Meta-analysis finds conduction system pacing reduces heart failure hospitalizations in HFmrEF

OBJECTIVE: To compare the efficacy and safety of conduction system pacing (CSP) versus biventricular pacing (BiVP) in patients with heart failure with mildly reduced ejection fraction (HFmrEF). METHODS: A systematic review and meta-analysis was conducted according to PRISMA guidelines. PubMed, Embase, and Cochrane databases were searched through August 2025. Studies enrolling patients with HFmrEF (left ventricular ejection fraction 41%-49%) who underwent CSP (His-bundle pacing [HBP] or left bundle branch pacing [LBBP]) or BiVP were included. Outcomes assessed included all-cause mortality, heart failure hospitalization (HFH), composite endpoints (death + HFH), echocardiographic and electrical remodeling, functional status, and procedural/device complications. Risk of bias was evaluated, and evidence was graded using the GRADE framework. RESULTS: Seven studies (n = 1867 patients) met inclusion criteria. Pooled analysis showed CSP reduced HFH (HR 0.63, 95% CI 0.49-0.82) and improved the composite outcome of death or HFH (HR 0.64, 95% CI 0.43-0.94) compared with BiVP. Mortality was similar between groups (HR 0.82, 95% CI 0.63-1.07). CSP resulted in greater QRS narrowing (MD -14 ms) and consistent trends toward functional improvement. Device-related complications were numerically lower with CSP. CONCLUSION: CSP, particularly LBBP, appears superior to BiVP in reducing HFH and enhancing electrical resynchronization in HFmrEF. Large randomized trials are warranted to confirm these findings and establish CSP as a standard resynchronization strategy.