Elevated cardiac troponin levels predict the risk of adverse outcome in patients with acute coronary syndromes

Background Elevations of cardiac troponin T or I ore predictive of adverse outcomes in patients with acute coronary syndromes. However, odds ratios (ORs) vary substantially between studies. This investigation refines these values by means of a meta-analysis. Methods Twenty-one studies were suitable. ORs were calculated For short-term (30 days) and long-term 15 months to 3 years) follow-up in patients with ST-segment elevation (ST up arrow), in those without ST-segment elevation (no ST up arrow), and in patients with unstable angina. The primary end point was a composite of death or nonfatal myocardial infarction. Results A total of 18,982 patients were included. At 30 days, the OR for death or myocardial infarction was 3.44 (95% confidence interval [CI], 2.94-4.03; P<.00001)for patients with positive troponin. In the ST<up arrow> group, troponin elevations carried a 2.86-fold (95% CI, 2.35-3.47; P <.0001) higher risk during short-term follow-up, which was maintained long term. The no-ST<up arrow> patients with troponin elevations manifested a 4.93-fold (95% CI, 3.77-6.45; P <.0001) increase of adverse outcomes. The OR for patients with unstable angina and positive troponin was 9.39 (95% CI, 6.46-13.67; P <.0001), For cardiac death alone, the results were similar. Conclusions Patients with acute coronary syndromes who have troponin elevations show a substantial increase in risk during short and long-term follow-up.