Fish Oil in Haemodialysis Patients Cuts Cardiovascular Events 43%: 1,228-Person Placebo-Controlled Trial
In a double-blind trial of dialysis patients, the group taking high-dose omega-3 fatty acid supplements had fewer major cardiovascular events than the placebo group.

Cardiovascular disease is the leading cause of death in haemodialysis patients, but few preventive measures have been proven effective. The PISCES trial, led by the University Health Network in Toronto, Canada, and others, tested the effect of omega-3 polyunsaturated fatty acids (n-3 PUFAs) from fish oil in this patient group and published the results in NEJM.
Design
This was a double-blind, placebo-controlled trial at 26 sites in Canada and Australia in which 1,228 adults on maintenance haemodialysis were randomly assigned to a fish oil group (610) or a corn oil placebo group (618). The fish oil group took 4 g of omega-3 a day (EPA 1.6 g, DHA 0.8 g). The primary endpoint was major cardiovascular events, a composite of sudden cardiac death, myocardial infarction, peripheral vascular disease leading to amputation, stroke and others.
Over 3.5 years of follow-up, the rate of major cardiovascular events was 0.31 per 1,000 patient-days in the fish oil group and 0.61 in the placebo group, a hazard ratio of 0.57. Omega-3, whose possible cardiovascular benefit has been discussed in the general population, thus showed a clear difference even in dialysis patients, a group in which the evidence had been uncertain.
However, the results are limited to haemodialysis patients and cannot be applied as is to the general public or to people with other conditions. The dose used, 4 g a day, is also on the high side, so the results should not be interpreted as grounds for recommending any particular supplement.
- 1,228 adults on maintenance haemodialysis, fish oil 4 g/day vs corn oil placebo
- Major cardiovascular events over 3.5 years: 0.31 vs 0.61 per 1,000 patient-days, hazard ratio 0.57
- Results limited to dialysis patients and not applicable to the general public
Limitations This is a high-dose trial in haemodialysis patients and does not indicate the effect of taking supplements in the general population.
Original research
- Lok CE, et al. (PISCES Investigators) · University Health Network, Toronto. Fish-Oil Supplementation and Cardiovascular Events in Patients Receiving Hemodialysis. The New England Journal of Medicine. DOI: 10.1056/NEJMoa2513032
Copyright in the original research belongs to its publisher and authors.