Incidence and Predictors of Pacing-Induced Cardiomyopathy in Paced Patients Undergoing Attempted Left Bundle Branch Area Pacing

Abstract

Background: The incidence and predictors of pacing-induced cardiomyopathy (PICM) in patients undergoing attempted left bundle branch area pacing (LBBAP) are unknown. Objective: To examine the incidence and predictors of PICM in patients with preserved left ventricular ejection fraction (LVEF) and atrioventricular block (AVB) undergoing attempted LBBAP. Methods: The study cohort included consecutive patients undergoing an attempt at LBBAP at the Cleveland Clinic from 2018 until 2022 with preserved LVEF and AVB. PICM was defined as post-PM LVEF decrease to < 50% and > 5%, > 10% decrease from pre-PM implantation. Patients who had alternative reasons for a decrease in LVEF during follow-up were excluded. LBBAP was defined as meeting common criteria for LBBAP and the incidence of PICM was evaluated. Results: A total of 173 patients were included. PICM developed in 13/173 (7.5%) of patients at 26 (IQR 7–70) weeks after PM implantation. In total, 12 (6.9%) patients experienced LVEF > 10% decrease. Of 173 patients, 118 (68.2%) patients met criteria for LBBAP. The LBBAP group had a significantly lower incidence of PICM compared with the non-LBBAP group (log rank p = 0.048). The optimal V6RWPT for predicting PICM was 80 ms and the incidence of PICM increased in proportion to the increase in V6RWPT. In multivariate analysis, non-LBBA capture (HR: 5.58, 95% CI: 1.46–24.32; p = 0.01) and LVEF at pre-PM implant per 10% (HR: 0.11, 95% CI: 0.02–0.40; p = 0.0003) were independent predictors for the development of PICM. Conclusion: The incidence of PICM with LBBAP in paced patients undergoing PM implant with AVB and preserved LVEF is low. LBBA capture was associated with freedom from PICM.