n-3 Polyunsaturated fatty acids for the prevention of postoperative atrial fibrillation

BACKGROUND: n-3 Polyunsaturated fatty acids (n-3 PUFAs) have been proposed as prophylactic therapy in the prevention of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery. We conducted a meta-analysis of randomized controlled trials to better clarify this issue. METHODS: An electronic database search for randomized controlled trials on the effect of n-3 PUFAS on POAF was conducted, limited to English language publications until December 2010. For each study, data regarding the incidence of POAF were used to generate risk ratio (<1, favors n-3 PUFA; >1, favors placebo). Pooled summary effect estimate was calculated by means of a fixed or random effect according to heterogeneity. Meta-regression was used to investigate the effect of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) ratio and preoperative β-blockers on the effect of n-3 PUFA on POAF. RESULTS: Three publications were included in the analysis, enrolling a total of 431 patients. Overall incidence of POAF ranged from 24 to 54%. Pooling data, n-3 PUFA did not show a significant effect on the risk of POAF [risk ratio 0.89; 95% confidence interval (CI) 0.55-1.44; P=0.63]. However, meta-regression analysis showed a trend toward a benefit from n-3 PUFA supplementation when the EPA/DHA ratio was 1:2 (Q model=7.4; p model=0.02) and when preoperative β-blocker rate was lower (Q model=8.0; p model=0.01). CONCLUSION: In conclusion, the results of the present meta-analysis of randomized controlled trials suggest that preoperative n-3 PUFA therapy may not reduce POAF in patients undergoing cardiac surgery. However, several aspects may have influenced this negative result, which need to be investigated.