Background: The major structural characteristic of congestive heart failure is myocardial cell death. The aim of our study was to determine whether the level of cardiac troponin T, a protein specific for cardiac necrosis, was increased in patients with congestive heart failure. Methods and Results: Plasma samples were obtained from 33 patients and 47 healthy control subjects. Quantitative determination of cardiac troponin T was achieved with a second-generation enzyme immunoassay without cross-reactivity with the skeletal muscle troponin T. The mean circulating level of cardiac troponin T was 0.140 ± 0.439 ng/mL in patients with heart failure and 0.0002 ± 0.001 ng/mL in the healthy controls (P = .0001). To evaluate the relation between structural degradation and functional impairment, patients in heart failure were categorized according to their radionuclide left ventricular ejection fraction (LVEF). In the 23 patients with LVEF ≤45%, cardiac troponin T was 0.163 ± 0.50 ng/mL, a level significantly higher than that in patients with LVEF >45% (P = .04). There was also a negative correlation between cardiac troponin T and LVEF (R = -0.41, P = .01). Conclusions: These data show that cardiac troponin T is increased in patients with congestive heart failure and that the level parallels the severity of the disease. We conclude that cardiac troponin T is a suitable candidate-marker molecule to monitor congestive heart failure from a structural perspective.