n-3 Polyunsaturated fatty acids for the prevention of arrhythmia recurrence after electrical cardioversion of chronic persistent atrial fibrillation: a randomized, double-blind, multicentre study

AIMS: Persistent atrial fibrillation (AF) often recurs after direct current electrical cardioversion (ECV). As several experimental and clinical studies suggest that n-3 polyunsaturated fatty acids (PUFAs) may have antiarrhythmic properties even at the atrial level, we aimed to evaluate whether oral supplementation with PUFAs, in addition to conventional antiarrhythmic drugs, could reduce the recurrence rate of the arrhythmia after ECV of persistent AF. METHODS AND RESULTS: Two hundred and four patients (mean age 69.3 years, 33% females) with persistent AF were randomly assigned to receive 3 g/day of PUFAs until ECV and 2 g/day thereafter (104 patients) or placebo (100 patients) for 6 months, beginning at least 1 week before ECV. Selection of conventional antiarrhythmic prophylaxis was left to local medical advice. The cardiac rhythm was assessed by both trans-telephonic monitoring and clinical visits. Primary end-point was the recurrence rate of AF. Sinus rhythm was restored, either spontaneously or after ECV, in 187 patients (91.7%); 95 patients (91.4%) on PUFAs and 92 patients (92.0%) on placebo (P=not significant). AF relapsed in 56 (58.9%) of the PUFAs patients and in 47 (51.1%) of the placebo patients (P=0.28). The mean time to AF recurrence was 83±8 days in the PUFAs group and 106±9 days in the placebo group (P=0.29). CONCLUSION: Our results do not support the hypothesis that, in patients undergoing ECV of chronic persistent AF, supplementation with PUFAs in addition to the usual antiarrhythmic treatment reduces recurrent AF.