Conduction system vs. biventricular pacing in heart failure with reduced ejection fraction: a meta-analysis of randomized controlled trials.

AIMS: Conduction system pacing (CSP) has emerged as a physiologic alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP) in heart failure with reduced ejection fraction (HFrEF), yet its comparative effects remain uncertain. This meta-analysis sought to compare outcomes of CSP vs. BiVP in patients with HFrEF undergoing CRT. METHODS AND RESULTS: MEDLINE, Embase, Scopus, and the Cochrane Database were searched through 4 May 2026. Randomized controlled trials (RCTs) were synthesized using random-effects meta-analysis. Thirteen RCTs including 1320 participants were analysed (657 CSP, 663 BiVP). Conduction system pacing was associated with a lower risk of the composite of hospitalization for heart failure (HHF) or all-cause mortality compared with BiVP (46 vs. 83 events; odds ratio [OR] 0.51, 95% confidence interval [CI] 0.28-0.93). No significant differences were observed for HHF alone (OR 0.68, 95% CI 0.36-1.27) or all-cause mortality (OR 0.75, 95% CI 0.36-1.58). Conduction system pacing was associated with greater improvement in the 6-min walk distance (mean difference [MD] 21.53 m, 95% CI 4.33-38.73) and New York Heart Association functional class (standardized mean difference [SMD] -0.27, 95% CI -0.47 to -0.07), but not quality of life. Conduction system pacing also reduced QRS duration compared with BiVP (MD -10.94 ms, 95% CI -17.55 to -4.34), with no significant differences in left ventricular ejection fraction, left ventricular end-systolic volume, overall pacing threshold, total procedure time, fluoroscopy time, any complication, or reintervention. CONCLUSION: In patients with HFrEF undergoing CRT, CSP is associated with lower composite risk of HHF or all-cause mortality compared with BiVP. Conduction system pacing is also associated with improved functional capacity, without significant differences in safety or procedural outcomes.