Low-dose amiodarone in severe chronic heart failure

Sudden cardiac death is a common cause of mortality in patients with congestive heart failure. Asymptomatic ventricular arrhythmia has been attributed as the cause for increased overall mortality in such patients. We conducted a prospective randomised single-blind placebo-controlled trial with low-dose amiodarone to assess its efficacy in reducing mortality in severe congestive heart failure and its effect on exercise tolerance, left ventricular systolic function and ventricular ectopic activity. Patients were randomised to receive amiodarone (n = 36) 400 mg/day orally for one month followed by a maintenance dose of 200 mg/day, or to a standard treatment (n = 40) according to intention-to-treat principle. There were 10 cardiac deaths in the amiodarone-treated group and 16 in the control group. Significant improvement was noted in exercise time in the treadmill test (modified Bruce Protocol) among patients in the amiodarone-treated group while no such statistical difference was detectable in the placebo group. Side-effects in the amiodarone group included asymptomatic rise in hepatic enzymes (three-fold) in 6 percent and proarrhythmia in 3 percent of patients. Nausea was reported in one patient and rash in one. Though low-dose amiodarone proved to be an effective antiarrhythmic agent, it failed to live up to the expectation of improving sudden cardiac death in patients with severe chronic heart failure and asymptomatic ventricular ectopy.