Monitoring of cardiac troponin I in patients with acute heart failure.

Cardiac troponin I (cTnI) and creatine kinase MB isoenzyme (CK-MB) were measured in the plasma of 37 patients with acute heart failure. Elevated plasma cTnI concentrations were found in 89% of acute heart failure patients (P < 0.001 compared with a normal population), while plasma CK-MB showed no significant difference (P = 0.09). During follow-up, serial measurements of cTnI and CK-MB were performed. In acute heart failure patients, improvement of the clinical profile was associated with declining cTnI concentrations, while deterioration of heart function was closely related to increasing cTnI. Plasma CK-MB activities remained within the normal range throughout the observation period. This preliminary study provides evidence of cardiac damage to functionally overloaded myocytes. cTnI may be a sensitive marker both for early detection of myocyte damage and for monitoring of function in patients with acute heart failure.