BACKGROUND Vascular healing response associated with adjunctive n-3 polyunsaturated fatty acid therapy therapy in patients receiving strong statin therapy remains unclear. The aim of this study was to evaluate the effect of polyunsaturated fatty acid therapy with eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in addition to strong statin therapy on coronary atherosclerotic plaques using optical coherence tomography. METHODS AND RESULTS This prospective multicenter randomized controlled trial included 130 patients with acute coronary syndrome treated with strong statins. They were assigned to either statin only (control group, n=42), statin+high-dose EPA (1800 mg/day) (EPA group, n=40), statin+EPA (930 mg/day)+DHA (750 mg/day) (EPA+DHA group, n=48). Optical coherence tomography was performed at baseline and at the 8-month follow-up. The target for optical coherence tomography analysis was a nonculprit lesion with a lipid plaque. Between baseline and the 8-month follow-up, fibrous cap thickness (FCT) significantly increased in all 3 groups. There were no significant differences in the percent change for minimum FCT between the EPA or EPA+DHA group and the control group. In patients with FCT <120 µm (median value), the percent change for minimum FCT was significantly higher in the EPA or EPA+DHA group compared with the control group. CONCLUSIONS EPA or EPA+DHA therapy in addition to strong statin therapy did not significantly increase FCT in nonculprit plaques compared with strong statin therapy alone, but significantly increased FCT in patients with thinner FCT. Registration URL: https://www.umin.ac.jp/ctr/; Unique identifier: UMIN 000012825.
Keywords: fatty acid; fibrous cap; optical coherence tomography.