Mission

Researchers are evaluating the effects of two beta-blockers, carvedilol and metoprolol succinate, in patients with heart failure with reduced ejection fraction (HFrEF) who have an implantable cardioverter defibrillator (ICD). This multicenter, open-label, randomized clinical trial, called CARVTOP-ICD, will enroll 2,000 participants across 100 U.S. sites. The study includes an 18-month feasibility phase with 100 participants from 15 sites to assess study processes and patient engagement. The goal is to compare clinical outcomes and provide evidence to guide beta-blocker choice in this patient population. Participants currently treated with metoprolol succinate and having an ICD implanted for primary prevention will be randomly assigned in a 1:1 ratio to either continue metoprolol succinate or switch to an equivalent dose of carvedilol. Both drugs will be titrated to the maximum tolerated dose as per the study protocol. The feasibility phase focuses on recruitment, medication switching, safety, adherence, and retention. After randomization, participants will be followed for up to 3 years with regular assessments, including medication adherence and quality of life. Participants will receive assessments at baseline, 2 and 4 weeks, and quarterly visits thereafter. Evaluations include ICD interrogations, cardiac imaging, laboratory tests, heart failure classification, medication use, adverse events, and patient-reported outcomes through questionnaires. The main outcome measured is the first occurrence of ICD therapy, cardiovascular hospitalization, or cardiovascular death within 3 years. Secondary outcomes include ICD shock burden, healthcare utilization, and quality of life. The study will also analyze subgroups by sex, age, race, heart failure cause, ICD type, and heart function.