The optimal pacing strategy for patients with atrioventricular block and preserved LVEF who require frequent ventricular pacing remains uncertain. The multicenter LEAP-Block randomized clinical trial evaluated whether LBBAP could improve clinical outcomes compared with conventional RVP. Conducted across 14 hospitals in China, the trial randomized 499 patients with LVEF of at least 50% and anticipated ventricular pacing burden greater than 40% to LBBAP (n=249) or RVP (n=250). The primary analysis included 482 patients, with a mean age of 67 years and 46% women.

At 24 months, the primary composite outcome of all-cause death, HF events, or upgrade to biventricular pacing occurred in 2.4% of the LBBAP group versus 12.5% of the RVP group (absolute risk difference, −10.1%; p=0.003). HF events were also lower with LBBAP (3.4% vs. 11.3%). The Kaplan-Meier estimated cumulative incidence of the…