Low eicosapentaenoic acid to arachidonic acid ratio is associated with thin-cap fibroatheroma determined by optical coherence tomography.

Background: A low eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is known to be associated with cardiovascular events. However, the relationship between the EPA/AA ratio and coronary plaque vulnerability assessed by optical coherence tomography (OCT) has not been examined thoroughly. This study examined the relationship between the EPA/AA ratio and coronary plaque vulnerability assessed by OCT in patients with acute coronary syndrome (ACS).

Methods: We evaluated 59 ACS patients who had undergone percutaneous coronary intervention using OCT. We divided them into 2 groups according to OCT findings-those with and without thin-cap fibroatheroma (TCFA)-and compared the EPA/AA ratio between the groups.

Results: We identified 32 and 27 patients with and without TCFA, respectively. The EPA/AA ratio was significantly lower in patients with TCFA than in those without TCFA [0.35, interquartile range (0.21-0.44) vs. 0.54, interquartile range (0.42-0.70); p<0.001]. In multivariate logistic regression analysis, the EPA/AA ratio was an independent predictor of TCFA (odds ratio, 0.09; 95% confidence interval, 0.007-0.99; p=0.049). The EPA/AA ratio and fibrous cap thickness showed a significant positive correlation (Spearman ρ=0.46; p<0.001). Furthermore, receiver operating characteristic curve analysis showed that an EPA/AA ratio<0.46 could predict TCFA (81.3%, sensitivity; 74.1%, specificity).

Conclusions: A low serum EPA/AA ratio is significantly associated with coronary plaque vulnerability assessed by OCT in ACS patients.