Hyperacute T Waves Are Specific for Occlusion Myocardial Infarction, Even Without Diagnostic ST-Segment Elevation
H. Pendell Meyers, František Šimančík, Robert Herman, Adam Rafajdus, William Frick, José Nunes de Alencar, Emre Aslanger, Stephen W. Smith
Abstract
BACKGROUND: Despite no objective definition, hyperacute T waves (HATWs) are recommended by the American College of Cardiology as a ST-segment elevation myocardial infarction (STEMI) equivalent finding, requiring emergent reperfusion. OBJECTIVES: We sought to derive and validate a quantitative definition of HATW. METHODS: We retrospectively evaluated adults with possible acute coronary syndrome across five percutaneous coronary intervention centers. Exclusions were lack of preangiogram ECG, QRS duration ≥110 ms, and elevated troponin without angiogram. The outcome definition was myocardial infarction with TIMI flow grade 0-1 culprit lesion. ECG measures included T-wave magnitude (T-wave area relative to QRS amplitude) and symmetry (T-wave peak-to-end time relative to onset-to-peak time). The HATW score was derived and evaluated on separate groups. The primary analysis was HATW score performance for acute coronary occlusion in patients without STEMI criteria. RESULTS: 3,274 patients were reviewed, and 618 were excluded. 1,261 and 1,395 patients were allocated to derivation and validation groups. In derivation, the optimal HATW score threshold for ≥98% specificity was 2 consecutive leads with mean HATW score ≥0.7. In validation, the performance for acute coronary occlusion in the subset without STEMI criteria (N = 1,300) was 98.4% specificity, 20.7% sensitivity, 47.4% positive predictive value, and 12.54 positive likelihood ratio. Among patients without STEMI criteria but positive HATW score, 84% had a culprit lesion causing acute myocardial infarction. CONCLUSIONS: The HATW score is the first objective definition of HATW showing significant clinical utility as an ECG finding of acute coronary occlusion in potential acute coronary syndrome patients.