Predictors of functional mitral regurgitation improvement in patients with left bundle branch block treated with left bundle branch area pacing.

Background: Functional mitral regurgitation (FMR) and its severity are associated with adverse outcomes in heart failure patients. This study aims to analyze the predictors of FMR improvement after successful left bundle branch area pacing (LBBAP) in patients with LVEF < 50% and complete left bundle branch block (CLBBB).

Methods: Consecutive patients with LVEF < 50% and CLBBB who underwent successful LBBAP from July 2018 to July 2023 were retrospectively identified.