Clinical outcomes of left bundle branch area pacing compared to right ventricular pacing: Results from the Geisinger-Rush Conduction System Pacing Registry

BACKGROUND Left bundle branch area pacing (LBBAP) has been shown to be a feasible option for patients requiring ventricular pacing. OBJECTIVE The purpose of this study was to compare clinical outcomes between LBBAP and RVP among patients undergoing pacemaker implantation METHODS This observational registry included patients who underwent pacemaker implantations with LBBAP or RVP for bradycardia indications between April 2018 and October 2020. The primary composite outcome included all-cause mortality, heart failure hospitalization (HFH), or upgrade to biventricular pacing. Secondary outcomes included the composite endpoint among patients with a prespecified burden of ventricular pacing and individual outcomes. RESULTS A total of 703 patients met inclusion criteria (321 LBBAP and 382 RVP). QRS duration during LBBAP was similar to baseline (121 +/- 23 ms vs 117 +/- 30 ms; P = .302) and was narrower compared to RVP (121 +/- 23 ms vs 156 +/- 27 ms; P <.001). The primary composite outcome was significantly lower with LBBAP (10.0%) compared to RVP (23.3%) (hazard ratio [HR] 0.46; 95%T confidence interval [CI] 0.306-0.695; P <.001). Among patients with ventricular pacing burden >20%, LBBAP was associated with significant reduction in the primary outcome compared to RVP (8.4% vs 26.1%; HR 0.32; 95% CI 0.187-0.540; P <.001). LBBAP was also associated with significant reduction in mortality (7.8% vs 15%; HR 0.59; P = .03) and HFH (3.7% vs 10.5%; HR 0.38; P = .004). CONCLUSION LBBAP resulted in improved clinical outcomes compared to RVP. Higher burden of ventricular pacing (>20%) was the primary driver of these outcome differences.