Conduction System Pacing Versus Biventricular Pacing in Cardiac Resynchronization Therapy

Introduction: Cardiac resynchronization therapy, also known as biventricular pacing, is an established treatment for heart failure with reduced ejection fraction. Conventional conduction system pacing, including his bundle pacing and left bundle branch area pacing, has emerged as an electrophysiological alternative technique to provide more effective ventricular activation. However, evidence from a randomized controlled trial remains limited. This study aims to compare the efficacy and safety of conduction system pacing versus biventricular pacing in patients undergoing CRT using evidence from randomized controlled trials. Research question: We sought to determine whether conduction conduction system pacing provides a better improvement in cardiac function and clinical outcome compared with conventional biventricular pacing in patients with heart failure undergoing cardiac resynchronization therapy based on evidence from randomized controlled trials. Methods: A systematic search was conducted across PubMed to identify randomised controlled trials comparing CSP with bi-ventricular pacing in patients with heart failure requiring CRT. Risk ratios (RR) with 95% confidence intervals (CI) were pooled using a random effects model. heterogeneity was assessed using I 2 statistics. Results: Across eight randomized trials, a total of 591 patients were analyzed (CSP=292, BiV=299). CBP demonstrated significantly lower risk of change in QRS duration [RR: -10.33 (-20.09, -0.57), p = 0.04], change in NYHA [RR: -0.11 (-0.15, -0.06), p=<0.00001]. However, no statistical significance was observed in change in LVEF [RR: 1.14 (-1.23, 3.58), p=0.34], all cause mortality [RR: 1.94, (0.62, 6.05), p=0.26], heart failure hospitalization [RR: 0.67, (0.22, 2.02), p=0.48], NYHA improvement by class 1 [RR: 1.07 (0.84, 1.37), p=0.59]. For procedural outcomes, no significant difference observed between groups for procedure time [RR: 2.16 (-15.36, 19.67), p=0.81], and lead capture threshold [RR: -0.11 (-0.39, 0.16), p=0.42]. Conclusion: In a randomized evidence comparing CRT strategies, conduction system pacing appears to provide superior improvement in change in QRS duration and NYHA class compared with biventricular pacing, while BiV does not yield potential clinical benefit in heart failure outcomes. Larger randomized trials with long term clinical endpoints are required to confirm effects.