n-3 Polyunsaturated Fatty Acids in the Prevention of Atrial Fibrillation Recurrences After Electrical Cardioversion

Study Questions:

Do n-3 polyunsaturated fatty acids (PUFAs) prevent recurrences of atrial fibrillation (AF) after cardioversion?


One hundred ninety-nine patients (mean age 70 years, 90% with structural heart disease) with persistent AF were treated with amiodarone, 200 mg/day, and the maximally-tolerated dose of an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-receptor blocker (ARB). One month before cardioversion, the patients were randomly assigned to treatment with 1 g twice daily of PUFAs (n = 100) or a matching placebo (n = 99). Treatment was continued for 1 year. Serial electrocardiograms and Holter monitor recordings were performed during follow-up. The primary endpoint was sinus rhythm at 1 year after cardioversion.


Sinus rhythm was present at 1 year of follow-up significantly more often in the PUFA group (62%) than in the placebo group (36%). After adjustment for confounding variables such as left atrial size, the only variable independently associated with sinus rhythm at 1 year was treatment with PUFAs.


The authors concluded that when used in conjunction with amiodarone and an ACEI or ARB, PUFAs prevent recurrent AF after cardioversion.


These results seemingly are at odds with the results of a recent randomized study (Kowey PR, et al., JAMA 2010;304:2363-72), in which PUFAs were found to not prevent recurrences of paroxysmal or persistent AF. However, in that study, the patients did not have structural heart disease and were not treated with amiodarone. It is possible that PUFAs exert an antiarrhythmic effect only in the presence of structural remodeling and in conjunction with amiodarone.

Clinical Topics: Arrhythmias and Clinical EP, Dyslipidemia, EP Basic Science, Atrial Fibrillation/Supraventricular Arrhythmias, Lipid Metabolism, Nonstatins

Keywords: Heart Atria, Recurrence, Follow-Up Studies, Fatty Acids, Omega-3, Electric Countershock, Atrial Fibrillation, Electrocardiography

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