Background: We evaluated predictors of coronary heart disease (CHD) death and sudden cardiac death (SCD) in the Atherosclerosis Risk in Communities (ARIC) study.
Methods and results: The study population included 13 621 men and women 45 to 65 years of age free from manifest cardiovascular disease at entry. Hazard ratios from Cox regression with 95% confidence intervals were computed for 18 dichotomized repolarization-related ECG variables. The average follow-up was 14 years. Independent predictors of CHD death in men were TaVR- and rate-adjusted QTend (QTea), with a 2-fold increased risk for both, and spatial angles between mean QRS and T vectors and between Tpeak (Tp) and normal R reference vectors [θ(Rm|Tm) and θ(Tp|Tref), respectively], with a >1.5-fold increased risk for both. In women, independent predictors of the risk of CHD death were θ(Rm|Tm), with a 2-fold increased risk for θ(Rm|Tm), and θ(Tp|Tref), with a 1.7-fold increased risk. Independent predictors of SCD in men were θ(Tp|Tref) and QTea, with a 2-fold increased risk, and θ(Tinit|Tterm), with a 1.6-fold increased risk. In women, θ(Tinit|Tterm) was an independent predictor of SCD, with a >3-fold increased risk, and θ(Rm|Tm) and TV1 were >2-fold for both.
Conclusions: θ(Rm|Tm) and θ(Tp|Tref), reflecting different aspects of ventricular repolarization, were independent predictors of CHD death and SCD, and TaVR and TV1 were also independent predictors. The risk levels for independent predictors for both CHD death and SCD were stronger in women than in men, and QTea was a significant predictor in men but not in women.
Keywords: electrocardiography; ischemic heart disease; prognosis; repolarization; sudden death.