Use of fish oil to prevent coronary angioplasty restenosis

OBJECTIVE: To review the literature investigating the use of fish oil in preventing restenosis postangioplasty (RPA). DATA SOURCES: An Index Medicus and bibliographic search of the English-language literature pertaining to the use of fish oil in preventing RPA. The key terms used were fish oil, angioplasty, and eicosapentaenoic acid. STUDY SELECTION AND DATA EXTRACTION: The results of all trials, including abstracts, that were obtained are reviewed and critiqued. DATA SYNTHESIS: Restenosis of a coronary vessel at the site of angioplasty occurs 30-40 percent of the time. Because fish oil has been theorized to prevent atherosclerosis and because atherosclerotic-like processes are theorized to be involved in RPA restenosis, fish oil has been studied to determine whether it can prevent RPA. Results of such trials have been mixed. Some have observed a reduction in the number of patients with angiographic or clinical evidence of restenosis. Two trials have failed to observe such an effect. Reasons for the differences are unknown. Possible explanations include differences in study design, endpoint parameters, definition of restenosis, and dosing methods of the fish oil. Bleeding was not of significant concern in any of the trials, even when fish oil was combined with antiplatelet therapy. CONCLUSIONS: Fish oil may be considered for use in patients to prevent RPA. It probably should be continued for only six months following the procedure. Current data suggest that at least 3 g/d of eicosapentaenoic acid and 1 g/d of docosahexaenoic acid should be used. If possible, therapy should be started as soon as it is known that angioplasty will be performed or at least as soon as possible following the procedure. Many patients may not be able to tolerate fish oil because of its gastrointestinal effects.