Left Bundle Branch Area Pacing Compared With Biventricular Pacing for Cardiac Resynchronization Therapy in Patients With Left Ventricular Ejection Fraction ≤50%: Results from the International Collaborative LBBAP Study (I-CLAS)

Authors

• Ramez Morcos
• Pugazhendhi Vijayaraman
• Óscar Cano
• Francesco Zanon
• Shunmuga Sundaram Ponnusamy
• Bengt Herweg
• Parikshit S Sharma
• Marek Jastrzebski
• Manuel Molina-Lerma
• Zachary I Whinnett
• Kevin Vernooy
• Jiangang Zou
• Girish M Nair
• Rajeev K Pathak
• Roderick Tung
• Gaurav A Upadhyay
• Karol Curila
• Mihail G Chelu
• Kenneth A Ellenbogen

Language

English

Publication Date

8-1-2025

Journal

Heart Rhythm

DOI

10.1016/j.hrthm.2025.04.005

PMID

40288475

PMCID

PMC13251317

PubMedCentral® Posted Date

6-11-2026

PubMedCentral® Full Text Version

Author MSS

Abstract

Background: Cardiac resynchronization therapy (CRT) with biventricular pacing (BVP) is an established treatment of heart failure with reduced ejection fraction and wide QRS. Left bundle branch area pacing (LBBAP) has emerged as a physiologic alternative by directly engaging the His-Purkinje system, potentially improving electrical resynchronization and clinical outcomes.

Objective: The aim of the study was to compare the clinical outcomes between BVP and LBBAP in patients with left ventricular ejection fraction (LVEF) ≤50% undergoing CRT.

Methods: This multicenter observational study included patients with LVEF ≤50% receiving CRT with either LBBAP or BVP at 18 centers from January 2018 to June 2023. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization (HFH). Secondary outcomes included separate analyses of HFH and all-cause mortality. Propensity score matching was used to balance baseline characteristics. Kaplan-Meier curves, Cox proportional hazards models, and competing risk analyses were performed.

Results: A total of 2579 patients were included (BVP, 1118; LBBAP, 1461). In the propensity score-matched cohort (BVP, 780; LBBAP, 780), LBBAP demonstrated shorter paced QRS duration (129 ± 19 ms vs 143 ± 22 ms; P < .001). LBBAP was associated with a significantly lower risk of the composite primary outcome (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.66-0.98; P = .048) and reduced HFH (HR, 0.63; 95% CI, 0.49-0.82; P < .001). No significant difference in all-cause mortality was observed (HR, 0.82; 95% CI, 0.63-1.07; P = .156). Procedural complications were lower with LBBAP (3.5% vs 6.5%, P = .004).

Conclusion: LBBAP was associated with superior electrical resynchronization, fewer HFHs, and lower procedural complications compared with BVP in patients with LVEF < 50% requiring CRT. Randomized trials are needed to confirm long-term benefits.

Keywords

Humans, Male, Female, Cardiac Resynchronization Therapy, Stroke Volume, Heart Failure, Aged, Ventricular Function, Left, Bundle of His, Treatment Outcome, Retrospective Studies, Middle Aged, Follow-Up Studies, Cardiac resynchronization therapy, Left bundle branch area pacing, Biventricular pacing, Heart failure hospitalization, Mortality

Published Open-Access

yes

Recommended Citation

Morcos, Ramez; Vijayaraman, Pugazhendhi; Cano, Óscar; et al., "Left Bundle Branch Area Pacing Compared With Biventricular Pacing for Cardiac Resynchronization Therapy in Patients With Left Ventricular Ejection Fraction ≤50%: Results from the International Collaborative LBBAP Study (I-CLAS)" (2025). Faculty, Staff and Students Publications. 6858.
https://digitalcommons.library.tmc.edu/baylor_docs/6858