Hyperacute T Waves Are Specific for Occlusion Myocardial Infarction, Even Without Diagnostic ST-Segment Elevation

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.

We sought to derive and validate a quantitative definition of HATW.

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.

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.

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.