Cardiac troponin I, a possible predictor of survival in patients with stable congestive heart failure.

BACKGROUND: Cardiac troponin I (cTnI) has been validated as a sensitive and specific marker of myocyte damage, and is elevated in some patients with congestive heart failure. OBJECTIVE: To assess the relationship between elevated levels of cTnI and survival in stable patients with congestive heart failure. PATIENTS AND METHODS: It was assessed whether detectable serial levels of cTnI were associated with mortality in 211 patients with stable, severe heart failure at entry and one month into the Prospective Randomized Flosequinan Longevity Evaluation (PROFILE) study. Of these patients, 66 also had measurements taken at 12 months. RESULTS: Patients were New York Heart Association (NYHA) class III (n=197) or IV (n=14), with a baseline left ventricular ejection fraction of 22+/-7% (range 8% to 35%). Patients with a detectable level of cTnI at one month had an increased mortality (OR 2.608 [95% CI 1.061 to 6.409]; P=0.037). The association between mortality and detectable cTnI levels at baseline or 12 months did not reach statistical significance. Patients with a cTnI level that rose or remained elevated between baseline and one month had a higher mortality rate (50%) than those in whom the cTnI level fell (9%) between baseline and one month (P=0.025). In a multivariate model of survival that included sex, treatment, age, left ventricular ejection fraction, NYHA class and creatinine, only detectable levels of cTnI at one month were associated with survival (P=0.037). CONCLUSIONS: cTnI is released in stable, chronic heart failure and is associated with a poor prognosis, independent of other important risk factors. The risk is particularly elevated when detectable cTnI levels rise or remain elevated over time.