Is continuous or episodic prophylactic treatment with amidarone safer and more effective for the prevention of atrial fibrillation in adults?

Atrial fibrillation is less likely to recur in adults receiving continuous rather than episodic amiodarone treatment. There were no differences in major adverse events between treatment groups. (LOE = 1b-)

Ahmed S, Rienstra M, Crijns HJ, et al, for the CONVERT Investigators. Continuous vs episodic prophylactic treatment with amiodarone for the prevention of atrial fibrillation. A randomized trial. JAMA 2008;300(15):1784-1792.  [PMID:18854540]

Randomized controlled trial (double-blinded)

Industry + govt

Uncertain

Outpatient (specialty)

Amiodarone is effective at preventing recurrence of atrial fibrillation but it also frequently results in noncardiac adverse events. These investigators identified 214 adults with a mean age 67 years and recurrence of symptomatic persistent atrial fibrillation or atrial flutter of less than 1 year's duration. After anticoagulation and a 4-week loading period of amiodarone (600 mg daily), all patients not otherwise in sinus rhythm underwent electrical cardioversion. After cardioversion, amiodarone was lowered to a dose of 200 mg daily. Patients then randomly received continued amiodarone (continuous treatment) or had their amiodarone treatment discontinued 4 weeks after randomization and only restarted with recurrence of atrial fibrillation (episodic treatment). Individuals assessing all outcomes remained masked to treatment group assignment. Follow-up occurred for 98% of patients for a mean of 2.1 years. Using intention-to-treat analysis, atrial fibrillation requiring treatment recurred significantly less often in the continuous group than in the episodic treatment group (54% vs 80%; number needed to treat = 4; 95% CI, 3-6). There was also a significantly increased rate of the composite outcome of all-cause mortality and cardiovascular hospitalizations with episodic treatment compared with continuous treatment (53% vs 34%).