Abstract 14258: Left Bundle Branch Pacing for Cardiac Resynchronization Therapy in Heart Failure: A Systematic Review and Meta-Analysis

Abstract

Introduction: : Cardiac resynchronization therapy (CRT) using a biventricular pacemaker (BVP) reduced mortality and rehospitalizations in patients with symptomatic heart failure (HF) with a left ventricular ejection fraction (LVEF) of less than 35% and concomitant left bundle branch block. However, 10-30% of BVP patients fail to show a clinical or echocardiographic response. Recently left bundle branch pacing (LBBP) has been studied as a more physiological alternative to BVP. The aim of this study is to summarize the available evidence on LBBP. Hypothesis: LBBP is an effective and feasible alternative option for CRT. Methods: Unrestricted searches of the PubMed, EMBASE, and Cochrane databases from inception till June 1, 2022, for studies examining the role of LBBP for CRT in HF patients. Data were analyzed using Revman 5.3 software. Mean Difference (MD), Odds Ratio (OR), and 95% Confidence interval (CI) were calculated using the random-effects model. Results: A total of 8 observational studies (3 single-armed, and 5 comparative studies) examined 756 HF patients who underwent CRT (551 LBBP vs 205 BVP). LBBP was successful in 87% of patients. Compared to baseline, LBBP was associated with a reduction in QRS duration (MD -53.5, 95%CI -69.77, -37.24), an increase in LVEF (MD 17%, 95%CI 13.38, 20.6), and a reduction in NYHA class (MD -1.4, 95%CI -1.56, -1.05). Compared to BVP, LBBP was associated with a significant reduction in QRS duration (MD -22.68, 95%CI -31, -14.35), improvement in LVEF (MD 7.58, 95%CI 5.21, 9.95), and a decrease in NYHA class (MD -0.55, 95% CI -0.73, -0.37) during a mean follow-up of 9.2 months. The super response rate, which is defined as an increase in LVEF of more than 20% or LVEF at or above 50% after CRT, was higher in LBBP compared to BVP (OR 2.98, 95%CI 1.65, 5.32). Conclusions: LBBP is a feasible and effective alternative for CRT. LBBP was associated with better electrical ventricular synchrony than BVP which was also translated into better echocardiographic and clinical outcomes in the short term. Our findings need to be further validated in larger randomized controlled trials with a long-term follow-up.