Impact of ESC/ACCF/AHA/WHF universal definition of myocardial infarction on mortality at 10 years

Aims: Redefinition of myocardial infarction (MI) based on specific cardiac troponins (cTn) was universally accepted in 2007. The new definition has been widely discussed for including a large spectrum of quantitative myocardial necrosis and their clinical implications remain under debate. Our aim was to assess the impact of the universal definition of MI on mortality at 10 years. Methos and results: We studied 676 consecutive patients (Pts) admitted to our intensive cardiac care unit for acute coronary syndrome (ACS) between January 1999 and December 2000. We calculated the relative risk of the total death at 10 years adjusted with the Cox proportional hazards model, between the presence and absence of MI following different definitions: (1), typical symptoms and persistent ST-segment elevation or left bundle branch block (ST-segment elevation definition); (2), typical symptoms and CK-MB activity rise and/or fall >ULN (old definition); and (3), typical symptoms and cTn I rise and/or fall >99th percentile (universal definition). The total mortality at 10 years was 23.8%. The proportion of Pts with AMI was 33.6% for ST-segment elevation definition, 55.8% for old definition, and 70.1% for universal definition. The adjusted hazard ratio of death at 10 years between the presence and absence of AMI was 0.71 (95% confidence interval (CI): 0.46-1.08; P = 0.11) for ST-segment elevation definition, 0.84 (95% CI: 0.55-1.27; P = 0.40) for old definition, and 1.58 (95% CI: 1.07-2.40; P = 0.03) for universal definition. Patients submitted to myocardial revascularization during the initial hospital stay (72%) presented a significantly lower mortality at 10 years, compared with patients not revascularized (adjusted hazard ratio: 0.63, 95% CI: 0.44-0.91; P = 0.014). Conclusions: In a population with the entire spectrum of ACSs, the universal definition of MI increased this diagnosis by one-quarter and was an independent predictor of mortality at 10 years. Furthermore, myocardial revascularization was associated with a significantly lower mortality at 10 years.