Background: Information is limited about ECG predictors of the risk of incident congestive heart failure (CHF), particularly in women without overt manifestations of cardiovascular disease (CVD).
Methods and results: We evaluated hazard ratios for incident CHF and all-cause mortality using Cox regression in 38,283 participants of the Women's Health Initiative (WHI) during a 9-year follow-up. All risk models were adjusted for demographic and available clinical and therapeutic variables (multivariable-adjusted models). A backward selection procedure was used to identify dominant predictors among those that were significant as individual ECG predictors. Eleven ECG variables were significant predictors of incident CHF, with none of them having a significant interaction with baseline CVD status. From 6 dominant ECG predictors, wide QRS/T angle had a nearly 3-fold increased risk in multivariable-adjusted single ECG variable models. Two other repolarization variables, STV5 depression and high TV1 amplitude, and 2 QRS-related variables, QRS non-dipolar voltage and myocardial infarction (MI) by ECG, were all associated with &2-fold increase of incident CHF risk. Overall, 11 of the 12 ECG variables were significant predictors of all-cause mortality. Four variables had a significant interaction with CVD status requiring stratification. Three among these 4 were strong, dominant predictors in the CVD group: ECG MI, wide QRS/T angle, and low TV5 amplitude had risk increase from >2-fold to 3-fold, with considerably lower risks in the CVD-free group.
Conclusions: Several repolarization variables in postmenopausal women are predictors of the risk of incident CHF and all-cause mortality as important as old ECG MI.