Short-Term Versus Long-Term Antiarrhythmic Drug Treatment After Cardioversion of Atrial Fibrillation (Flec-SL): A Prospective, Randomized, Open-Label, Blinded Endpoint Assessment Trial

Study Questions:

Is short-term treatment for 4 weeks with flecainide as effective as long-term treatment with flecainide for 6 months for preventing recurrent atrial fibrillation (AF) after cardioversion?


Following successful cardioversion of AF, 635 patients (mean age 64 years) were randomly assigned to no antiarrhythmic therapy (n = 81), short-term flecainide therapy (n = 273), or long-term flecainide therapy (n = 281). The flecainide dose was 200-300 mg/day. The patients were followed for 6 months with daily telemetric recordings. The primary outcome was first recurrence of persistent AF.


Enrollment in the control group was stopped at 4 weeks because of a higher recurrence rate (48%) than in the flecainide groups (30%). During the remainder of the study, the AF recurrence rate was higher in the short-term treatment group (46%) than in the long-term treatment group (39%).


The authors concluded that after transthoracic cardioversion of AF, 6 months of treatment with flecainide prevents recurrent AF more effectively than does 4 weeks of treatment.


The rationale for the study design was that short-term therapy with a rhythm-control agent might be sufficient to prevent long-term recurrences of AF after cardioversion by allowing for reversal of electrical remodeling during the first 4 weeks after resumption of sinus rhythm. But rhythm control agents such as flecainide also can prevent AF by suppressing triggers (such as ectopy from the pulmonary vein muscle sleeves), explaining why long-term antiarrhythmic drug therapy was found to be more effective than short-term therapy after cardioversion.

Clinical Topics: Arrhythmias and Clinical EP, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Recurrence, Atrial Fibrillation, Flecainide

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