Deoxyribonuclease 1 Q222R single nucleotide polymorphism and long-term mortality after acute myocardial infarction.

Upon activation, neutrophils release neutrophil extracellular traps (NETs), which contribute to circulating DNA burden and thrombosis, including ST-segment elevation myocardial infarction (STEMI). Deoxyribonuclease (DNase) 1 degrades circulating DNA and NETs. Lower DNase activity correlates with NET burden and infarct size. The DNase 1 Q222R single nucleotide polymorphism (SNP), impairing DNase 1 function, is linked with myocardial infarction. We assessed whether the Q222R SNP is connected to increased NET burden in STEMI and influences long-term outcomes. We enrolled 711 STEMI patients undergoing primary percutaneous coronary intervention (pPCI), and 1422 controls. Genotyping was performed for DNase 1 Q222R SNP. DNase activity, double-stranded (ds)DNA and citrullinated histone H3 were determined in culprit site and peripheral plasma during pPCI. The association of the Q222R variant on cardiovascular and all-cause mortality was assessed by multivariable Cox regression adjusted for cardiovascular risk factors. Homozygous Q222R DNase 1 variant was present in 64 (9.0%) STEMI patients, at the same frequency as in controls. Patients homozygous for Q222R displayed less DNase activity and increased circulating DNA burden. In overall patients, median survival was 60 months. Homozygous Q222R variant was independently associated with cardiovascular and all-cause mortality after STEMI. dsDNA/DNase ratio independently predicted cardiovascular and all-cause mortality. These findings highlight that the Q222R DNase 1 SNP is associated with increased NET burden and decreased compensatory DNase activity, and may serve as an independent risk factor for poor outcome after STEMI.

Interruption of vascular endothelial growth factor receptor 2 signaling induces a proliferative pulmonary vasculopathy and pulmonary hypertension.

Pulmonary arterial hypertension is a severe and progressive disease characterized by a pulmonary vascular remodeling process with expansion of collateral endothelial cells and total vessel occlusion. Endothelial cells are believed to be at the forefront of the disease process. Vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2 (VEGFR-2), play a central role in angiogenesis, endothelial cell protection, but also in the destabilization of endothelial barrier function. Therefore, we investigated the consequences of altered VEGF signaling in an experimental model, and looked for translational correlates of this observation in patients. We performed an endothelial cell-specific conditional deletion of the kinase insert domain protein receptor (kdr) gene, coding for VEGFR-2, in C57/BL6 mice (Kdr∆end) and held them in an environmental chamber with 10% FiO2 or under normoxia for 6 weeks. Kdr knockout led to a mild PH phenotype under normoxia that worsened under hypoxia. Kdr∆end mice exhibited a significant increase in pulmonary arterial wall thickness, muscularization, and VEGFR-3+ endothelial cells obliterating the pulmonary artery vessel lumen. We observed the same proliferative vasculopathy in our rodent model as seen in patients receiving anti-angiogenic therapy. Serum VEGF-a levels were elevated both in the experimental model and in humans receiving bevacizumab. Interrupted VEGF signaling leads to a pulmonary proliferative arteriopathy in rodents after direct ablative gene manipulation of Kdr. Histologically, similar vascular lesions can be observed in patients receiving anti-VEGF treatment. Our findings illustrate the importance of VEGF signaling for maintenance of pulmonary vascular patency.

Neutrophil extracellular traps and fibrocytes in ST-segment elevation myocardial infarction.

