Figure. Randomized Controlled Trials of Peri-Operative Fish Oil Supplementation to Prevent Post-Operative Atrial Fibrillation.

Studies were pooled using inverse-variance weighted meta-analysis with fixed effects. Although the overall pooled result was of borderline statistical significance, substantial heterogeneity was evident (I²=52%, Q statistic=14.5), which was largely explained by whether trials were open label (top 2 studies) versus placebo-controlled (bottom 6 studies). The open-label studies suggested a benefit, but the double-blind, placebo-controlled trials confirmed no significant effect of fish oil on post-operative atrial fibrillation (OR=0.92, 95% CI=0.78–1.10), with little heterogeneity between studies (I²=16%, Q statistic=5.93). Sensitivity analyses using random effects meta-analysis showed similar findings for the overall pooled results (OR=0.76, 95% CI=0.57–1.03; I²=52%, Q statistic=14.5, P-heterogeneity = 0.04), results restricted to open-label trials (OR=0.40, 95% CI=0.23–0.68; I²=0%, Q statistic=0.13, P-heterogeneity=0.72), and results restricted to placebo-controlled trials (OR=0.91, 95% CI=0.73–1.13; I²=16%, Q statistic=5.93, P-heterogeneity=0.31).