Measurement of serum levels of cytosolic and myofibril components of cardiac tissue could indicate ongoing myocardial damage in patients with chronic heart failure.

We correlated serum levels of a cytosolic marker (heart-type fatty acid–binding protein) and a myofibril marker (troponin T) with the severity of symptoms (based on the New York Heart Association [NYHA] class), neurohumoral derangement, and subsequent cardiac events in 56 patients with chronic heart failure.

Mean (± SD) levels of heart-type fatty acid–binding protein were greater in patients with NYHA class III or IV heart failure (9.9 ± 5.2 ng/mL) than in those with NYHA class II (4.9 ± 1.9 ng/mL, P <0.0001). Detection of troponin T (≥0.02 ng/mL) was also more common in patients with worse heart failure (81% [13/16] in class III or IV vs. 43% [17/40] in class II, P = 0.02). Significant correlations were found between heart-type fatty acid–binding protein levels and plasma levels of A-type natriuretic peptide (r = 0.45, P = 0.0004), B-type natriuretic peptide (r = 0.66, P <0.0001), and norepinephrine (r = 0.36, P = 0.006). Male sex (hazard ratio [HR] = 5.0; 95% confidence interval [CI]: 1.3 to 19), detectable troponin T levels (HR = 7.0; 95% CI: 1.1 to 44), heart-type fatty acid–binding protein (HR = 2.6 per 3.9-ng/mL increase; 95% CI: 1.1 to 6.5), and left ventricular ejection fraction (HR = 3.6 per 15% decrease; 95% CI: 1.2 to 11) were independently associated with subsequent cardiac events (8 deaths or 10 readmissions because of worsening heart failure).

Heart-type fatty acid–binding protein and troponin T are markers of ongoing myocardial damage, and are associated with subsequent cardiac events in patients with chronic heart failure.