Prognostic significance of admission cardiac troponin T in patients treated successfully with direct pertutaneous interventions for acute ST-segment elevation myocardial infarction

Background: Cardiac troponin T (cTnT) elevations at admission indicate a high-risk subgroup of patients with acute ST-segment elevation myocardial infarction, possibly due to a higher failure rate of reperfusion therapies. Objective: We sought to determine the predictive role of admission cTnT in patients with ST-segment elevation myocardial infarction undergoing successful direct percutaneous coronary intervention. Methods: A total of 218 consecutive patients with ST-segment elevation myocardial infarction were enrolled. Patients were stratified according to admission cTnT and infarct location. They were followed prospectively for short-term and long-term outcomes. Results: A positive cTnT (47.7%) was associated with higher mortality rates at 30 days (14.4% vs. 3.5%, p = .003) and 12 months (17.3% vs. 4.4%, p = .007). cTnT allowed discrimination of patients at high and low risk for cardiac death at 30 days and 12 months among anterior (19.2% vs. 7.9%, p = .19, and 25% vs. 13.2%, p = .22, respectively) and, more impressively, among nonanterior acute myocardial infarction (9.6% vs. 1.3%, p = .04, and 11.5% vs. 1.3%, P = .017, respectively). In multivariate analysis, older age, anterior infarct location, and depressed left ventricular function were the most potent independent predictors of future risk. Among clinical variables available at admission, cTnT indicated independently a higher risk of cardiac death (odds ratio, 3.1 [1.07-9.01], p = .038). This increased risk associated with a positive cTnT was almost independent of time delays from onset of symptoms to admission (3.8 vs. 2.3 hrs in cTnT-positive vs. cTnT-negative patients, p < .001). Conclusions: Admission cTnT is a strong predictor of future cardiac risk in patients with ST-segment elevation myocardial infarction, despite successful restoration of Thrombolysis in Myocardial Infarction grade 3 coronary flow by direct percutaneous coronary intervention.