Conduction System Pacing Versus Right Ventricular Pacing in Patients with Atrioventricular Block and Anticipated High Pacing Burden

Right ventricular pacing (RVP) in patients with atrioventricular (AV) block and high anticipated pacing burden is associated with pacing-induced cardiomyopathy (PICM) in approximately 12% to 20% of patients, whereas conduction system pacing (CSP) preserves more physiologic ventricular activation and may mitigate these consequences; the totality of contemporary randomized evidence has not been systematically pooled. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing CSP with RVP in patients with AV block or anticipated high ventricular pacing burden and a minimum 6-month follow-up, with co-primary outcomes of PICM incidence and change in left ventricular ejection fraction (ΔLVEF) and secondary outcomes of heart failure hospitalization (HFH), all-cause mortality, composite clinical endpoint, and paced QRS duration (PROSPERO CRD420261400227); random-effects meta-analysis used DerSimonian-Laird estimation. Five RCTs (LBBP-FAVOUR, CSPACE, Prague CSP, PACE-HF, STAY; N=806) met inclusion criteria. CSP significantly reduced PICM (hazard ratio [HR] 0.30, 95% confidence interval [CI] 0.18-0.48; p<0.001; I²=0%; k=4), was associated with greater LVEF preservation (pooled mean difference [MD] +4.41%, 95% CI +1.82 to +6.99; p=0.001; I²=87%; k=5), and reduced HFH (HR 0.24, 95% CI 0.12-0.48; p<0.001; I²=0%; k=5). CSP shortened paced QRS duration (MD -27.5 ms, 95% CI -32.6 to -22.5; p<0.001; k=5). All-cause mortality was numerically lower with CSP but did not reach significance (HR 0.57, 95% CI 0.29-1.12; p=0.10; k=4). In a prespecified sensitivity analysis restricting to multicenter trials with N≥150, all findings were concordant with the primary analysis. In conclusion, CSP substantially reduces PICM, preserves LVEF, and reduces HFH compared with RVP in patients with AV block and anticipated high pacing burden, supporting its consideration as the preferred pacing strategy in appropriately selected patients.