Mid-term clinical outcomes of left bundle branch area pacing compared to accurate right ventricular septal pacing

Abstract Background Although left bundle branch area pacing (LBBAP) reportedly results in fewer adverse outcomes after implantation than conventional stylet-guided right ventricular septal pacing (RVSP), previous studies have not compared LBBAP with accurate RVSP using a delivery catheter. The aim of this study was to compare clinical outcomes between LBBAP and accurate RVSP among patients with atrioventricular block (AVB). Methods This single-center observational study enrolled 160 patients requiring RV pacing due to symptomatic AVB between September 2018 and December 2021. Primary composite outcomes included all-cause death, hospitalization due to heart failure (HF), and upgrading to biventricular pacing. Secondary composite outcomes included any procedural and postprocedural complications. Results Overall, 160 patients were analyzed (LBBAP, n = 81; RVSP, n = 79). No significant differences in baseline characteristics were observed between the two groups. The RV pacing burden at 1 year after implantation was 90.8% ± 20.4% and 86.2% ± 22.6%, respectively ( p = 0.21). During a mean follow-up of 840 ± 369 days, the incidence of the primary outcome was significantly lower with LBBAP (4.9%) compared to RVSP (22.8%) (Log-rank p = 0.02). There was no significant difference in the incidence of the secondary outcome between the two groups (3.7% vs. 5.1%, p = 0.65). In the multivariate analysis, baseline QRS duration, RV pacing burden, and LBBAP were independently associated with the primary outcome (baseline QRS duration: hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00–1.02; p < 0.001; RV pacing burden: HR, 1.01; 95% CI, 1.00–1.02; p < 0.001; LBBAP: HR, 0.45; 95% CI, 0.31–0.64; p < 0.001). Conclusion In patients requiring frequent RV pacing, LBBAP was associated with reduced adverse clinical outcome compared to accurate RVSP using a delivery catheter. Graphical Abstract