Do fish oils prevent restenosis after coronary angioplasty?

Multicenter randomized trial in adults scheduled for elective percutaneous transluminal coronary angioplasty of native coronary arteries. Eligible patients had ischemic symptoms or >50% stenosis in native vessels and no prior angioplasty; eight collaborating centers enrolled participants between August 1989 and September 1992.

Fish oil was given orally as ten 1-g gelatin capsules daily for 6 months, providing 8 g/day of omega-3 fatty acids in ethyl ester form, including EPA 4.1 g/day and DHA 2.8 g/day. The active regimen was compared with an ethyl ester corn oil placebo; all participants also received standard care and a Step-One American Heart Association diet.

High-dose fish oil did not reduce restenosis after PTCA. At 6 months, restenosis was 52% with fish oil versus 46% with corn oil placebo among analyzable patients, with no significant difference (P=.37); the reported 95% confidence interval for the decrease in risk was -37% to +6%. Adverse events were similar between groups, and no fish-oil-related safety signal was identified. The authors concluded that fish oil supplementation did not prevent restenosis after PTCA.

The trial had only 6 months of follow-up and a moderate number of evaluable patients, with some dropouts and unevaluable cases. Dietary compliance varied, vitamin E was added during the study for all subjects, and the population was limited to elective PTCA patients at eight centers, which may reduce generalizability.