Troponins and Acute Decompensated Heart Failure
In acute decompensated heart failure, as in acute coronary syndromes, troponin elevation portends worse outcome.
Patients with clinical states other than acute coronary syndromes (ACS) often have elevated troponin levels, but the association between troponin elevation and outcomes in these patients is unknown. Using data from the 105,000 hospitalized patients in the Acute Decompensated Heart Failure National Registry (ADHERE), investigators assessed this association in 68,000 patients with acute decompensated heart failure who had troponin I or T measured within 24 hours after admission and had serum creatinine levels 2.0 mg/dL.
Overall, 6.2% of patients had a positive troponin level (defined as 1.0 μg/L for troponin I and 0.1 μg/L for troponin T). The primary outcome was all-cause in-hospital mortality; secondary outcomes included length of stay and medical management.
On admission, troponin-positive patients had significantly lower ejection fractions and lower systolic blood pressure than troponin-negative patients but were less likely to have atrial fibrillation. Within 1 day after hospitalization, the mortality rate was higher in the troponin-positive cohort. Overall, in-hospital mortality was more than twice as high in the troponin-positive cohort as in the troponin-negative cohort (adjusted odds ratio, 2.5), regardless of whether heart failure was ischemic or not. Higher troponin levels were associated with higher rates of in-hospital mortality, as in patients with ACS. In the troponin-positive group, no association was noted between type of pharmacologic treatment and outcomes. Length of stay and resource use were significantly higher in the troponin-positive group.
The increased in-hospital mortality in patients with acute decompensated heart failure who had elevated troponin levels strengthens the argument for hospital admission for such patients, even in the absence of acute coronary ischemia. Although neither telemetry nor increased staff-to-patient ratio has been proven to improve outcomes, patients with decompensated heart failure and significantly elevated troponin levels should be admitted to monitored in-hospital units until acute ischemia is excluded and heart failure is stabilized. The authors note that troponin testing is a valid risk stratification tool for patients who are admitted to the hospital with decompensated heart failure and recommend its inclusion in guidelines for the management of the disease.
— J. Stephen Bohan, MD, MS, FACP, FACEPPublished in Journal Watch Emergency Medicine May 16, 2008
Citation(s): Peacock WF IV et al. Cardiac troponin and outcome in acute heart failure. N Engl J Med 2008 May 15; 358:2117.