Prior research provides unclear results on the benefits of omega-3 fatty acids for the prevention of cardiovascular outcomes in patients with high cardiovascular risk. To determine the association of plasma levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with cardiovascular outcomes, researchers randomized patients at high cardiovascular risk with elevated triglyceride levels and low HDL cholesterol levels to 4 g daily of omega-3 carboxylic acid (CA) or corn oil placebo. The median plasma EPA level for the omega-3 griyo was 89 µg/mL, with the top tertile achieving levels of 151 µg/mL (a 443% increase). The median level of DHA was 91 µg/mL, rising to 118 g/mL (a 68% increase) in the top tertile. No differences were observed in the composite endpoint of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina requiring hospitalization. Event rates were 11.4% and 11.0% for those in the top tertile of achieved DHA levels and the corn oil group, respectively. “These findings suggest that supplementation of omega-3 fatty acids in high-risk cardiovascular patients is neutral even at the highest achieved levels,” the presenting author said. “And, in the context of increased risk of atrial fibrillation in omega-3 trials, they cast uncertainty over whether there is net benefit or harm with any omega-3 preparation.”