase plasminogen activator receptor (suPAR) and heart-type fatty acid binding protein (H-FABP) are correlated with inflammatory and ischemic responses in CHF patients. In this study we examined the effects of Ivabradine that inhibited the hyperpolarization-activated cyclic nucleotide-gated channel (HCN channel, also called funny current If), thereby leading to selective heart rate reduction and improved myocardial oxygen supply on the cardiac biomarkers sST2, GDF-15, suPAR and H-FABP in 50 CHF patients at the University Hospital of Jena. Patients were divided into three groups based on the etiology of CHF: dilated cardiomyopathy (DCM, n=20), ischemic cardiomyopathy (ICM, n=20) and hypertensive cardiomyopathy (HCM, n=10). The patients were administered Ivabradine (5 mg, bid for 3 months, and 7.5 mg bid for further 3 months). Analyses of cardiovascular biomarkers were performed at baseline as well as at 3- and 6-month follow-ups. At 6-month follow-up, GDF-15 levels were significantly reduced compared to baseline levels (P=0.0215), indicating a reduction in the progress of cardiac remodeling. H-FABP concentration was significantly lower in DCM patients compared to ICM (1.89 vs 3.24 µg/mL) and HCM patients (1.89 vs 3.80 µg/mL), and decreased over the 6-month follow-up (P=0.0151). suPAR median levels remained elevated, implying major ongoing inflammatory processes. As shown by significant decreases in GDF-15 and H-FABP levels, a reduction in ventricular remodeling and sub-clinical ischemia could be assumed. However, markers of hemodynamic stress (sST2) and inflammation (suPAR) showed no change or progression after 6 months of Ivabradine treatment in CHF patients. Further studies are necessary to validate the clinical applicability of these novel cardiovascular biomarkers.

Specifics of fetuin-A levels in distinct types of chronic heart failure.

INTRODUCTION: Fetuin-A has been described to correlate inversely with vascular calcification both in animal models but also in patients with heart and renal disease. In this current study, we sought to investigate whether fetuin-A might be a useful marker for the discrimination of ischemic (ICM) from dilated cardiomyopathy (DCM). METHODS: A total of 124 non-consecutive patients were included in this study, 59 patients suffered from ICM and 65 patients from DCM. Serum samples were obtained during out-patient visits and analyzed for fetuin-A by ELISA. RESULTS: Median fetuin-A concentration in the overall cohort was significantly lower in ICM patients compared to DCM patients (62.2±16.4 µg/mL vs. 129.6±56.6 µg/mL; P<.001). A positive correlation of fetuin-A levels was found with BMI, cholesterol, LDL/HDL ratio and triglycerides and an inverse correlation with age (r=-.36; P<.001). Moreover, patients suffering from (stable) angina pectoris evidenced lower fetuin-A levels compared to non-symptomatic patients (73.1±22.7 µg/mL vs. 83.7±26.2 µg/mL; P=.047) CONCLUSIONS: Fetuin-A was shown to be a potential discriminator and biomarker for the differential diagnosis between ICM and DCM. Fetuin-A levels might also be helpful in the process of diagnostic decision-making in regards to invasive management or medical therapy.

Multibiomarker analysis in patients with acute myocardial infarction.

BACKGROUND: Novel biomarkers representing different pathobiological pathways and their role in patients with acute myocardial infarction (AMI) were studied. METHODS: We retrospectively analysed serum levels of soluble suppression of tumorigenicity (sST2), growth-differentiation factor-15 (GDF-15), soluble urokinase plasminogen activator receptor (suPAR), heart-type fatty acid-binding protein (H-FABP) and plasma fetuin A in blood of patients with AMI (STEMI, n = 61; NSTEMI, n = 57) compared to controls with excluded coronary artery disease (n = 76). Furthermore, detailed correlation analysis was performed. RESULTS: Compared with controls, in patients with STEMI and NSTEMI higher levels expressed as median of sST2 in pg/mL (STEMI: 13210·9, NSTEMI: 11989·1, control: 5248; P < 0·001), GDF-15 in pg/mL (STEMI: 818·8, NSTEMI 677·5, control 548·6; P < 0·001), suPAR in pg/mL (STEMI: 3461·1, NSTEMI: 3466·7, control: 2463·6; P < 0·001), H-FABP in ng/mL (STEMI: 5·8, NSTEMI: 5·4, control: 0·0; P < 0·001) and lower plasma fetuin A levels in µg/mL (STEMI: 95, NSTEMI: 54, control: 116·6; P < 0·001) were detected. Correlation analysis found clinical and biochemical parameters such as ejection fraction, length of hospital stay, creatine kinase, NT-proBNP and hs Troponin T levels as well as inflammatory markers (CRP, leucocytes) to be significantly correlated with novel biomarkers. CONCLUSION: Plasma levels of novel biomarkers were significantly elevated (sST2, GDF-15, H-FABP, suPAR) or inversely downregulated (fetuin A) in patients with AMI compared to a control group with excluded coronary artery disease. Significant correlations with various clinical parameters and standard biochemical markers were found.

