Upgrade of right ventricular pacing to cardiac resynchronization therapy in heart failure: a randomized trial

Abstract

Background and De novo implanted cardiac resynchronization therapy with defibrillator (CRT-D) reduces the risk of morbidity and mortality Aims in patients with left bundle branch block, heart failure and reduced ejection fraction (HFrEF). However, among HFrEF patients with right ventricular pacing (RVP), the efficacy of CRT-D upgrade is uncertain. Methods In this multicentre, randomized, controlled trial, 360 symptomatic (New York Heart Association Classes II–IVa) HFrEF patients with a pacemaker or implantable cardioverter defibrillator (ICD), high RVP burden ≥ 20%, and a wide paced QRS complex duration ≥ 150 ms were randomly assigned to receive CRT-D upgrade (n = 215) or ICD (n = 145) in a 3:2 ratio. The primary outcome was the composite of all-cause mortality, heart failure hospitalization, or <15% reduction of left ventricular end-systolic volume assessed at 12 months. Secondary outcomes included all-cause mortality or heart failure hospitalization. Results Over a median follow-up of 12.4 months, the primary outcome occurred in 58/179 (32.4%) in the CRT-D arm vs. 101/128 (78.9%) in the ICD arm (odds ratio 0.11; 95% confidence interval 0.06–0.19; P