Clinical outcomes of conduction system pacing versus right ventricular pacing in patients with atrioventricular block: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Conduction system pacing (CSP) has emerged as an alternative to right ventricular pacing (RVP) for atrioventricular block (AVB) aiming to avoid ventricular dyssynchrony and adverse heart failure outcomes yet clinical adoption remains limited due to insufficient randomised evidence. OBJECTIVES: This study aimed to assess the clinical outcomes of CSP versus RVP in patients with AVB based exclusively on randomised controlled trials (RCTs). METHODS: and robustness tested by sensitivity analyses. Outcomes included heart failure hospitalisation (HFH), all-cause mortality (ACM), composite endpoint and key cardiac parameters. RESULTS: Data from five RCTs involving 985 patients with AVB were analysed. In the pooled analysis, the composite endpoint is significantly improved in the intervention pacing (HR=0.54; 95% CI 0.31 to 0.95; p=0.03), similarly with markedly reduced risk for HFH (RR=0.30; 95% CI 0.17 to 0.54; p<0.0001). However, no significant difference was observed between CSP and RVP in ACM (RR=0.69; 95% CI 0.36 to 1.30; p=0.25). Secondary outcomes significantly favoured the CSP group, as the change in left ventricular ejection fraction (LVEF) was significantly increased (p=0.008) and the QRS duration was significantly shorter (p=0.002) compared with RVP. CONCLUSION: In patients with AVB, CSP provides enhanced cardiac and clinical benefit compared with RVP driven by reduced HFH, improved LVEF and shorter QRS, while evidence regarding its influence on overall mortality remains uncertain.