Clinical and electrical outcomes of conduction system pacing versus right ventricular pacing in atrioventricular block: a systematic review and meta-analysis

Introduction Right ventricular pacing (RVP) is the conventional treatment for atrioventricular (AV) block, but may cause ventricular dyssynchrony and adverse remodeling. Conduction system pacing (CSP) has emerged as a physiologic alternative. This meta-analysis compared the efficacy, safety, echocardiographic, and electrical outcomes of CSP versus RVP in patients with AV block. Methods From 2,688 records identified in PubMed, Cochrane, Embase, and ScienceDirect, 19 studies were included. Pooled efficacy, safety, echocardiographic, and procedural outcomes were analyzed using a random-effects model in R (v4.5.1), with meta-regression assessing follow-up effects; p < 0.05 was considered significant. Results Nineteen studies comprising 5,390 patients (2,182 CSP; 3,208 RVP) were analyzed. Compared with RVP, CSP was associated with a reduction in all-cause mortality (RR 0.50, p < 0.0001), heart failure hospitalization (RR 0.39, p < 0.0001), pacing-induced cardiomyopathy (RR 0.36, p = 0.039), and the primary composite outcome (RR 0.44, p < 0.0001). Cardiovascular death, cardiac resynchronization therapy upgrade, and biventricular pacing upgrade did not differ significantly between groups. CSP was associated with improved left ventricular ejection fraction (MD +2.60%, p < 0.0001) and reduced left ventricular end-diastolic diameter (MD −1.54 mm, p < 0.0001) compared with RVP. Shorter paced QRS duration at implantation and follow-up was observed with CSP compared with RVP, indicating superior ventricular synchrony, although procedural and fluoroscopy times were longer. Meta-regression indicated that LVEF improvement decreased with longer follow-up, while LVEDD reduction remained consistent. Conclusion CSP was associated with lower all-cause mortality, HF hospitalization, and pacing-induced cardiomyopathy, while improving ventricular function without additional device-related complications compared with RVP; however, these findings should be interpreted in the context of predominantly observational data.