Introduction: We evaluated repolarization-related predictors of coronary heart disease (CHD) death and sudden cardiac death (SCD) in men and women with cardiovascular disease (CVD) in the Atherosclerosis Risk in Communities (ARIC) study.
Methods and results: Hazard ratios (HR) from Cox regression were computed for 11 ECG measures of repolarization in 1384 subjects (50% women) 45 to 65years of age. The average follow-up was 14years. Based on electrophysiological considerations the spatial angle between Tpeak and normal repolarization reference vector [Ѳ(Tp|Tref)], STJV6 amplitude, QRS duration and Tonset and Tpeak vector magnitude ratio (ToV/TpV) were considered as primary candidates for independent mortality predictors, and as an alternative set TaVR and TV1 amplitudes and the spatial angle between the initial and terminal T vectors [Ѳ(Tinit|Tterm)]. From the primary set [Ѳ(Tp|Tref)] was a strong independent predictor for CHD death (nearly 4-fold increased risk in men and 2-fold increased risk in women) and for SCD [Ѳ(Tinit|Tterm)] in men (3.4-fold increased risk) and (ToV/TpV) in women (7.76-fold increased risk). From the alternative set of independent predictors TaVR amplitude negativity reduced to less than 150μV (1.5mm) was a strong mortality predictor with an approximately 3-fold increased risk for CHD death and SCD in men and women.
Conclusions: The strongest independent predictors of CHD death were [Ѳ(Tp|Tref)] in men and TaVR in women and of SCD were [Ѳ(Tp|Tref)] in men and ToV/TpV in women. Overall, TaVR amplitude negativity reduced to less than 150μV (1.5mm) was the most consistent mortality predictor in all subgroups. These ECG variables may warrant consideration for identification of high risk men and women for more intense preventive intervention.
Keywords: Coronary heart disease; ECG; QT; Repolarization; Risk factors; Sudden cardiac death.
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