Through modulation of cardiac Ca2+ handling, UCP2 affects cardiac electrophysiology and influences the susceptibility for Ca2+ -mediated arrhythmias.

NEW FINDINGS: What is the central question of this study? Knockdown of UCP2 reduces mitochondrial Ca2+ uptake. This suggests that Ucp2 knockout mice need to have additional effects on cytosolic Ca2+ handling to prevent Ca2+ overload. However, the specific mechanisms and their impact on cardiac electrophysiology remain speculative. What is the main finding and its importance? In Ucp2 knockout mice, decreased mitochondrial Ca2+ uptake is compensated for by functional inhibition of L-type Ca2+ channels and resultant shortening of action potential duration. UCP2-dependent modulations have a major impact on cardiac electrophysiology, resulting in alterations of ECG characteristics and a higher susceptibility to Ca2+ -mediated ventricular arrhythmias. Uncoupling protein 2 (mitochondrial, proton carrier) (UCP2) belongs to a superfamily of mitochondrial ion transporters. Owing to its beneficial influence on production of reactive oxygen species, it is suggested to reduce cardiac ischaemia-reperfusion injury. Recent studies have uncovered its ability to regulate mitochondrial Ca2+ uptake and therefore to influence cardiac cytosolic Ca2+ handling, indicating compensatory pathways to avoid toxic Ca2+ overload in Ucp2 knockout (Ucp2-/- ) mice. However, the specific mechanisms and their impact on cardiac electrophysiology remain speculative. Molecular analyses, whole-cell patch clamp in cardiomyocytes and ECG studies were performed in Ucp2-/- and wild-type (WT) control mice. Furthermore, to explore the impact on cardiac arrhythmogenicity, ECG monitoring was performed in basal conditions and during Ca2+ -mediated stress using Bay K 8644. Although cardiac ryanodine receptor 2, NCX1, L-type Ca2+ channel (LTCC) and SERCA2a expression were not altered, Ucp2-/- mice revealed major variations in cardiac electrophysiology. The LTCC current and APD90 were decreased in Ucp2-/- mice, indicating compensatory mechanisms. Furthermore, in Ucp2-/- mice, an increased slope factor of action potential upstrokes and more hyperpolarized resting membrane potential were measured, suggesting variations in cardiac excitability. In agreement with alterations of cellular physiology in Ucp2-/- mice, reductions in PR and QRS as well as shortening of the QTc interval were noted in ECG recordings. Importantly, an increased incidence of cellular after-depolarizations and more pronounced susceptibility to Ca2+ -mediated arrhythmias were observed. Furthermore, although expression of UCP3 was not different, levels of PRMT1 were significantly higher in Ucp2-/- mice. Our observations indicate compensatory mechanisms by which Ucp2-/- mice prevent toxic cytosolic Ca2+ overload. UCP2-dependent modulations have a major impact on cardiac electrophysiology and influence susceptibility to Ca2+ -mediated ventricular arrhythmias.

Impact of Moderate Altitude on Pro-Inflammatory Cytokines in Healthy Volunteers.

