The study, known as the PISCES trial, followed 1,228 participants receiving dialysis at 26 sites across Australia and Canada. The findings were unveiled at the American Society of Nephrology Kidney Week 2025 and released at the same time in The New England Journal of Medicine.

Fewer Heart Attacks, Strokes, and Cardiac Deaths

Participants who took four grams of fish oil each day showed striking improvements. The supplement contained the natural omega-3 fatty acids EPA and DHA. Compared with those given a placebo, these patients experienced a 43 percent reduction in serious cardiovascular events. The outcomes measured included heart attacks, strokes, cardiac-related deaths, and vascular related amputations.

Adjunct Professor Kevan Polkinghorne, a nephrologist at Monash Health and adjunct in the School of Clinical Sciences, led the Australian portion of the trial.

“Patients on dialysis have extremely high cardiovascular risk, and very few therapies have been shown to reduce that risk,” Professor Polkinghorne said. “In a field where many trials have been negative, this is a significant finding.

“Dialysis patients typically have much lower levels of EPA and DHA than the general population. This may help explain the magnitude of benefit observed in this group.”

Findings Apply Only to Dialysis Patients

Professor Polkinghorne emphasized that the results are specific to people receiving hemodialysis for kidney failure. He cautioned that the findings should not be extended to healthy individuals or other patient populations.

The Australian arm of the trial was funded by the National Health and Medical Research Council (NHMRC). Overall trial coordination was managed by the Australasian Kidney Trials Network (AKTN). About 200 Australian patients took part in the study, including 44 who were treated at Monash Health.

International leadership of the PISCES trial came from Professor Charmaine Lok and her colleagues at the University Health Network in Toronto and the University of Calgary.