Clinical Predictors of QRS Duration in Patients with LBBB: Data from the AdaptResponse Trial

Abstract

Introduction Multiple clinical factors are associated with improved CRT response including QRS duration, morphology, gender, height and HF etiology. Prior studies have suggested that QRS duration is the strongest independent predictor of clinical response The AdaptResponse trial is the first large multicenter trial that is well represented with women, with gender being strongly related to QRS duration and height Hypothesis Gender and height affect intrinsic QRS duration in CRT patients with LBBB Methods The AdaptResponse trial randomized CRT indicated patients with NYHA Class II-IV HF, LBBB by Strauss criteria (QRS ≥140 ms in men, ≥130 ms in women), and baseline PR interval ≤200ms to CRT optimization with LV fusion pacing or conventional CRT Multivariable linear regression was used to assess the relation of gender, height and other baseline covariates (table) with QRS duration Results In total, 3372 subjects were randomized in 218 centers worldwide, including 1460 (43.3%) females Major baseline differences exist between male and female patients (table), including a difference of 14 cm in height (p Conclusion AdaptResponse is the largest randomized CRT trial to date, with a proportion of women (43 3%) approaching the actual proportion in the HF population AdaptResponse results will provide a better understanding of the relationship of CRT response to QRS duration and patient gender and height.