Conduction System Pacing Versus Biventricular Pacing for Cardiac Resynchronization Therapy in Patients with Heart Failure with Reduced Ejection Fraction and Left Bundle Branch Block: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with GRADE Assessment and Trial Sequential Analysis

This systematic review and meta-analysis compares conduction system pacing (CSP) with conventional biventricular pacing (BiVP) for cardiac resynchronization therapy in adults with heart failure with reduced ejection fraction (HFrEF) and left bundle branch block (LBBB). The review is restricted to parallel-group randomized controlled trials with separately extractable data for the target population. The primary outcomes are changes in left ventricular ejection fraction (LVEF) at 6 and 12 months. Secondary outcomes include left ventricular end-systolic volume, echocardiographic response, paced QRS duration, 6-minute walk distance, procedure and fluoroscopy duration, crossover during implantation, heart failure hospitalization, and all-cause mortality. Time-to-event outcomes are considered separately from crude event counts. Risk of bias is assessed using RoB 2, certainty of evidence using GRADE, and trial sequential analysis is performed for the 6- and 12-month LVEF outcomes. The aim is to determine whether CSP provides better ventricular remodeling or other clinical or procedural outcomes than BiVP in this specific patient population.