Relationship between coronary plaque vulnerability and serum n-3/n-6 polyunsaturated fatty acid ratio

A low ratio of serum eicosapentaenoic acid to arachidonic acid (EPA/AA) has been associated with cardiovascular events. Higher-grade yellow color coronary plaques are associated with higher plaque vulnerability and higher thrombogenic potential. Therefore, the association between EPA/AA ratio and yellow color grade of coronary plaques was examined.

Consecutive patients (n=54) who underwent percutaneous coronary intervention were enrolled in this study. The serum EPA/AA ratio was examined on admission. All patients underwent an angioscopic examination of the culprit vessel to examine the color grade of yellow plaques (0, white; 1, slight yellow; 2, yellow; and 3, intense yellow) and the presence of thrombus. Excluding 16 patients with acute coronary syndrome (ACS), 38 patients with stable angina were divided into 2 groups according to their EPA/AA ratio: the low EPA/AA group (n=19, EPA/AA ratio <0.37 [median]) and the high EPA/AA group (n=19, EPA/AA ratio ≥0.37). The maximum color grade (2.5 ± 0.5 vs. 1.9 ± 0.9; P=0.01) of yellow plaques was significantly higher and the number of non-culprit yellow plaques with thrombus (1.7 ± 0.8 vs. 1.2 ± 1.1; P=0.06) tended to be higher in low EPA/AA than in high EPA/AA stable angina patients. Multivariate analysis revealed that the serum EPA level (odds ratio=0.98, 95% confidence interval=0.96-0.99, P=0.03) was associated with the presence of grade-3 yellow plaques.

A low serum EPA level and a low EPA/AA ratio was associated with high vulnerability of coronary plaques.