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 post-acute.