Overview: A potential breakthrough for dialysis patients
A new study presented at Kidney Week 2025 and published simultaneously in The New England Journal of Medicine spotlighted a daily fish oil supplement as a potential way to reduce serious heart risks in people undergoing dialysis. The trial, known as PISCES, followed 1,228 participants across 26 sites in Australia and Canada and found a meaningful reduction in cardiovascular events among those taking the supplement compared with standard care. For millions living with kidney failure who rely on dialysis, this finding offers a possible adjunct to existing treatments aimed at protecting heart health.
What the PISCES trial found
The central finding of PISCES is that regular fish oil intake was associated with a lower risk of major adverse cardiovascular events in the dialysis population. While the study did not declare a single universal threshold of benefit for every patient, the overall trend pointed to a clinically important improvement in heart-related outcomes. Researchers emphasized that the benefit appeared across diverse patient subgroups, suggesting broad relevance for dialysis patients who face heightened cardiovascular risk.
Why this matters for dialysis patients
Cardiovascular disease is the leading cause of death in people on dialysis. Traditional risk factors—hypertension, dyslipidemia, inflammation, and fluid management—are often complicated by kidney failure. The prospect that a simple, daily supplement could modestly lower the likelihood of heart attacks, heart failure hospitalization, or sudden cardiac death is notable. If confirmed in further research and integrated into clinical practice, fish oil could become an accessible addition to the multifaceted care dialysis patients already receive.
How the study was conducted
PISCES enrolled 1,228 participants across 26 sites in Australia and Canada, randomizing them to receive either a daily fish oil supplement or a placebo, alongside standard dialysis care. The trial followed participants for a defined period, tracking cardiovascular events, hospitalizations, and safety outcomes. The researchers conducted rigorous analyses to account for variables such as age, sex, dialysis modality, and preexisting cardiovascular disease. By comparing outcomes between groups, the study aimed to isolate the potential cardiovascular benefits attributable to fish oil supplementation.
Interpretation, limitations, and next steps
While the results are promising, experts caution that fish oil is not a replacement for established heart-protection strategies in dialysis care. The interpretation of the data should consider potential limitations, including the regional scope of the trial and adherence patterns. Clinicians will want to weigh possible interactions with other medications, bleeding risk in some patients, and individual tolerance to omega-3 supplements. Additional studies in broader populations and longer follow-up could help define which patients stand to gain the most and how best to integrate fish oil into personalized dialysis plans.
Practical takeaways for patients and clinicians
- Discuss with a nephrologist or cardiologist before starting any new supplement to ensure it fits an individual risk profile.
- Consider the potential cardiovascular benefits of omega-3 fatty acids as part of a comprehensive dialysis care plan, not as a stand-alone solution.
- Monitor for safety concerns, including interactions with anticoagulants or bleeding risks, and report any adverse effects promptly.
- Stay updated on follow-up trials that confirm, refine, or extend these findings to other populations and settings.
Bottom line
The PISCES trial adds to a growing body of evidence suggesting that accessible interventions like daily fish oil could support heart health for people undergoing dialysis. While it does not replace recommended cardiovascular risk-reduction strategies, it points toward a potentially valuable addition to end-stage kidney disease care. As nephrology researchers continue to explore how best to protect the hearts of dialysis patients, patients and clinicians can look to this study as a meaningful milestone in the ongoing effort to reduce cardiovascular risk in this high-risk group.
