Frontal T-wave axis deviation and risk of sudden cardiac death in coronary syndromes

Abstract

Background Frontal T-wave axis (TA) and QRS–T angle (QRSTA) are automated ECG measures that reflect depolarisation–repolarisation abnormalities—and have been linked to mortality. We tested whether increasing deviation in TA/QRSTA predicts adjudicated sudden cardiac death (SCD) events in patients undergoing coronary angiography—elective (chronic coronary syndrome) and acute (acute coronary syndrome)—and whether signals differ when ECGs are recorded postacute. Methods Retrospective consecutive cohort at Tampere University Hospital, 2007–2018. Exposures were automatically measured frontal TA and QRSTA (Marquette 12SL). Primary endpoint was SCD event (true SCD, resuscitated SCA or implantable cardioverter defibrillator-terminated VF/very fast ventricular tachycardia) adjudicated to guideline definitions, with Fine–Gray competing-risk models adjusted for clinical covariates. Follow-up through 31 December 2022. Results We analysed 18 828 patients (elective n=10 303; acute n=8525; median follow-up 9.0 and 7.8 years). In the elective cohort, SCD hazard increased monotonically with TA/QRSTA deviation; severely abnormal TA (<−75° or >165°) HR 4.06 (95% CI 2.94 to 5.61) and severely abnormal QRSTA (≥151°) HR 3.16 (2.35–4.24). Associations persisted after excluding left ventricular ejection fraction (LVEF) ≤35%. In the acute cohort, effects were smaller and non-monotonic (severely abnormal TA HR 2.01 (1.42–2.86); QRSTA HR 1.73 (1.24–2.39)). In a sensitivity cohort with ECGs 30–365 days postangiography (acute 30, n=5529), the TA–SCD association resembled the elective setting (severely abnormal TA HR 2.69 (1.70–4.24)); QRSTA was not significant. Conclusion Severity of frontal TA deviation is a robust, graded marker of SCD risk in angiography patients, strongest in elective and postacute settings; QRSTA is supportive but weaker. These automated, low-cost metrics could augment SCD risk stratification beyond LVEF, warranting external validation and clinical utility testing.