Prognostic value of quantitative troponin T measurements in unstable angina/non-ST-segment elevation acute myocardial infarction treated early and predominantly with percutaneous coronary intervention

PURPOSE: To evaluate the effect of baseline cardiac troponin T measurements on in-hospital and long-term outcomes in patients with unstable angina/non-ST-segment elevation myocardial infarction who are treated with an early invasive strategy. METHODS: We conducted a prospective cohort study involving 1024 consecutive patients with unstable angina/non-ST-segment elevation myocardial infarction. Patients were stratified according to quantitative troponin T measurements on admission, and underwent coronary angiography and subsequent coronary stenting of the culprit lesion as the primary revascularization strategy within 24 hours. The primary endpoint was all-cause mortality. RESULTS: The risk of in-hospital and long-term mortality increased with absolute levels of troponin T. In-hospital mortality was 0.7% (3/449) in patients with levels < 0.010 mug/L, 2.0% (4/197) in those with levels from 0.010 to 0.035 mug/L, 3.2% (6/186) in those with levels from 0.035 to 0.229 mug/L, and 4.7% (9/192) in patients with levels > 0.229 mug/L. Cumulative 2-year mortality, rates were 2.8%, 8.0%, 10.5%, and 14.3% from the lowest to highest troponin T groups (P < 0.001). In contrast, the risk of nonfatal myocardial infarction assumed an inverted U-shaped curve and ,as lower in the lowest and highest troponin T groups. CONCLUSION: Troponin T remains a strong predictor of mortality, even at low levels in patients with unstable angina/non-ST-segment elevation myocardial infarction who are treated with early revascularization. The risk associated with elevated levels is linear for death but not for myocardial infarction. (C) 2004 by Elsevier Inc.