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

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.