T-Wave Inversion, QRS Duration, and QRS/T Angle as Electrocardiographic Predictors of the Risk for Sudden Cardiac Death

The aim of this study was to investigate the prognostic utility of isolated T-wave inversion (TWI), QRS duration, and QRS/T angle on electrocardiogram at rest as predictors for sudden cardiac death (SCD) and death from all causes. The assessment of electrocardiographic findings was based on a population-based cohort of 1,951 men (age 42 to 61 years) with a follow-up period of 20 years. Isolated TWI in the absence of ST depression, bundle branch block or major arrhythmias, prolonged QRS duration from 110 to 119 ms, and a wide QRS/T angle of >67° were identified from the 12-lead electrocardiograms. SCD was observed in 171 men (8.3%) during the follow-up. As a single electrocardiographic parameter, TWI (prevalence 2.4%) was associated with an increased risk of SCD (hazard ratio [HR] 3.30, 95% confidence interval [CI] 1.91 to 5.71, p <0.001) after adjustment for age and clinical factors. Similarly, prolonged QRS duration and wide QRS/T angle were significantly related to the risk of SCD, with HR 1.50 (95% CI 1.08 to 2.19, p = 0.017) for QRS duration and HR 3.03 (95% CI 2.23 to 4.14, p <0.001) for QRS/T angle. The integrated discrimination improvement was significant when TWI (0.014, p = 0.036) or QRS/T angle (0.015, p = 0.002) was added to the model with age and clinical factors. In conclusion, TWI, QRS duration, and QRS/T angle are significantly associated with the risk of SCD and death from all causes beyond conventional cardiovascular risk predictors in the general population.