Leukocyte-mediated inflammation is central in atherothrombosis and ST-segment elevation myocardial infarction (STEMI). Neutrophil extracellular traps (NETs) have been shown to enhance atherothrombosis and stimulate fibroblast function. We analyzed the effects of NETs on cardiac remodeling after STEMI. We measured double-stranded (ds)DNA and citrullinated histone H3 (citH3) as NET surrogate markers in human culprit site and femoral blood collected during primary percutaneous coronary intervention (n = 50). Fibrocytes were characterized in whole blood by flow cytometry, and in culprit site thrombi and myocardium by immunofluorescence. To investigate mechanisms of fibrocyte activation, isolated NETs were used to induce fibrocyte responses in vitro. Enzymatic infarct size was assessed using creatine-phosphokinase isoform MB area under the curve. Left ventricular function was measured by transthoracic echocardiography. NET surrogate markers were increased at the culprit site compared to the femoral site and were positively correlated with infarct size and left ventricular dysfunction at follow-up. In vitro, NETs promoted fibrocyte differentiation from monocytes and induced fibrocyte activation. Highly activated fibrocytes accumulated at the culprit site and in the infarct transition zone. Our data suggest that NETs might be important mediators of fibrotic remodeling after STEMI, possibly by stimulating fibrocytes.

Metabolomics implicate eicosanoids in severe functional mitral regurgitation.

AIMS: Secondary, or functional, mitral regurgitation (FMR) was recently recognized as a separate clinical entity, complicating heart failure with reduced ejection fraction (HFrEF) and entailing particularly poor outcome. Currently, there is a lack of targeted therapies for FMR due to the fact that pathomechanisms leading to FMR progression are incompletely understood. In this study, we sought to perform metabolomic profiling of HFrEF patients with severe FMR, comparing results to patients with no or mild FMR. METHODS AND RESULTS: Targeted plasma metabolomics and untargeted eicosanoid analyses were performed in samples drawn from HFrEF patients (n = 80) on optimal guideline-directed medical therapy. Specifically, 17 eicosanoids and 188 metabolites were analysed. Forty-seven patients (58.8%) had severe FMR, and 33 patients (41.2%) had no or non-severe FMR. Comparison of eicosanoid levels between groups, accounting for age, body mass index, and sex, revealed significant up-regulation of six eicosanoids (11,12-EET, 13(R)-HODE, 12(S)-HETE, 8,9-DiHETrE, metPGJ2, and 20-HDoHE) in severe FMR patients. Metabolites did not differ significantly. In patients with severe FMR, but not in those without severe FMR, levels of 8,9-DiHETrE above a cut-off specified by receiver-operating characteristic analysis independently predicted all-cause mortality after a median follow-up of 43 [interquartile range 38, 48] months [hazard ratio 12.488 (95% confidence interval 3.835-40.666), P < 0.0001]. CONCLUSIONS: We report the up-regulation of various eicosanoids in patients with severe FMR, with 8,9-DiHETrE appearing to predict mortality. Our observations may serve as a nucleus for further investigations into the causes and consequences of metabolic derangements in this important valvular abnormality.

Cerebral Protection in TAVR-Can We Do Without? A Real-World All-Comer Intention-to-Treat Study-Impact on Stroke Rate, Length of Hospital Stay, and Twelve-Month Mortality.

Background: Stroke associated with transcatheter aortic valve replacement (TAVR) is a potentially devastating complication. Until recently, the Sentinel™ Cerebral Protection System (CPS; Boston Scientific, Marlborough, MA, USA) has been the only commercially available device for mechanical prevention of TAVR-related stroke. However, its effectiveness is still undetermined. Objectives: To explore the impact of Sentinel™ on stroke rate, length of hospital stay (LOS), and twelve-month mortality in a single-center, real-world, all-comers TAVR cohort. Material and Methods: Between January 2019 and August 2020 consecutive patients were assigned to TAVR with or without Sentinel™ in a 1:1 fashion according to the treating operator. We defined as primary endpoint clinically detectable cerebrovascular events within 72 h after TAVR and as secondary endpoints LOS and 12-month mortality. Logistic and linear regression analyses were used to assess associations of Sentinel™ use with endpoints. Results: Of 411 patients (80 ± 7 y/o, 47.4% female, EuroSCORE II 6.3 ± 5.9%), Sentinel™ was used in 213 (51.8%), with both filters correctly deployed in 189 (46.0%). Twenty (4.9%) cerebrovascular events were recorded, ten (2.4%) of which were disabling strokes. Patients with Sentinel™ suffered 71% less (univariate analysis; OR 0.29, 95%CI 0.11-0.82; p = 0.02) and, respectively, 76% less (multivariate analysis; OR 0.24, 95%CI 0.08-0.76; p = 0.02) cerebrovascular events compared to patients without Sentinel™. Sentinel™ use was also significantly associated with shorter LOS (Regression coefficient -2.47, 95%CI -4.08, -0.87; p < 0.01) and lower 12-month all-cause mortality (OR 0.45; 95%CI 0.22-0.93; p = 0.03). Conclusion: In the present prospective all-comers TAVR cohort, patients with Sentinel™ use showed (1) lower rates of cerebrovascular events, (2) shortened LOS, and (3) improved 12-month survival. These data promote the use of a CPS when implanting TAVR valves.

