Add-on Antiplatelet Effects of Eicosapentaenoic Acid With Tailored Dose Setting in Patients on Dual Antiplatelet Therapy.

The aim of this study was to investigate the antiplatelet effects of eicosapentaenoic acid (EPA) at a sufficient dose following coronary stent implantation. Thirty-one patients on dual antiplatelet therapy with aspirin and clopidogrel were treated with highly purified EPA-E (Epadel®) for 12 weeks. Based on our previous study, patients with a high baseline EPA/arachidonic acid (AA) ratio (≥ 0.37; n = 11) were given a standard dose (1800 mg daily) of EPA-E, whereas those with a low EPA/AA ratio (< 0.37; n = 20) were given a high dose (2700 mg daily) to reach the target value of > 0.92. Platelet function was then evaluated with agonist-induced aggregation using light transmittance aggregometry and VerifyNow®. After EPA-E treatment, the EPA/AA ratio significantly increased from 0.28 to 1.31 (P < 0.001). Collagen (1, 2, and 4 μg/mL)-induced maximal platelet aggregation (MPA) was significantly suppressed after EPA-E administration (from 28.0 to 24.0, P = 0.033; from 44.0 to 40.0, P = 0.016; from 60.0 to 56.0, P = 0.010; respectively). However, there were no changes in MPA induced by adenosine diphosphate and AA and in P2Y12 reaction units (PRU) and aspirin reaction units. After EPA-E treatment, PRU was significantly suppressed in 8 patients showing high on-treatment platelet reactivity (HTPR) (baseline 305; 266-321 versus on-treatment 256; 233-261, P = 0.012), but not in those without HTPR (201; 156-220 versus 183; 159-233, P = 0.212). In conclusion, EPA treatment at a sufficient dose suppressed platelet aggregation and showed possible add-on effects in patients with clopidogrel hyporesponsiveness.