Clinical Significance of Serum Omega-3 Fatty Acids on Endothelial Function in Patients with Coronary Artery Disease Under Statin Therapy

Vascular endothelial function plays an important role in the pathogenesis of atherosclerosis. The reduction in low-density lipoprotein cholesterol (LDL-C) is a key therapy for preventing coronary artery disease (CAD), but the role of omega-3 fatty acids as residual risk factors of CAD remains controversial. We studied the correlation between serum omega-3 fatty acid levels and endothelial function in patients with CAD receiving statin therapy and examined the effect of eicosapentaenoic acid (EPA) therapy on endothelial function. Methods: A total of 150 consecutive patients with CAD receiving statin therapy (LDL-C levels < 100 mg/dL) were enrolled. Serum omega-3 fatty acid levels were measured, and endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery. Subsequently, 65 patients with impaired FMD (<6%) and low EPA/arachidonic acid (AA) (<0.3) were administered EPA, and FMD was reassessed after 3 months. Results: A multivariate linear regression analysis demonstrated that serum docosahexaenoic acid (DHA) and EPA plus DHA levels were independent determinants of %FMD (β = 0.214 and 0.163, p < 0.05, respectively). The EPA therapy significantly improved %FMD (from 3.7 ± 1.0% to 4.1 ± 1.0%, p < 0.05) in patients with low EPA/AA, and especially in patients with low EPA/AA and high triglyceride levels (from 3.4 ± 1.0% to 4.0 ± 1.1%, p < 0.01). Conclusions: Serum omega-3 fatty acid levels were associated with endothelial dysfunction in patients with CAD receiving statin therapy. EPA therapy improves endothelial function in patients with low EPA/AA, especially those with low EPA/AA and high triglycerides.