Conduction System Pacing Versus Biventricular Cardiac Resynchronization in HFmrEF: A Systematic Review and...

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Management

Background:

• Heart failure with mildly reduced ejection fraction (HFmrEF) affects a significant patient population.
• Current pacing strategies like biventricular pacing (BiVP) aim to improve cardiac function but have limitations.
• Conduction system pacing (CSP) offers a potentially more physiological approach to cardiac resynchronization.

Purpose of the Study:

• To compare the efficacy and safety of CSP (His-bundle pacing [HBP] and left bundle branch pacing [LBBP]) versus BiVP in patients with HFmrEF.
• To evaluate outcomes including mortality, heart failure hospitalizations (HFH), and electrical remodeling.
• To assess functional status and procedural complications associated with both pacing methods.

Main Methods:

• Systematic review and meta-analysis adhering to PRISMA guidelines.
• Searched PubMed, Embase, and Cochrane databases up to August 2025.
• Included seven studies with 1867 patients diagnosed with HFmrEF (LVEF 41%-49%) undergoing CSP or BiVP.

Main Results:

• CSP significantly reduced HFH (HR 0.63) and the composite endpoint of death or HFH (HR 0.64) compared to BiVP.
• No significant difference in all-cause mortality was observed between CSP and BiVP (HR 0.82).
• CSP led to greater QRS narrowing (MD -14 ms) and showed trends toward improved functional status with numerically lower device-related complications.

Conclusions:

• CSP, especially LBBP, demonstrates superiority over BiVP in reducing HFH and improving electrical resynchronization in HFmrEF patients.
• The findings suggest CSP may be a more effective resynchronization strategy for this population.
• Large randomized controlled trials are recommended to validate these results and establish CSP as a standard of care.