Long-Term Outcomes of Left Bundle-Branch Pacing vs Biventricular Pacing in Heart Failure: The HeartSync-LBBP Randomized Clinical Trial.

Summary

In 200 patients with HFrEF and LBBB, LBBP reduced the composite of all-cause death or heart failure hospitalization versus BiVP over a median 36 months (HR 0.26). All-cause mortality did not differ, but HF hospitalization and super-response rates favored LBBP.

Key Findings

• Primary composite of death or HF hospitalization was lower with LBBP vs BiVP (8% vs 28%; HR 0.26, 95% CI 0.12-0.57).
• HF hospitalization alone was reduced with LBBP (7% vs 28%; HR 0.23, 95% CI 0.10-0.52).
• Super-response (LVEF increase ≥15% or to ≥50%) occurred more often with LBBP (55% vs 36%).

Clinical Implications

For patients with HFrEF and LBBB undergoing CRT, LBBP may reduce HF hospitalizations and the composite of death/HFH compared with BiVP. Given opposing RCT findings in similar populations, centers should individualize approach, ensure operator expertise, and await confirmatory multicenter trials.

Limitations

• All sites in a single country may limit generalizability
• Open-label design and no significant difference in all-cause mortality

Future Directions

Head-to-head multinational RCTs with standardized implant techniques and crossover adjudication are needed to reconcile discordant CRT trials and define subgroups deriving maximal benefit from LBBP.