HeartSync Trial: LBBP Cuts Heart Failure Hospitalizations vs BiVP

The HeartSync-LBBP randomized clinical trial, published in JAMA Cardiology, found that left bundle-branch pacing (LBBP) significantly outperformed conventional biventricular pacing (BiVP) in reducing combined death and heart failure hospitalization among patients with left bundle-branch block and severely reduced ejection fraction. The multicenter study enrolled 200 patients across six Chinese centers between October 2020 and September 2024, with a median 36-month follow-up. All participants had an LVEF of 35% or lower and were randomized 1:1 to each pacing strategy. The primary outcome, time to all-cause death or heart failure hospitalization, occurred in 8% of the LBBP group versus 28% in the BiVP group, a substantial difference. Heart failure hospitalizations specifically were 7% versus 28%, while all-cause mortality trended lower under LBBP (2% vs. 5%) without reaching statistical significance. LBBP works by directly engaging the heart's native conduction system, offering a more physiological activation pattern than BiVP's epicardial approach. A higher proportion of LBBP patients achieved "super response," meaning marked LVEF improvement. Generalizability is constrained by an exclusively Chinese cohort, a high proportion of nonischemic cardiomyopathy, and procedures performed at high-volume experienced centers.