The new universal definition of myocardial infarction criteria improve electrocardiographic diagnosis of acute coronary syndrome

Introduction/Methods: To assess whether revised electrocardiographic (ECG) criteria improve emergency department identification of patients with acute myocardial infarction (MI) or unstable angina (UA) and predict outcome, we studied 120 patients with a nondiagnostic initial ECG by prior criteria. Electrocardiograms were read in a blinded fashion months apart with standard and then revised criteria, and analyzed by chi(2) and logistic regression analysis. Results: In 12 subjects (10%), the initial ECG was now interpreted as diagnostic of ischemia. Eleven (92%) had an MI, 1 had UA (8%), and none had a noncardiac diagnosis. Ischemic ECG changes were strongly associated with MI or UA (P=.003). At 1-year follow-up, ECG changes diagnostic of ischemia were associated with a trend toward higher mortality (25% vs 7%, P=.07), but after adjustment for clinical factors, ECG changes were not an independent predictor of 1-year mortality. Conclusions: Revision of the ECG criteria for ischemia was associated with enhanced diagnostic performance and identified a subset of patients at higher risk. (C) 2011 Elsevier Inc. All rights reserved.