Comparison of β-blockers, amiodarone plus β-blockers, or sotalol for prevention of shocks from implantable cardioverter defibrillators -: The optic study.: A randomized trial

Context Implantable cardioverterdefibrillator (ICD) therapy is effective but is associated with high-voltage shocks that are painful. Objective To determine whether amiodarone plus beta-blocker or sotalol are better than beta-blocker alone for prevention of ICD shocks. Design, Setting, and Patients A randomized controlled trial with blinded adjudication of events of 412 patients from 39 outpatient ICD clinical centers located in Canada, Germany, United States, England, Sweden, and Austria, conducted from January 13, 2001, to September 28, 2004. Patients were eligible if they had received an ICD within 21 days for inducible or spontaneously occurring ventricular tachycardia or fibrillation. Intervention Patients were randomized to treatment for 1 year with amiodarone plus beta-blocker, sotalol alone, or beta-blocker alone. Main Outcome Measure Primary outcome was ICD shock for any reason., Results Shocks occurred in 41 patients (38.5%) assigned to beta-blocker alone, 26 (24.3%) assigned to sotalol, and 12 (10.3%) assigned to amiodarone plus beta-blocker. A reduction in the risk of shock was observed with use of either amiodarone plus beta-blocker or sotalol vs beta-blockeralone (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.28-0.68; P<.001). Amiodarone plus beta-blocker significantly reduced the risk of shock compared with beta-blocker alone (HR, 0.27; 95% Cl, 0.14-0.52; P<.001) and sotalol (HR, 0.43; 95% Cl, 0.22-0.85; P=.02). There was a trend for sotalol to reduce shocks compared with beta-blocker alone (HR, 0.61; 95% C1, 0.37-1.01; P=.055). The rates of study drug discontinuation at 1 year were 18.2% for amiodarone, 23.5% for sotalol, and 5.3% for beta-blocker alone. Adverse pulmonary and thyroid events and symptomatic bradycardia were more common among patients randomized to amiodarone. Conclusions Despite use of advanced ICD technology and treatment with a beta-blocker, shocks occur commonly in the first year after ICD implant. Amiodarone plus beta-blocker is effective for preventing these shocks and is more effective than sotalol but has an increased risk of drug-related adverse effects.