Systematic review and meta-analysis of randomised trials only — 5 RCTs with 985 patients with atrioventricular (AV) block — comparing conduction system pacing (CSP) with conventional right ventricular pacing (RVP). The composite endpoint significantly favoured CSP (HR 0.54; 95% CI 0.31-0.95; p=0.03), with markedly reduced risk of HF hospitalisation (RR 0.30; 95% CI 0.17-0.54; p<0.0001). No significant difference in all-cause mortality (RR 0.69; 95% CI 0.36-1.30; p=0.25). Secondary outcomes: significantly greater LVEF improvement (p=0.008) and shorter QRS duration (p=0.002) with CSP. In AV block, CSP therefore yields cardiac and clinical benefit over RVP — mainly through reduced HF hospitalisation and preservation of physiological activation. Mortality evidence remains uncertain. A practice shift toward CSP in pacemaker selection is supported by these data.
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.
This study aimed to assess the clinical outcomes of CSP versus RVP in patients with AVB based exclusively on randomised controlled trials (RCTs).
MEDLINE, Embase and Cochrane were searched from inception to October 2025. Clinical outcomes comparing CSP and RVP were analysed using HR, risk ratio (RR) and mean difference with 95% CIs. Heterogeneity was assessed with I2 and robustness tested by sensitivity analyses. Outcomes included heart failure hospitalisation (HFH), all-cause mortality (ACM), composite endpoint and key cardiac parameters.
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.
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.
