Cardiac troponin and outcome in acute heart failure

Cardiac troponin provides diagnostic and prognostic information in acute coronary syndromes, but its role in acute decompensated heart failure is unclear. The purpose of our study was to describe the association between elevated cardiac troponin levels and adverse events in hospitalized patients with acute decompensated heart failure.

We analyzed hospitalizations for acute decompensated heart failure between October 2001 and January 2004 that were recorded in the Acute Decompensated Heart Failure National Registry (ADHERE). Entry criteria included a troponin level that was obtained at the time of hospitalization in patients with a serum creatinine level of less than 2.0 mg per deciliter (177 micromol per liter). A positive troponin test was defined as a cardiac troponin I level of 1.0 microg per liter or higher or a cardiac troponin T level of 0.1 microg per liter or higher.

Troponin was measured at the time of admission in 84,872 of 105,388 patients (80.5%) who were hospitalized for acute decompensated heart failure. Of these patients, 67,924 had a creatinine level of less than 2.0 mg per deciliter. Cardiac troponin I was measured in 61,379 patients, and cardiac troponin T in 7880 patients (both proteins were measured in 1335 patients). Overall, 4240 patients (6.2%) were positive for troponin. Patients who were positive for troponin had lower systolic blood pressure on admission, a lower ejection fraction, and higher in-hospital mortality (8.0% vs. 2.7%, P<0.001) than those who were negative for troponin. The adjusted odds ratio for death in the group of patients with a positive troponin test was 2.55 (95% confidence interval, 2.24 to 2.89; P<0.001 by the Wald test).

In patients with acute decompensated heart failure, a positive cardiac troponin test is associated with higher in-hospital mortality, independently of other predictive variables. (ClinicalTrials.gov number, NCT00366639 [ClinicalTrials.gov].).