Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

BACKGROUND: There is a potential concern about increased bleeding risk in patients receiving omega-3 polyunsaturated fatty acids (PUFAs). The aims of this study-level meta-analysis were to determine the risk of bleeding and to assess whether this relationship is linked to the received dose of omega-3 PUFAs or the background use of antiplatelet treatment. METHODS AND RESULTS: Electronic databases were searched through May 2023 to identify randomized clinical trials of patients receiving omega-3 PUFAs. Overall bleeding events, including fatal and central nervous system events, were identified and compared with those of a control group. A total of 120 643 patients from 11 randomized clinical trials were included. There was no difference in the pooled meta-analytic events of bleeding among patients receiving omega-3 PUFAs and those in the control group (rate ratio [RR], 1.09 [95% CI, 0.91-1.31]; P=0.34). Likewise, the incidence of hemorrhagic stroke, intracranial bleeding, and gastrointestinal bleeding were similar. A prespecified analysis was performed in patients receiving high-dose purified eicosapentaenoic acid (EPA), which demonstrated a 50% increase in the relative risk of bleeding but only a modest increase in the absolute risk of bleeding (0.6%) when compared with placebo. Bleeding risk was associated with the dose of EPA (risk difference, 0.24 [95% CI, 0.05-0.43]; P=0.02) but not the background use of antiplatelet therapy (risk difference, -0.01 [95% CI, -0.02 to 0]; P=0.056). CONCLUSIONS: Omega-3 PUFAs were not associated with increased bleeding risk. Patients receiving high-dose purified EPA may incur additional bleeding risk, although its clinical significance is very modest.