Kumar S et al. – Omega–3 polyunsaturated fatty acid supplementation commenced >1 month prior to electrical cardioversion and continued thereafter reduces the recurrence of persistent atrial fibrillation (AF). Randomized controlled trials on long–term fish oil supplementation are needed to confirm these findings.

• This was an open–label, randomized study of 178 patients with persistent AF >1–month duration.
• Participants were assigned to control group (n = 87) or omega–3 group (6 g/d fish oil; n = 91) and underwent cardioversion 1 month later.
• Concurrent antiarrhythmic use of sotalol or amiodarone was permitted.
• Fish oil was continued till return of persistent AF or a maximum of 1 year.
• Intention–to–treat analysis was performed for the primary end point defined as the recurrence of persistent AF.

• Mean duration of fish oil intake was 56 days precardioversion and a total of 242 days in follow–up.
• Eicosapentaenoic acid and docosahexaenoic acid, the active components of fish oils, were 1.8–fold and 2.1–fold higher, respectively, in the omega–3 group compared with controls at the time of cardioversion (P <.001).
• At 90 days, 38.5% of the patients receiving omega–3 fatty acid supplement had AF recurrence compared with 77.5% of the controls (hazard ratio [omega–3 vs control] 0.38; 95% confidence interval 0.27–0.56; P <.001).
• Omega–3 intake was associated with a significant reduction in AF recurrence with or without concurrent antiarrhythmic drugs.