Conduction system pacing versus biventricular pacing in patients with heart failure and left bundle branch block: a systematic review and meta-analysis

BACKGROUND: Heart failure (HF) with left bundle branch block (LBBB) is associated with adverse clinical outcomes. Although biventricular pacing (BVP) remains the standard therapy, up to 30% of patients show suboptimal response. Conduction system pacing (CSP), including His bundle pacing (HBP) and left bundle branch pacing (LBBP), provides more physiological ventricular activation, but comparative evidence remains limited. This study aimed to analyze available data comparing HBP or LBBP with BVP in patients with HF and LBBB, focusing on electrophysiological, echocardiographic, and clinical outcomes. METHODS: A systematic search of PubMed, Embase, Cochrane, ESC and EHRA databases identified studies comparing BVP with HBP or LBBP. Data extraction and synthesis followed PRISMA guidelines, and risk of bias was assessed using the Newcastle-Ottawa Scale and Cochrane ROB-2 tool. RESULTS: Eighteen studies (14 observational and 4 RCTs) involving 1375 BVP, 135 HBP, and 1080 LBBP procedures were analyzed. Compared to BVP, LBBP resulted in QRS reduction (MD: -22.60 ms, 95% CI: -28.54 to -16.67), LVEF improvement (MD: 4.41%, 95% CI: 2.65 to 6.18), LVEDD reduction (MD: -2.62 mm, 95% CI: -5.96 to 0.72), NYHA functional class improvement (MD: -0.44, 95% CI: 0.97 to 0.10), lower HF hospitalization (RR: 0.51, 95% CI: 0.40-0.64) and lower all-cause mortality (RR: 0.65, 95% CI: 0.44-0.96). In contrast, HBP only showed improved in LVEF (MD: 12.13%, 95% CI: 0.15-24.10), while other outcomes remained inconclusive. CONCLUSION: LBBP offers superior electrophysiological and clinical outcomes compared with BVP, supporting its role as a more physiological pacing strategy.