Do fish oils prevent restenosis after coronary angioplasty?

Circulation

Nov 1994

DOI: 10.1161/01.CIR.90.5.2248

Citations:232

Influential Citations:4

Interventional (Human) Studies

Low RoB

Enhanced Details

Methods

Eight-center, randomized, double-blind, placebo-controlled trial. Participants: adults undergoing elective PTCA for native coronary vessels; 551 randomized (corn oil n=276, fish oil n=275); 447 evaluable at 6 months. Inclusion: native-vessel lesions causing ischemic symptoms or >50% stenosis by quantitative coronary angiography; Exclusion: questionable compliance, steroid/immunosuppressive therapy, aspirin intolerance, nonatherosclerotic heart disease, serious comorbidity with survival <2 years, stroke within 6 months, poorly controlled sustained hypertension, pregnancy, age >80, or <12 days between enrollment and scheduled PTCA.

Intervention

Ten 1.0-g capsules daily containing 80.6% ethyl esters of omega-3 fatty acids, providing 4.1 g EPA and 2.8 g DHA per day (about 8 g/d total omega-3). Capsules also contained 12 mg alpha-tocopherol and 28 mg gamma-tocopherol. Taken from 12–14 days before PTCA through 6 months after PTCA. Placebo capsules contained corn oil with equal vitamin E content.

Results

High-dose omega-3 fish oil did not reduce restenosis after PTCA. Restenosis: 46% in corn oil vs 52% in fish oil (P=0.37). No difference in major adverse events. No adverse effects attributed to the large daily omega-3 supplement. Authors conclude that 8 g/d omega-3 fatty acids for 6 months did not prevent restenosis after PTCA.

Limitations

447 of 551 randomized patients evaluable; per-patient analysis in multi-lesion PTCA; baseline differences in hypertension between groups; no adjustment for multiple subgroup analyses; limited power to detect small benefits; 95% CI for restenosis risk reduction with fish oil vs corn oil: −37% to +6%.

Abstract

BACKGROUND The omega-3 polyunsaturated fatty acids derived from fish oils have been shown to modulate many factors believed to affect the pathogenesis of atherosclerosis. Because certain features of restenosis following angioplasty mimic some of the early changes of atherogenesis, some researchers have suggested that fish oil might prevent restenosis following angioplasty. We report the effects of omega-3 fatty acids on the rate of restenosis following percutaneous intraluminal coronary angioplasty (PTCA). METHODS AND RESULTS From August 1989 through September 1992, 551 patients were randomized to start receiving a daily dietary supplement of ten 1.0-g capsules containing 80.6% ethyl esters of omega-3 fatty acids providing 4.1 g eicosapentaenoic acid (EPA) and 2.8 g docosahexaenoic acid (DHA) for 6 months or an equal amount of an ethyl ester of corn oil. Four hundred seventy subjects who were well matched for risk factors completed successful angioplasty of one or multiple lesions in native coronary vessels and constituted the study cohort, of whom 447 were evaluable at 6 months after PTCA. The criteria for restenosis were that the quantitative coronary angiography at 6 months show a > 30% increase in narrowing at the stenosis site or loss of at least half of the gain achieved at the time of PTCA and final restenosis with < 50% luminal diameter remaining. In 93% of the patients, the end point was determined by angiography and in all except 1% of these by quantitative coronary angiography. Compliance with the fish oil supplement was good as judged by incorporation of EPA and DHA in plasma and red blood cell phospholipids. The restenosis rate among analyzable patients was 46% for corn oil and 52% for fish oil (P = .37). The addition of 200 mg alpha-tocopherol for all subjects during the study had no effect on restenosis rates. CONCLUSIONS This was the largest of such trials to date, and a supplement of 8 g/d of omega-3 fatty acids failed to prevent the usual high rate of restenosis after PTCA. No adverse effects were attributable to this large daily supplement of omega-3 fatty acids. show less