Effects of polyunsaturated omega-3 fatty acids on responsiveness to dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: the OMEGA-PCI (OMEGA-3 fatty acids after pci to modify responsiveness to dual antiplatelet therapy) study.

OBJECTIVES The purpose of this study was to investigate whether omega-3 polyunsaturated fatty acids (PUFAs) are able to modify platelet responsiveness to dual antiplatelet therapy in stable coronary artery disease patients undergoing percutaneous coronary intervention (PCI). BACKGROUND Although previous studies have suggested antiplatelet properties of omega-3 polyunsaturated fatty acids, it is unknown whether they can enhance platelet inhibition on standard aspirin and clopidogrel treatment. METHODS The OMEGA-PCI (OMEGA-3 Fatty Acids After PCI to Modify Responsiveness to Dual Antiplatelet Therapy) study was an investigator-initiated, prospective, single-center, double-blind, placebo-controlled, randomized study. Patients receiving standard dual antiplatelet therapy (aspirin 75 mg/day and clopidogrel 600 mg loading dose followed by 75 mg/day) were randomly assigned to receive the addition of 1 g of omega-3 ethyl esters (n = 33) or placebo (n = 30) for 1 month. Platelet function was measured serially by light transmission aggregometry (adenosine diphosphate and arachidonic acid [AA] were used as agonists) and assessment of the phosphorylation status of the vasodilator-stimulated phosphoprotein at baseline, 12 h, 3 to 5 days, and 30 days after randomization. RESULTS The P2Y(12) reactivity index was significantly lower, by 22.2%, after 1 month of treatment with omega-3 polyunsaturated fatty acids compared with placebo when used in addition to dual antiplatelet therapy (p = 0.020). Maximal platelet aggregation induced by 5 and 20 micromol/l adenosine diphosphate was lower by 13.3% (p = 0.026) and 9.8% (p = 0.029), respectively, after 1 month of treatment with omega-3 polyunsaturated fatty acids compared with placebo. Platelet aggregation after AA stimulation was low and did not change significantly throughout the study. There were no cases of aspirin resistance during follow-up that was suggestive of good compliance with the medication. CONCLUSIONS The addition of omega-3 ethyl esters to the combination of aspirin and clopidogrel significantly potentiates platelet response to clopidogrel after percutaneous coronary intervention.