Abstract 2852: New ESC/ACC Definition of Myocardial Infarction and Long-Term Mortality in Patients Undergoing Early Invasive Treatment
Background: Data about the prognostic impact of new European Society of Cardiology/American College of Cardiology (ESC/ACC) guidelines for definition of myocardial infarction (MI) on clinical outcome are inconsistent. Our study evaluated the long-term mortality in patients with acute non-ST segment elevation myocardial infarction (NSTEMI) according to current ESC/ACC guidelines that are not meeting World Health Organization (WHO) criteria for MI.
Methods: This historical cohort study included 1,024 consecutive patients with acute coronary syndrome classified into unstable angina (UA), “classic NSTEMI” according to WHO definition and “new NSTEMI” according to new ESC/ACC definition but not meeting WHO criteria for MI. All patients underwent coronary angiography and, if appropriate, subsequent stenting of the culprit lesion as the primary revascularization strategy within 24 hours of admission. The primary endpoint was all-cause mortality during long-term follow-up of up to 48 months.
Results: During follow-up (median 16 months, interquartile range 6 to 29 month) 67 deaths and 42 non-fatal myocardial infarctions occurred. Kaplan-Meier survival analysis showed cumulative four-year mortality rates of 8.5% in patients with UA, 9.1% in patients with “classic NSTEMI”, and 26.7% in patients with “new NSTEMI” not meeting WHO criteria for MI (p<0.001). Cox regression analysis confirmed “new NSTEMI” as predictor of mortality (hazard ratio, 3.067 [95% CI, 1.894 to 4.975]; p<0.001) whereas “classic NSTEMI” failed to demonstrate a predictive value (p=0.814).
Conclusion: Current ESC/ACC definitions of MI have a major impact on long-term mortality in patients with NSTEMI that are not meeting WHO criteria for MI.