[Prognostic value of circulatory cardiac troponins in heart failure].

Circulating cardiac troponins (cTn), the proteins that regulate actin and myosin interaction during muscle contraction, are detectable in patients without typical symptoms of acute coronary syndromes. The interpretation for their elevation in this context is challenging to the physician and to the scientist. The clinical potential of measuring the release of myofibrillar cTn into the bloodstream of patients with heart failure (HF) has been suggested more than a decade ago.1 Due to the minute levels of circulating cTn compared to the limit of detection of the analytical methods available at that time, most of the following clinical investigations were confined to patients with acute decompensation or severe HF since a sizeable fraction of these patients had high (measurable) levels of plasma cTn that were positively correlated to the severity of the disease and unfavorable prognosis. In patients with milder chronic and stable HF, lower levels of cTn should be expected. Previous studies that involved small cohorts of patients with chronic HF have shown that, when detectable, cTn elevation was a negative predictive factor.2,3 In this context, the study by Pascual-Figal et al4 extends our understanding of the possible utility of circulating cTn in HF patients. They monitored 80 ambulatory patients with chronic and stable HF of nonischemic origin (NYHA class II-III, left ventricular ejection fraction <40%) for more than 2 years and periodically measured cTnT (as well as NT-proBNP) with a median interval of 3.1 months. Only a minor fraction of these patients (8.7%) were positive for cTnT (>0.01 ng/mL, the limit of detection of the assay used) at an initial visit. However, more than half of the patients had elevated cTnT levels during at least one of the subsequent determinations follow-up. This population Prognostic Value of Circulatory Cardiac Troponins in Heart Failure