Comparative clinical outcomes of left bundle branch vs. right ventricular septal and apical pacing: insights from a tertiary centre

Left bundle branch area pacing (LBBAP) is emerging as a promising alternative to conventional right ventricular (RV) pacing. Despite its potential, LBBAP has not fully replaced traditional methods. There remains a significant need for more comprehensive data to evaluate its clinical efficacy.

This retrospective study aimed to compare clinical outcomes of patients who underwent LBBAP with those who received conventional RV pacing, either septal or apical, through survival analysis.

A cohort of patients who underwent pacemaker implantation between September 2022 and January 2025 was retrospectively evaluated. Baseline data, including pacemaker type, medication use, and comorbid conditions, were recorded. The composite endpoint included admission to the emergency room for acute heart failure, hospitalization for acute heart failure, a decrease in left ventricular ejection fraction (LVEF), or death. Time to event was documented. Chi-squared tests were utilized for categorical variable analyses. Pacemaker type and other significant variables identified from the previous analyses were then included in a multivariate Cox regression model to adjust for potential confounders. Further adjustment was made for pacing below and above 40%.

The study analysed a total of 1,095 patients, with 337 (30.8%) undergoing LBBAP and 758 (69.2%) receiving conventional RV pacing (septal: 437 (39.9%), apical: 321 (29.3%). The cohort consisted of 684 men (62.5%) and 411 women (37.5%), with a mean age of 78.07 years (SD ± 0.775). The median follow-up period was 457 days (IQR 199.25-639.25). The composite endpoint occurred in 197 patients (18%). Chi-squared tests identified sex, previous valvular surgery, and the use of angiotensin receptor-neprilysin inhibitors (ARNI) and mineral receptor antagonists (MRA) as significant variables. In the multivariate analysis, pacemaker type was significant, with RV septal and RV apical pacing showing increased risks compared to LBBAP (p=0.038 and p=0.030, respectively). Hazard ratios were 1.706 (95% CI 1.030-2.827) for RV septal and 1.787 (95% CI 1.056-3.022) for RV apical pacing. Other significant predictors included age, previous valvular surgery and use of ARNI, which maintained significance in the multivariate Cox regression model.

This study demonstrated significant differences in clinical outcomes among patients receiving LBBAP compared to those with conventional RV apical and septal pacing, even after adjusting for significant covariates. The results strongly suggest that LBBAP could offer a preferable alternative to traditional RV pacing techniques, highlighting the need for further prospective studies to validate these benefits and potentially redefine pacing strategies in clinical practice.