Background— Circulating cardiac troponin T, a marker of cardiomyocyte injury, predicts adverse outcome in patients with heart failure (HF) but is detectable in only a small fraction of those with chronic stable HF. We assessed the prognostic value of circulating cardiac troponin T in patients with stable chronic HF with a traditional (cTnT) and a new precommercial highly sensitive assay (hsTnT). Methods and Results— Plasma troponin T was measured in 4053 patients with chronic HF enrolled in the Valsartan Heart Failure Trial (Val-HeFT). Troponin T was detectable in 10.4% of the population with the cTnT assay (detection limit ≤0.01 ng/mL) compared with 92.0% with the new hsTnT assay (≤0.001 ng/mL). Patients with cTnT elevation or with hsTnT above the median (0.012 ng/mL) had more severe HF and worse outcome. In Cox proportional hazards models adjusting for clinical risk factors, cTnT was associated with death (780 events; hazard ratio=2.08; 95% confidence interval, 1.72 to 2.52; P <0.0001) and first hospitalization for HF (655 events; hazard ratio=1.55; 95% confidence interval, 1.25 to 1.93; P <0.0001). HsTnT was associated with the risk of death in unadjusted analysis for deciles of concentrations and in multivariable models (hazard ratio=1.05; 95% confidence interval, 1.04 to 1.07 for increments of 0.01 ng/mL; P <0.0001). Addition of hsTnT to well-calibrated models adjusted for clinical risk factors, with or without brain natriuretic peptide, significantly improved prognostic discrimination (C-index, P <0.0001 for both outcomes). Conclusions— In this large population of patients with HF, detectable cTnT predicts adverse outcomes in chronic HF. By the highly sensitive assay, troponin T retains a prognostic value at previously undetectable concentrations.

Background: The B-type or brain natriuretic peptides (BNP) and the amino-terminal probrain natriuretic peptide (NT-proBNP) are good markers of prognosis and diagnosis in chronic heart failure (HF). It is unclear, however, whether differences in their biological characteristics modify their clinical correlates and prognostic performance in HF. This work aimed to provide a direct comparison of the prognostic value of BNP and NT-proBNP in patients with chronic and stable HF. Methods: We measured BNP and NT-proBNP at baseline in 3916 patients enrolled in the Valsartan Heart Failure Trial. To identify the variables associated with both peptides, we conducted simple and multivariable linear regression analyses. We used Cox multivariable regression models to evaluate the independent prognostic value for all-cause mortality, mortality and morbidity, and hospitalization for HF. Prognostic performance was assessed by pairwise comparisons of the area under the curve of receiver-operator characteristic curves. Results: NT-proBNP and BNP had similar relationships with age, left ventrical ejection fraction, and internal diameter and creatinine clearance. Either peptide ranked as the first independent predictor of outcome after adjustment for major confounding clinical characteristics. ROC curves were almost superimposable for all-cause mortality (area under the curve (SE): BNP 0.665 (0.011) vs NT-proBNP 0.679 (0.011); P = 0.0734), but NT-proBNP was superior to BNP for predicting mortality and morbidity (P = 0.032) or hospitalization for HF (P = 0.0143). Overall sensitivity and specificity ranged from 0.590 to 0.696. Conclusions: The natriuretic peptides BNP and NT-proBNP showed subtle differences in their relation to clinical characteristics and prognostic performance in a large population of patients with chronic and stable HF. They were the most powerful independent markers of outcome in HF.

A peer-reviewed open access journal published by the National Institute of Environmental Health Sciences

Exposure to particulate matter (PM) is associated with increased incidence of cardiovascular disease and increased coagulation, but the molecular mechanisms underlying these associations remain unknown. Obesity may increase susceptibility to the adverse effects of PM exposure, exacerbating the effects on cardiovascular diseases. Extracellular vesicles (EVs), which travel in body fluids and transfer microRNAs (miRNAs) between tissues, might play an important role in PM-induced cardiovascular risk. We sought to determine whether the levels of PM with an aerodynamic diameter ≤ 10 μm (PM10) are associated with changes in fibrinogen levels, EV release, and the miRNA content of EVs (EV-miRNAs), investigating 1630 overweight/obese subjects from the SPHERE Study. Short-term exposure to PM10 (Day before blood drawing) was associated with an increased release of EVs quantified by nanoparticle tracking analysis, especially EVs derived from monocyte/macrophage components (CD14+) and platelets (CD61+) which were characterized by flow cytometry. We first profiled miRNAs of 883 subjects by the QuantStudio™ 12 K Flex Real Time PCR System and the top 40 EV-miRNAs were validated through custom miRNA plates. Nine EV-miRNAs (let-7c-5p; miR-106a-5p; miR-143-3p; miR-185-5p; miR-218-5p; miR-331-3p; miR-642-5p; miR-652-3p; miR-99b-5p) were downregulated in response to PM10 exposure and exhibited putative roles in cardiovascular disease, as highlighted by integrated network analysis. PM10 exposure was significantly associated with elevated fibrinogen levels, and five of the nine downregulated EV-miRNAs were mediators between PM10 exposure and fibrinogen levels. Research on EVs opens a new path to the investigation of the adverse health effects of air pollution exposure. EVs have the potential to act both as markers of PM susceptibility and as potential molecular mechanism in the chain of events connecting PM exposure to increased coagulation, which is frequently linked to exposure and CVD development.