Incidence of pacing-induced cardiomyopathy: left bundle branch area pacing versus leadless pacing.

Background: Patients with chronic right ventricular (RV) pacing are at risk for developing pacing-induced cardiomyopathy (PICM). Data regarding the incidence of PICM when pacing the RV septum using a leadless pacemaker (LP) are limited. Left bundle branch area pacing (LBBAP) has emerged as a viable alternative to RV pacing with a low incidence of PICM.

Methods: All patients who received either a LP capable of providing atrioventricular (AV) synchronous pacing or a permanent pacemaker (PPM) with a LBBAP lead (lumenless or stylet-driven leads) for AV block between January 2021 and January 2023 at a single center were screened. Patients were included in the final analysis if they had both a pre- and post-operative transthoracic echocardiogram, pre- and post-operative electrocardiograms, and a pacing burden of ≥ 20%. The incidence of PICM, defined as a decrease in the left ventricular ejection fraction (LVEF) by ≥ 20% and to a value < 50% after a follow-up of at least six months, was compared between LBBAP and LP groups.

Results: Over the study period, 533 PPMs were implanted for AV block. Of these, 95 patients met the inclusion criteria; 70 underwent LBBAP and 25 received LPs. The average age of the population was 75 ± 13 years; 64 (63%) were men. There was no difference in the mean pre-operative LVEF (57% ± 16% vs. 61% ± 10%; p = 0.25) or QRS duration (123 ± 33ms vs. 130 ± 29ms) between the LBBAP and LP groups. There was a high burden of ventricular pacing in both groups (90% ± 19% vs. 92% ± 13%; p = 0.52). After a follow-up of 14 ± 8 months, the incidence of PICM was significantly lower in the LBBAP group compared to the LP group (4.3% vs. 24%; p = 0.0039).

Conclusion: In patients who are not candidates for cardiac resynchronization, who require a high burden of ventricular pacing, LBBAP may lead to a lower incidence of PICM than right ventricular septal pacing with a LP.