Sex Differences in Left Bundle Branch Area Pacing Versus Biventricular Pacing for Cardiac Resynchronization Therapy

Background Women respond more favorably to biventricular pacing (BIVP) than men. Sex differences in atrioventricular and interventricular conduction have been described in BIVP studies. Left bundle branch area pacing (LBBAP) offers advantages due to direct capture of the conduction system. We hypothesized that men could respond better to LBBAP than BIVP. Objective To describe the sex differences in response to LBBAP vs. BIVP as the initial cardiac resynchronization therapy (CRT). Methods Multicenter prospective registry, we included patients with LVEF ≤35% and LBBB or an LVEF ≤40% with an expected RV pacing exceeding 40% undergoing initial CRT with LBBAP or BIVP. The composite primary outcome was heart failure-related hospitalization and all-cause mortality. The primary safety outcome included all procedure-related complications. Results There was no significant difference in the primary outcome when comparing men and women receiving LBBAP (p=0.46), whereas it was more frequent in men in the BIVP group than women treated with BIVP (p=0.03). The primary outcome occurred less frequently in men undergoing LBBAP (29.9%) compared to those treated with BIVP (46.5%) (p=0.004). In women, the incidence of the primary endpoint was 24.14% in the LBBAP group and 36.2% in the BIVP group, however this difference was not statistically significant (p=0.23). Complication rates remained consistent across all groups. Conclusion Men and women undergoing LBBAP for CRT had similar clinical outcomes. Men undergoing LBBAP demonstrated a lower risk of HF-related hospitalizations and all-cause mortality compared to men undergoing BIVP, while there was no difference between LBBAP and BIVP