N-3 polyunsaturated fatty acids administration does not reduce the recurrence rates of atrial fibrillation and inflammation after electrical cardioversion: a prospective randomized study

Objective: The purpose of the present prospective randomized study was to evaluate the effects of n-3 polyunsaturated fatty acids on recurrence rates of atrial fibrillation (AF) and inflammation after electrical cardioversion. Methods: Calculation of the number of patients needed was based on the assumption of 20% and 65% chance of maintaining sinus rhythm with amiodarone and with polyunsaturated fatty acids, respectively. To observe a significant difference with an alpha level of 0.05 and a power of 0.80 it was necessary to include 22 patients in each group. A total of 47 patients were randomized to amiodarone (n=24) and amiodarone plus n-3 polyunsaturated fatty acids (n=23) groups before scheduled electrical cardioversion. The end-point was the recurrence of AF during 12-month follow-up. Effect of n-3 polyunsaturated fatty acids on inflammation was evaluated with high sensitivity C-reactive protein level measurements. Statistical analysis was performed using unpaired Student’ t, Mann Whitney U and Chi-square tests. We analyzed the recurrence of AF using the Cox proportional hazards regression model to control for potentially confounding factors. Results: Nine patients in the amiodarone group (37.5%), and 9 patients in the amiodarone plus n-3 polyunsaturated fatty acids group (39.1%) had recurrence of AF during follow-up (p=1). With the Cox proportional model, risk factors for the recurrence of AF were previous electrical cardioversion (HR 10.33, 95% CI 1.74 to 61.10, p=0.01) and high sensitivity C-reactive protein levels (HR 1.07, 95% CI 1.02 to 1.38, p=0.007). High sensitivity C-reactive protein levels at baseline, at day 15 and during AF recurrence were similar between two groups (p 0.05 for all). Conclusion: N-3 polyunsaturated fatty acids administration does not reduce the recurrence rates of atrial fibrillation and inflammation.