Fish oil supplementation reduces CV events in patients receiving hemodialysis

In the PISCES trial among patients undergoing maintenance hemodialysis, daily supplementation with fish-oil reduced the risk of serious cardiovascular events compared with placebo.

This summary is based on the publication of Lok CE, Farkouh M, Hemmelgarn BR, et al. - Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis. N Engl J Med. 2026 Jan 8;394(2):128-137. Epub 2025 Nov 7. doi: 10.1056/NEJMoa2513032.

Introduction and methods

Background

Cardiovascular disease is the leading cause of death among patients receiving maintenance hemodialysis [1], yet few preventive therapies have proven effective in this population [2]. Omega-3 (n−3) fatty acids may reduce the risk of cardiovascular events in the general population [3,4], but whether they have a benefit in patients receiving hemodialysis remains uncertain.

Aim of the study

The aim of the study was to evaluate the effect of oral fish-oil supplementation versus placebo on cardiovascular events in patients receiving maintenance haemodialysis.

Methods

PISCES (Protection against Incidences of Serious Cardiovascular Events Study) was a multicenter, double-blind, randomized, placebo-controlled trial conducted in Canada and Australia, in which 1228 patients with end-stage kidney disease on maintenance hemodialysis were randomized 1:1 to fish-oil supplementation (4 g/day n−3 polyunsaturated fatty acids [EPA 1.6 g and DHA 0.8 g]) or corn-oil placebo. Patients were followed for up to 3.5 years.

Outcomes

The primary outcome was a composite of all serious cardiovascular events including cardiovascular death (sudden and nonsudden cardiac death), fatal and nonfatal MI, peripheral vascular disease leading to amputation, and fatal and nonfatal stroke. Secondary endpoints included extension of the primary endpoint to include noncardiac causes of death, individual components of the primary endpoint, and a first cardiovascular event or death from any cause.

Main results

Primary outcomes

• The rate of the primary composite outcome was lower in the fish-oil group compared with the placebo group (0.31 vs. 0.61 events per 1,000 patient-days; HR 0.57; 95%CI: 0.47–0.70; P<0.001).
• The primary outcome was reduced to a similar extent in patient with and without a previous cardiovascular event (HR: 0.50 for a previous cardiovascular event; 95%CI: 0.37–0.67; HR: 0.55 for no previous cardiovascular event; 95%CI: 0.40–0.76).

Secondary outcomes

• The extended primary outcome that included noncardiac causes of death was reduced in the fish-oil group compared with the placebo group (HR: 0.77; 95%CI: 0.65–0.90).
• All individual components of the primary outcome were lower in the fish-oil group compared with the placebo group.
• The risk of a first cardiovascular event or death from any cause was also lower in the fish-oil group compared with the placebo group (HR 0.73; 95%CI: 0.61–0.87).

Safety

• The rate of serious bleeding was 4.8% in the fish-oil group and 7.6% in the placebo group.
• The rates of other serious adverse events were similar between the groups.

Conclusion

In the PISCES trial among patients receiving maintenance dialysis, supplementation with fish-oil reduced the risk of serious cardiovascular events compared with placebo. The authors highlighted that “many of the trial participants were not receiving therapy that would be considered sufficient to reduce cardiovascular risk in general populations at increased risk, and the results may not be generalizable to patients who are not undergoing dialysis.”

Find this article online at N Engl J Med.

References

1. See E, Ethier I, Cho Y, et al. Dialysis outcomes across countries and regions: a global perspective from the International Society of Nephrology global kidney health atlas study. Kidney Int Rep 2024;9:2410-9.
2. Zhang Z, Wang Y. Management of cardiovascular diseases in chronic hemodialysis patients. Rev Cardiovasc Med 2023; 24:185.
3. Dinu M, Sofi F, Lotti S, et al. Effects of omega-3 fatty acids on coronary revascularization and cardiovascular events: a meta-analysis. Eur J Prev Cardiol 2024;31:1863-75.
4. Dong S, Wang Y, Bian J, et al. The effect of omega-3 polyunsaturated fatty acid (PUFA) prescription preparations on the prevention of clinical cardiovascular disease: a meta-analysis of RCTs. Nutr J 2024; 23:157.