Effect of Fish Oil Supplementation on Graft Patency and Cardiovascular Events Among Patients With New Synthetic Arteriovenous Hemodialysis Grafts: A Randomized Controlled Trial

Study Questions:

What is the effect of fish oil on synthetic hemodialysis graft patency and cardiovascular events?


The FISH (Fish Oil Inhibition of Stenosis in Hemodialysis Grafts) study was a randomized, double-blind, controlled clinical trial conducted at 15 North American dialysis centers from November 2003 through December 2010, enrolling 201 adults with stage 5 chronic kidney disease (50% women, 63% white, 53% with diabetes), with follow-up for 12 months after graft creation. Participants were randomly allocated to receive fish oil capsules (four 1-g capsules/day) or matching placebo on day 7 after graft creation. The main outcome measure was the proportion of participants experiencing graft thrombosis or radiological or surgical intervention during 12-month follow-up.


The risk of the primary outcome did not differ between fish oil and placebo recipients (48/99 [48%] vs. 60/97 [62%], respectively; relative risk, 0.78; 95% confidence interval [CI], 0.60-1.03; p = 0.06). However, the rate of graft failure was lower in the fish oil group (3.43 vs. 5.95 per 1,000 access-days; incidence rate ratio [IRR], 0.58; 95% CI, 0.44-0.75; p < 0.001). In the fish oil group, there were one half as many thromboses (1.71 vs. 3.41 per 1,000 access-days; IRR, 0.50; 95% CI, 0.35-0.72; p < 0.001); fewer corrective interventions (2.89 vs. 4.92 per 1,000 access-days; IRR, 0.59; 95% CI, 0.44-0.78; p < 0.001); improved cardiovascular event-free survival (hazard ratio, 0.43; 95% CI, 0.19-0.96; p = 0.04); and lower mean systolic blood pressure (−3.61 vs. 4.49 mm Hg; difference, −8.10; 95% CI, −15.4 to −0.85; p = 0.01).


The authors concluded that daily fish oil ingestion did not decrease the proportion of grafts with loss of native patency within 12 months.


This study showed that graft thrombosis or a radiological or surgical intervention to maintain arteriovenous graft patency did not significantly differ between fish oil and placebo recipients. However, fish oil recipients had a prolonged time without thrombosis, one half the thrombosis rate, and a clinically meaningful reduction in frequency of radiological and surgical interventions. Important other findings include improved cardiovascular event-free survival and rate, as well as improved blood pressure and a reduction in use of antihypertensive medications in the fish oil group. These potential benefits on cardiovascular events require validation and confirmation in future prospective studies.

Clinical Topics: Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Prevention, Lipid Metabolism, Nonstatins, Diet

Keywords: Transplants, Fish Oils, Dietary Supplements, Capsules, Vascular Surgical Procedures

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