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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. IntroductionThe universal clinical classification (UCC) of acute myocardial infarction (AMI) recommends cardiac troponin as the preferred biomarker of cardiomyocyte necrosis.

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Introduction: The universal classification (UC) of AMI aims to facilitate cross-study analysis, yet the long-term outcomes using UC are largely unknown. Hypothesis: We tested the hypothesis that the long-term outcome of patients with AMI is better predicted by UC than ST segment classification. Methods: We conducted a prospective study of 348 consecutive patients with AMI with mean follow-up of 30.6 months. The primary outcome was the major adverse cardiovascular events (MACE) [composite of all causes of mortality, recurrent AMI, and stroke]. Multivariate and survival analysis of MACE was performed. Results: The study population was STEMI=168, NSTEMI=180, Type 1=278, Type 2=55, Type 3=5, Type 4a=2, Type 4b=5, and Type 5=3. During follow-up 80 patients died, 31 had an AMI, and 7 had a stroke. UC correlates with the ST segment classification (p<0.005). MACE free survival was different for Type 1 and Type 2 (p=0.043), but not for STEMI and NSTEMI. There was a positive association between MACE and the quartile of peak Troponin, number of cardiovascular risk factors, and number of vascular beds affected, and an inverse relationship with the utilization of discharge cardiovascular protective medications (all p≤0.01). No such inverse relationship existed for Type 2. Conclusions: UC of AMI is a better long-term predictor of MACE. The quartile of peak Troponin levels, cardiovascular risk factors, and number of vascular beds affected are independent predictors of MACE, while cardiac medications protect against MACE, except in Type 2 patients.