Neutrophil Extracellular Traps Induce MCP-1 at the Culprit Site in ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Leukocyte-mediated inflammation is crucial in ST-segment elevation myocardial infarction (STEMI). We recently observed that neutrophil extracellular traps (NETs) are increased at the culprit site, promoting activation and differentiation of fibrocytes, cells with mesenchymal and leukocytic properties. Fibrocyte migration is mediated by monocyte chemoattractant protein (MCP)-1 and C-C chemokine receptor type 2 (CCR2). We investigated the interplay between NETs, fibrocyte function, and MCP-1 in STEMI. METHODS: Culprit site and peripheral blood samples of STEMI patients were drawn during primary percutaneous coronary intervention. MCP-1 and the NET marker citrullinated histone H3 (citH3) were measured by ELISA while double-stranded DNA was stained with a fluorescent dye. The influence of MCP-1 on NET formation in vitro was assessed using isolated healthy donor neutrophils. Human coronary artery endothelial cells (hCAECs) were stimulated with isolated NETs, and MCP-1 gene expression was measured by ELISA and qPCR. CCR2 expression of culprit site and peripheral blood fibrocytes was characterized by flow cytometry. Healthy donor fibrocyte receptor expression and chemotaxis were investigated in response to stimulation with MCP-1 and NETs in vitro. RESULTS: NETs and concentrations of MCP-1 were increased at the culprit site of 50 consecutive STEMI patients. NET stimulation of hCAECs induced transcription of ICAM-1, IL-6, and MCP-1, and secretion of MCP-1. MCP-1 promoted NET formation of healthy donor neutrophils in vitro. An increasing MCP-1 gradient correlated with fibrocyte accumulation at the culprit site. Locally increased MCP-1 levels were negatively correlated with CCR2 expression on fibrocytes. MCP-1 and NETs induced CCR2 downregulation on fibrocytes in vitro. NETs did not function as a chemotactic stimulus for fibrocytes or monocytes and could block migration in response to MCP-1 for both cell populations. CONCLUSION: NETs function as signaling scaffolds at the culprit site of STEMI. NETs assist MCP-1 and ICAM-1 release from culprit site coronary artery endothelial cells. MCP-1 facilitates further NETosis. Monocytes enter the culprit site along an MCP-1 gradient, to transdifferentiate into fibrocytes in the presence of NETs.

Chronic thromboembolic pulmonary hypertension in Austria and Japan.

OBJECTIVE: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by one or more of the following features: intraluminal thrombus organization, fibrous stenosis, and complete obliteration of major pulmonary arteries, amenable to significant improvement by pulmonary endarterectomy (PEA) or balloon pulmonary angioplasty, and medical treatments with vasodilators. Because treatment practices and outcomes differ in Europe versus Japan, we hypothesized that population-based characteristics of pulmonary vascular phenotypes may exist in Austria compared with Japan. The objectives of this study were to analyze clinical characteristics, hemodynamics, and PEA specimens in consecutive patients with CTEPH undergoing PEA in Austria and Japan. METHODS: Clinical features, hemodynamics, and PEA specimens were collected and analyzed in patients with CTEPH undergoing PEA, and clinical features and hemodynamics were collected and analyzed in patients with not-operated CTEPH and in patients with nonthromboembolic pulmonary arterial hypertension. RESULTS: Apart from key differences between Austrian and Japanese patients regarding body size, lung function vital capacity, cardiac output, and serum high-density lipoprotein levels, Austrian patients were more likely to be obese, have greater hematocrits and greater white blood cells counts, greater C-reactive protein levels, and significantly elevated serum myeloperoxidase levels compared with Japanese patients with CTEPH. Analysis of PEA specimens demonstrated more proximal thrombus and more fresh red thrombus components in Austrian patients. CONCLUSIONS: This study documents an inflammatory thrombotic phenotype in Austrian compared with Japanese patients with CTEPH that may be a determinant of differential treatment outcomes.

