T‐wave heterogeneity in standard resting 12‐lead ECGs is associated with 90‐day cardiac mortality in women following emergency department admission: A nested case–control study

BACKGROUND: We investigated whether T‐wave heterogeneity (TWH) can identify patients who are at risk for near‐term cardiac mortality. METHODS: A nested case–control analysis was performed in the 888 patients admitted to the Emergency Department (ED) of our medical center in July through September 2018 who had ≥2 serial troponin measurement tests within 6 hr for acute coronary syndrome evaluation to rule‐in or rule‐out the presence of acute myocardial infarction. Patients who died from cardiac causes during 90 days after ED admission were considered cases (n = 20; 10 women) and were matched 1:4 on sex and age with patients who survived during this period (n = 80, 40 women). TWH, that is, interlead splay of T waves, was automatically assessed from precordial leads by second central moment analysis. RESULTS: TWH(V4‐6) was significantly elevated at ED admission in 12‐lead resting ECGs of female patients who died of cardiac causes during the following 90 days compared to female survivors (100 ± 14.9 vs. 40 ± 3.6 µV, p < .0001). TWH(V4‐6) generated areas under the receiver‐operating characteristic (ROC) curve (AUC) of 0.933 in women (p < .0001) and 0.573 in men (p = .4). In women, the ROC‐guided 48‐µV TWH(V4‐6) cut point for near‐term cardiac mortality produced an adjusted odds ratio of 121.37 (95% CI: 2.89–6,699.84; p = .02) with 100% sensitivity and 82.5% specificity. In Kaplan–Meier survival analysis, TWH(V4‐6) ≥ 48 µV predicted cardiac mortality in women during 90‐day follow‐up with a hazard ratio of 27.84 (95% CI: 7.29–106.36, p < .0001). CONCLUSION: Elevated TWH(V4‐6) is associated with near‐term cardiac mortality among women evaluated for acute coronary syndrome.