Multicenter Randomized Trial Comparing Amiodarone to Implantable Defibrillator in Patients With Nonischemic Cardiomyopathy and Asymptomatic Nonsustained Ventricular Tachycardia: AMIOVIRT Trial
Introduction. Patients (pts) with nonischemic dilated cardiomyopathy (NIDCM) and asymptomatic (asx) nonsustained ventricular tachycardia (NSVT) are at high risk for sudden cardiac death. Amiodarone or an implantable defibrillator (ICD) may reduce mortality in this patient group. Therefore, the purpose of this multicenter, randomized trial was to compare the total mortality rate associated with amiodarone to ICD therapy in patients with NIDCM and asx NSVT. Methods. Pts with NIDCM, left ventricular ejection fraction < 0.35, and asx NSVT were eligible for study participation. 102 pts were randomized to receive either amiodarone or ICD therapy. 75 pts were followed in a study registry. Because there were no identifiable differences in clinical characteristics between randomized and registry pts, all pts were grouped according to initial therapy, irrespective of whether they were randomized or were followed in the study registry. The pts were 59±12 yrs, 29% were women, the left ventricular ejection fraction (LVEF) was 0.22±0.08, 85% had either NYHA Class II or III heart failure, and the mean follow-up was 20.1±12.6 months. The primary study endpoint was total mortality. The study was designed to achieve 80% power to identify a reduction in total mortality from 20% to 10% (219 patients in each group). Stopping rules included a mortality difference associated with a p < 0.025, or p ≥ 0.05 (90% power) when the data were extrapolated to 600 patients. Results. The stopping rule for futility was reached, and the study was stopped early. The percent of patients surviving at 2 years (88% vs 89%) and 4 years (85% vs 79%) in the amiodarone and ICD treatment groups, respectively, were similar (p=0.6). Conclusions. In pts with NIDCM, LVEF <0.35, and asx NSVT the total mortality rate at 4 years is the same in pts treated with Amiodarone or an ICD.
- Copyright © 2000 by American Heart Association