Quality of medical therapy in heart failure patients undergoing elective revascularisation: A protective effect of disease modifying therapy at discharge.

The STICH(-ES) trial showed that coronary artery bypass grafting was superior to medical therapy alone in treating ischemic heart failure. However, dosages of disease modifying drugs were not reported. We included 128 (84% male, mean age 66 ± 11 years) consecutive patients with ischemic heart failure and an ejection fraction ≤35% undergoing isolated elective coronary artery bypass grafting. We defined optimal medical therapy (OMT) as prescription of ≥50% dosages of guideline recommended medications (i.e. beta-blocker (BB) and renin angiotensin system (RAS) antagonist) plus prescription of a mineralocorticoid receptor antagonist (MRA). The mean logistic EuroSCORE was 12.3 ± 13.8%. The five year survival was 74%. At discharge, 111 patients (87%) were on a BB and 106 (83%) were on a RAS antagonist. Forty-nine patients (38%) received an MRA. Only 8 patients (6%) received OMT. A Cox regression analysis revealed EuroSCORE (p < 0.001) and the use of MRA (p = 0.003) and BB (p = 0.037) at discharge as significant predictors of 5 year survival. Prescription rates of heart failure medication are comparable to those reported in the STICH trial, but rates of OMT are very low at admission and discharge. Prescription of BB and MRA was associated with improved survival, highlighting the need for disease management programs and rigorous discharge management.

Pro-oxidant HDL predicts poor outcome in patients with ST-elevation acute coronary syndrome.

Oxidative stress affects clinical outcome in patients with ST-elevation acute coronary syndrome (STE-ACS). Although high-density lipoprotein (HDL) particles are generally considered protective, deleterious properties of HDL have been observed in patients with acute myocardial infarction. Here, we analysed the association between pro-oxidant HDL and all-cause mortality in STE-ACS patients. We determined the antioxidant function of HDL in 247 prospectively enrolled patients undergoing primary percutaneous coronary intervention for STE-ACS. Patients were stratified as by a pro-oxidant serum HDL oxidant index (HOI≥ 1) or with an antioxidant serum HOI (HOL< 1) capacity. Multivariate regression analysis was used to relate HOI to survival. The median follow-up time was 23 months (IQR 14.4-40.0 months). Pro-oxidant HDL was observed in 44.1 % of STE-ACS patients and was independently associated with all-cause mortality with a hazard ratio of 3.30(95 %CI 1.50-7.27, p = 0.003). Mortality rates were higher in patients with baseline pro-oxidant HDL compared to patients with preserved HDL function at 30 days (11.9 % vs 2.2 %, p=0.002), and at 4 years (22.9 % vs 8.7 %, p=0.002). Elevated neutrophil counts were a strong and independent predictor for pro-oxidant HDL with an odds ratio per standard deviation of 1.50 (95 %CI 1.11-2.03, p=0.008), as was history of prior acute myocardial infarction, elevated triglycerides levels and reduced glomerular filtration rate. In conclusion, pro-oxidant HDL represents a strong and independent predictor of long-term as well as short-term all-cause mortality in STE-ACS patients. Elevated neutrophil counts predicted the presence of serum pro-oxidant HDL. The maintenance of HDL functions might be a promising therapeutic target in STE-ACS patients.