Thrombin generation induced by tissue factor plus ADP in human platelet rich plasma: A potential new measurement to assess the effect of the concomitant use of an oral factor Xa inhibitor edoxaban and P2Y12 receptor antagonists

Introduction: Patients with atrial fibrillation undergoing percutaneous coronary intervention may require combination therapy with anticoagulants and antiplatelet agents. The objectives of this study were to establish an assay which can evaluate the effects of both anticoagulants and P2Y(12) receptor antagonists and determine the effects of edoxaban, a direct factor Xa inhibitor, and P2Y12 receptor antagonists (clopidogrel and ticagrelor) alone and when combined. Material and methods: Human platelet-rich plasma (PRP) from healthy subjects was stimulated with adenosine diphosphate (ADP) plus tissue factor. Thrombin generation was measured by means of calibrated automated thrombography. Results: Combination of 10 mu M ADP and lowconcentration (0.25 pM) tissue factor induced reproducible thrombin generation in human PRP. Edoxaban (40 and 80 ng/mL), active metabolite of clopidogrel (AM-clopidogrel, 10 and 20 mu g/mL), and ticagrelor (3 mu g/mL) alone inhibited ADP plus tissue factor-induced thrombin generation. Edoxaban suppressed all 5 parameters (lag time, peak, time to peak, endogenous thrombin potential, and maximum rate), whereas AM-clopidogrel and ticagrelor inhibited 4 and 3 parameters, respectively. Concomitant treatment with edoxaban and AM-clopidogrel or ticagrelor produced an additive inhibition of thrombin generation compared to the single treatments. Conclusions: The thrombin generation assay induced by ADP plus tissue factor can detect the activities of both edoxaban and P2Y12 receptor antagonists. Combination of edoxaban and a P2Y12 receptor antagonist shows additive inhibition. These results suggest that ADP plus tissue factor-induced thrombin generation may be a useful measurement to assess the combination effects of anticoagulants and P2Y12 receptor antagonists in a single assay. (C) 2015 Elsevier Ltd. All rights reserved.