Long-Term Omega-3 Polyunsaturated Fatty Acid Supplementation Reduces the Recurrence of Persistent Atrial Fibrillation After Electrical Cardioversion

Study Questions:

Does fish oil prevent recurrent atrial fibrillation (AF) after cardioversion?


One hundred seventy-eight patients (mean age 62 years) with persistent AF were randomly assigned to an omega-3 group (6 g/day of fish oil for ≥1 month prior to cardioversion, n = 91) or to a control group (n = 87). Concurrent therapy with sotalol or amiodarone was permitted in both groups. In the omega-3 group, treatment with fish oil was continued for 1 year or until AF recurred. The patients were followed at regular intervals for 1 year post-cardioversion. The primary endpoint was recurrence of AF.


Forty-five percent of patients were treated with sotalol and 33% with amiodarone, with no differences in concurrent drug therapy between the two study arms. In the omega-3 group, patients received fish oil for a mean of 56 days before cardioversion. The 90-day AF recurrence rate after cardioversion was significantly lower in the omega-3 group (38.5%) than in the control group (77.5%), as was the 1-year AF recurrence rate (67% vs. 90%, respectively). The effect of fish oil on recurrent AF was independent of concurrent antiarrhythmic drug therapy.


The authors concluded that pretreatment with fish oil reduces the probability of recurrent AF after electrical cardioversion.


Prior studies of fish oil for AF prevention have had conflicting results, possibly because of variability between studies in dosage and duration of pretreatment. Long-term fish oil administration results in prolongation of atrial refractoriness and downregulation of profibrillatory cardiac connexins and proinflammatory cytokines. The results of this study suggest that ≥1 month of treatment with 6 g/day is sufficient for the antiarrhythmic effects of fish oil to become manifest.

Clinical Topics: Dyslipidemia, Prevention, Lipid Metabolism, Nonstatins, Diet

Keywords: Fish Oils, Dietary Supplements, Fatty Acids

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