The long-term effects of fish-oil supplementation on haemostatic parameters and bleeding episodes were investigated in patients undergoing coronary artery bypass surgery.

They were investigated before and 9 months after the operation. Following randomization postoperatively, 260 patients received 4 g fish-oil concentrate per day, whereas 251 patients comprised the control group. All patients received either aspirin (300 mg/day) or warfarin (international normalized ratio aimed at 2.5-4.2). Compliance was affirmed by determination of serum phospholipid fatty acids.

No excess of bleeding episodes could be attributed to the use of fish oil, given in addition to either aspirin or warfarin. The supplementation of fish oil did not affect the bleeding time or plasma levels of beta-thromboglobulin, whereas an increase in the platelet count after the operation was slightly less pronounced in the fish-oil group.

Apart from a small increase in PAI-1 antigen of borderline significance, no long-term effects by fish oil on parameters of coagulation and fibrinolysis were seen.