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

Abstract

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.