BACKGROUND: The induction of microvascular inflammation and the effects on cytokine production in blood due to hypoxia has been shown in the past. We have previously reported a statistically significant increase of the pro-inflammatory cytokine interleukin-8 (IL-8) in normobaric hypoxia in the setting of a hypoxia-chamber. In the present study, we sought to analyze plasma levels of inflammatory cytokines in a real-life stetting in order to foster our knowledge on hypoxia induced microvascular inflammation at moderate altitude. METHODS: Pro-inflammatory cytokines (IL-8, IL-6, TNF-α) were measured in an experimental field study, exposing 18 healthy volunteers to moderate hypoxia while staying at a mountain lodge in Diavolezza, Switzerland (2978 meters above sea level). Plasma cytokine levels were measured by ELISA. RESULTS: In contradiction to our results in a normobaric hypoxia-chamber, exposure to moderate hypoxia led to a significant decrease of plasma IL-8 levels in a real-life setting (from 2.902 (1.046 - 4.984) pg/mL to 1.395 (0.698 - 3.712) pg/mL, p = 0.034). Concentrations of IL-6 and TNF-α did not show statistically significant changes in comparison to baseline measurements. CONCLUSIONS: The results of this study show a decrease of proinflammatory cytokine IL-8 in a real life setting of moderate altitude in healthy individuals. Initiation of angiogenesis or subliminal stimulus for an altitude-induced inflammatory reaction may be explanations for this unexpected finding.

Long-term physical activity modulates adipsin and ANGPTL4 serum levels, a potential link to exercise-induced metabolic changes.

BACKGROUND: Within the presented prospective study, we aimed to illuminate the effect of long-term physical exercise on serum levels of adipsin (complement factor D) and angiopoietin-like 4 (ANGPTL4). Although past studies already outlined the effects of acute exercise, our trial design aimed to depict the development under long-term physical activity conditions. METHODS: Ninety-eight participants were included in the study and were asked to perform eight months of moderate physical activity for at least 150 minutes/week and/or vigorous-intensity exercise for at least 75 minutes/week. According to initial performance and performance gain throughout the study period, four groups were formed and subsequently compared. Blood sampling for the determination of routine laboratory parameters was done at baseline, after 2, 6, and 8 months. Additionally, adipsin and ANGPTL4 serum levels were concurrently quantified using commercially available ELISA kits. RESULTS: The study cohort consisted of 61.2% male participants with an average age of 49.3±6.7 years. Adipsin and ANGPTL4 were found to be strongly increased by long-term physical exercise. Participants displaying a performance gain of >2.9% throughout the study showed significantly increased serum levels of both biomarkers. CONCLUSIONS: Serum levels of adipsin and ANGPTL4 were closely tied to the individual performance gain of the participating probands. An association of adipsin levels, initial performance, and serum triglycerides was found at baseline. Interestingly, this interrelationship was not detectable after eight months of physical training. This finding might indicate adipsin's involvement in linking triglyceride-balance to individual performance and energy demands in a homeostatic state.

Soluble Suppression of Tumorigenicity 2 (sST2) in Patients with Predominantly Decompensated Right Heart Failure-A Prospective Observational Study.

Right heart failure is a major challenge in clinical practice. Soluble Suppression of Tumorigenicity-2 (sST2), a member of the interleukin-1-receptor family, may have clinical prognostic value. The aim of this study was to analyze whether sST2 correlates with signs of acute right heart decompensation. This prospective single-center study included 50 patients admitted for clinical signs of predominant right heart decompensation. Signs of reduced blood supply to other organs (e.g., renal function parameter, troponin T, NT-proBNP), diuretics, and signs of venous congestion (inferior vena cava (IVC) diameter) with fluid retention (weight gain, peripheral edema) resulting from reduced RV function were analyzed. The degree of peripheral edema was defined as none, mild (5-6 mm depressible, regression in 15-60 s) or severe (>7 mm depressible, regression in 2-3 min). sST2 levels were measured at the day of hospitalization. A total of 78.7% showed severe peripheral edema. The median concentration of sST2 was 35.2 ng/mL (25.-75. percentiles 17.2-46.7). sST2 is correlated with the peripheral edema degree (rSpearman = 0.427, p = 0.004) and the diameter of IVC (r = 0.786, p = 0.036), while NT-proBNP (r = 0.114, p = 0.456), troponin T (r = 0.123, p = 0.430), creatinine-based eGFR (r = -0.207, p = 0.195), or cystatin C-based eGFR (r = -0.032, p = 0.839) did not. sST2, but no other established marker, is correlated with peripheral and central fluid status in patients with decompensated right heart failure.