Clinical Question: Does daily supplementation with omega-3 polyunsaturated fatty acids reduce cardiovascular events in patients on maintenance hemodialysis?
Background: Cardiovascular disease is the leading cause of death in hemodialysis patients. Established atherosclerotic therapies, such as statins, offer limited benefit in dialysis-dependent patients. Prior small randomized controlled trials and meta-analyses suggested a possible cardiovascular benefit of omega-3 supplementation, but the data were inconclusive.
Study Design: Multicenter, double-blind, randomized, placebo-controlled trial (the PISCES trial)
Setting: 26 hemodialysis centers in Canada and Australia
Synopsis: A total of 1,228 adults on maintenance hemodialysis were randomized to daily fish oil (4 g of omega-3 polyunsaturated fatty acids: 1.6 g eicosapentaenoic acid and 0.8 g docosahexaenoic acid; n=610) or corn-oil placebo (n=618). Over 3.5 years of follow-up, the primary composite endpoint of all serious cardiovascular events (cardiac death, myocardial infarction (MI), stroke, peripheral vascular disease leading to amputation) occurred at a significantly lower rate in the fish-oil group (0.31 versus 0.61 per 1,000 patient-days; HR, 0.57; CI, 0.47 to 0.70). Benefits were consistent across secondary endpoints: cardiac death (HR, 0.55), MI (HR, 0.56), stroke (HR, 0.37), and first cardiovascular event or death from any cause (HR, 0.73). Adherence and adverse events were similar between groups. Limitations of the study include that less than 60% of participants were on statins, this study only included patients receiving maintenance hemodialysis, and the corn-oil placebo could theoretically have had biological effects. These findings provide randomized evidence for the cardiovascular benefit of fish oil supplementation in hemodialysis patients.
Bottom Line: In hemodialysis patients, daily fish-oil supplementation with 1.6 g eicosapentaenoic acid and 0.8 g docosahexaenoic acid was shown to reduce serious cardiovascular events by 43%, representing a potentially important and accessible intervention for a population with few proven cardiovascular therapies.
Citation: Lok CE, et al. Fish-oil supplementation and cardiovascular events in patients receiving hemodialysis. N Engl J Med. 2026;394(2):128-37. doi:10.1056/NEJMoa2513032.
Dr. Fink
Dr. Fink is an academic hospitalist in the division of hospital medicine and associate program director of the internal medicine residency program at MedStar Washington Hospital Center and an assistant professor of medicine at Georgetown University School of Medicine, both in Washington, D.C.