Left bundle branch area pacing preserves left ventricular ejection fraction in patients with preserved systolic function: A comparison with right ventricular pacing and the influence of left bundle branch capture.

BACKGROUND

Left bundle branch area pacing (LBBAP), which includes left bundle branch pacing (LBBP) that captures the left bundle branch (LBB) and left ventricular septal pacing (LVSP) that does not, has been reported to improve clinical outcomes compared to right ventricular pacing (RVP). However, the clinical impact of LBB capture remains unclear.

OBJECTIVE

To compare the incidence of pacing-induced cardiomyopathy (PICM) and post-operative left ventricular ejection fraction (LVEF) between RVP and LBBAP in patients with normal pre-implantation LVEF, and to assess the impact of LBB capture.

METHODS

In this retrospective study, 273 patients with ≥20% ventricular pacing and pre-operative LVEF ≥50% were included. Patients were categorized into RVP (n=137) and LBBAP (n=110) groups. LBBAP was further divided into LBBP and LVSP based on the presence of LBB capture, determined by output-dependent QRS transition at final echocardiographic assessment. PICM was defined as an absolute LVEF decline >10% with a final LVEF <50%. ΔLVEF was calculated as the difference between pre-operative and 1-year post-operative LVEF.

RESULTS

With a mean follow-up of 49 ± 31 months in the RVP group and 24 ± 12 months in the LBBAP group, LBBAP was associated with significantly lower PICM incidence (log-rank p = 0.003) and smaller ΔLVEF decline (-7 ± 11% vs. -2 ± 8%, RVP vs. LBBAP, p < 0.01). No significant differences were observed between LBBP and LVSP in PICM incidence or ΔLVEF.

CONCLUSION

Regardless of LBB capture, LBBAP was associated with significantly lower PICM incidence and better LVEF preservation compared to RVP.