Amiodarone to prevent recurrence of atrial fibrillation

Background: The restoration and maintenance of sinus rhythm is a desirable goal in patients with atrial fibrillation, because the prevention of recurr ences can improve cardiac function and relieve symptoms. Uncontrolled studi es have suggested that amiodarone in low doses may be more effective and sa fer than other agents in preventing recurrence, but this agent has not been tested in a large, randomized trial. Methods: We undertook a prospective, multicenter trial to test the hypothes is that low doses of amiodarone would be more efficacious in preventing rec urrent atrial fibrillation than therapy with sotalol or propafenone. We ran domly assigned patients who had had at least one episode of atrial fibrilla tion within the previous six months to amiodarone or to sotalol or propafen one, given in an open-label fashion. The patients in the group assigned to sotalol or propafenone underwent a second randomization to determine whethe r they would receive sotalol or propafenone first; if the first drug was un successful the second agent was prescribed. Loading doses of the drugs were administered and electrical cardioversion was performed (if necessary) wit hin 21 days after randomization for all patients in both groups. The follow -up period began 21 days after randomization. The primary end point was the length of time to a first recurrence of atrial fibrillation. Results: Of the 403 patients in the study, 201 were assigned to amiodarone and 202 to either sotalol (101 patients) or propafenone (101 patients). Aft er a mean of 16 months of follow-up, 71 of the patients who were assigned t o amiodarone (35 percent) and 127 of those who were assigned to sotalol or propafenone (63 percent) had a recurrence of atrial fibrillation (P<0.001). Adverse events requiring the discontinuation of drug therapy occurred in 1 8 percent of the patients receiving amiodarone, as compared with 11 percent of those treated with sotalol or propafenone (P=0.06). Conclusions: Amiodarone is more effective than sotalol or propafenone for t he prevention of recurrences of atrial fibrillation. (N Engl J Med 2000;342 :913-20.) (C) 2000, Massachusetts Medical Society.