Abstract 12682: Accuracy of Expert Electrocardiography versus ST-Segment Elevation Myocardial Infarction Criteria for Diagnosis of Acute Coronary Occlusion Myocardial Infarction

Abstract

Introduction: In the current STEMI paradigm of Acute Myocardial Infarction (AMI), many NonSTEMI patients have unrecognized acute coronary occlusion. Such patients do not receive emergent reperfusion and are known to have higher mortality than NSTEMI patients without occlusion. Thus, we have proposed a new Occlusion MI vs. Non-Occlusion MI (OMI vs. NOMI) paradigm. We sought to compare the diagnostic accuracy for OMI of blinded expert ECG interpretation vs. STEMI criteria advocated in the fourth Universal Definition of MI. We hypothesized that blinded expert ECG interpretation would be more accurate than STEMI criteria for the diagnosis of OMI, and that STEMI(-) OMI patients would have similar characteristics to STEMI(+) OMI but greater delays to cardiac catheterization. Methods: Retrospective case-control study of patients with suspected acute coronary syndrome, collecting demographics, laboratory results, ECGs, angiographic data, and outcomes. The primary definition of OMI was defined as either 1) acute TIMI 0-2 flow culprit or 2) TIMI 3 flow culprit with peak troponin T >1.0 ng/mL or troponin I >10.0 ng/mL. Results: 808 patients were included, of whom 49% had AMI (33% OMI; 16% NOMI). Sensitivity, specificity, and accuracy of STEMI criteria vs Expert 1 for OMI among all 808 patients were 41% vs 86%, 94% vs 91%, and 77% vs 89%, and for Expert 2 among 250 patients were 36% vs 80%, 91% vs 92%, and 76% vs 89%. When experts outperformed STEMI criteria (55% of OMI), they diagnosed OMI a median of 1.5 hours earlier than STEMI criteria. Seven key ECG findings were identified by experts as important signs of OMI in STEMI(-) cases. STEMI(-) OMI patients had similar infarct size and mortality as STEMI(+) OMI patients, but greater delays to angiography. Conclusions: Blinded expert ECG interpretation was superior to STEMI criteria for the ECG diagnosis of Occlusion MI. STEMI(-) OMI patients had greater delays to catheterization but similar outcomes to STEMI(+) OMI patients. These data support the OMI vs. NOMI paradigm and suggest that STEMI(-) OMI patients could be identified rapidly and noninvasively for emergent reperfusion using expert ECG interpretation.