Quartiles of Peak Troponin Are Associated with Long-term Risk of Death in Type 1 and STEMI, but Not in Type 2 or NSTEMI Patients

Background: The prognostic value of peak cardiac troponin (cTn) in different types of acute myocardial infarction (AMI) under the universal clinical classification is unknown. Hypothesis: We tested the hypothesis that the prognostic value of cTn varies with its peak level and type of AMI. Methods: We studied 345 consecutive patients with AMI with mean follow-up Of 30.6 months according to quartiles of peak cTn level (QPTL) and the type of AMI. The study outcomes were the major adverse cardiovascular events (MACE; composite of all causes of mortality and recurrent AMI) and the individual components of MACE. Results: The study included patients with AMI Type 1 (n = 276), type 2 (n = 54), ST-segment elevation myocardial infarction (STEMI; n = 159), and non-ST-segment elevation myocardial infarction (NSTEMI; n = 186). Overall, peak cTn level was an independent predictor of MACE (hazard ratio [HR]: 1.001, 95% confidence interval [CI]: 1.000-1.003, P = 0.01) and death (HR: 1.002, 95% CI: 1.001-1.004, P = 0.003), but not of recurrent AMI. The highest risk of MACE and death was in the highest QPTL (61.6%, P = .016 and 66.3%, P = 0.021, respectively) while the highest risk of recurrent AMI was in the lowest QPTL (83.7%, P = 0.04). Quartiles of peak cTn level were significantly associated with increased risk of MACE and death in patients with Type 1 (all P = 0.01) and STEMI (P = 0.01 and P = 0.02, respectively), but no association existed in type 2 or NSTEMI patients. Conclusions: Overall, peak cTn predicts the risk of MACE and death but not the risk of AMI. While in Type 1 and STEMI patients, QPTL are associated with risk of MACE and death, no association exists in type 2 or NSTEMI patients.