Fish oil reduces cardiovascular events in hemodialysis
Daily fish-oil capsules lowered serious cardiovascular events in adults receiving long-term hemodialysis.
*Double-blind randomized placebo-controlled trial; Level 1b (OCEBM).

Citation

Lok CE, Farkouh M, Hemmelgarn BR, et al.; PISCES Investigators. Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis. N Engl J Med. 2026;394:128-137. doi:10.1056/NEJMoa2513032.

Background

People receiving hemodialysis have very high cardiovascular risk, and few preventive treatments clearly help. Fish-oil (omega-3) supplements may protect the heart, but benefits in hemodialysis were uncertain.

Patients

1228 adults (≥18 years) receiving maintenance hemodialysis at 26 sites in Canada and Australia.

Intervention

Fish oil 4 g daily (total 1.6 g eicosapentaenoic acid + 0.8 g docosahexaenoic acid).

Control

Corn-oil placebo capsules.

Outcome

(Primary) Composite of serious cardiovascular events: cardiac death, heart attack, stroke, or leg blood-vessel disease leading to amputation (recurrent events counted). Secondary outcomes included adding non-cardiac death and first cardiovascular event or death.

Follow-up Period

Up to 3.5 years.

Results

Outcome Fish oil Placebo Significant effect
Serious cardiovascular events (primary) 0.31 per 1000 patient-days 0.61 per 1000 patient-days Hazard ratio 0.57 (95% CI, 0.47–0.70)
Serious cardiovascular events + non-cardiac death 0.52 per 1000 patient-days 0.76 per 1000 patient-days Hazard ratio 0.77 (95% CI, 0.65–0.90)
First cardiovascular event or death (any cause) 0.45 per 1000 patient-days 0.60 per 1000 patient-days Hazard ratio 0.73 (95% CI, 0.61–0.87)
At least one serious cardiovascular event 20.8% 33.7% Number needed to treat: 8 (over 3.5 years)
Analyses followed an intention-to-treat approach among participants who took at least one dose.

Limitations

Participants who switched to peritoneal dialysis or received a transplant were censored, so effects after switching are unknown. Over-the-counter fish oil use outside the trial could not be fully excluded. Bleeding events were not formally adjudicated. Blood omega-3 levels were checked in only a subset. Use of other heart-protective medicines (for example, cholesterol-lowering drugs) was not universal, which may affect generalizability.

Funding

Heart and Stroke Foundation of Canada; public agencies; in-kind capsules from DSM.

Clinical Application

For stable adults on hemodialysis, consider daily fish-oil supplementation to reduce serious cardiovascular events, while continuing standard risk management and monitoring tolerance.