Fatty acids and TxA2 generation, in the absence of platelet-COX-1 activity

Background and aimsOmega-3 fatty acids suppress Thromboxane A2 (TxA2) generation via mechanisms independent to that of aspirin therapy. We sought to evaluate whether baseline omega-3 fatty acid levels influence arachidonic acid proven platelet-cyclooxygenase-1 (COX-1) independent TxA2 generation (TxA2 generation despite adequate aspirin use).Methods and resultsSubjects with acute myocardial infarction, stable CVD or at high risk for CVD, on adequate aspirin therapy were included in this study. Adequate aspirin action was defined as complete inhibition of platelet-COX-1 activity as assessed by <10% change in light transmission aggregometry to ≥1 mmol/L arachidonic acid. TxA2 production was measured via liquid chromatography-tandem mass spectrometry for the stable TxA2 metabolite 11-dehydro-thromboxane B2 (UTxB2) in urine. The relationship between baseline fatty acids, demographics and UTxB2 were evaluated. Baseline omega-3 fatty acid levels were not associated with UTxB2 concentration. However, smoking was associated with UTxB2 in this study.ConclusionBaseline omega-3 fatty acid levels do not influence TxA2 generation in patients with or at high risk for CVD receiving adequate aspirin therapy. The association of smoking and TxA2 generation, in the absence of platelet COX-1 activity, among aspirin treated patients warrants further study.