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.
