Antiplatelet Effect of Single Antiplatelet Therapy With Prasugrel and Oral Anticoagulation After Stent Implantation in a Rabbit Arteriovenous Shunt Model

Background: Antiplatelet therapy following stent implantation in patients requiring oral anticoagulation (OAC) is controversial because triple therapy (i.e., dual antiplatelet therapy [DAPT] with OAC) is associated with a high risk of bleeding. Methods and Results: In this study, 21 rabbits were divided into 5 groups: prasugrel and warfarin (Prasugrel+OAC group); aspirin and warfarin (Aspirin+OAC group); prasugrel, aspirin, and warfarin group (Triple group); prasugrel and aspirin (Conventional DAPT group); and no medication (Control group). The treated groups were administered medication for 1 week. An arteriovenous shunt loop was established from the rabbit carotid artery to the jugular vein and 2 bare metal stents were deployed in a silicone tube. After 1 h of circulation, the volume of thrombi was evaluated quantitatively by measuring the amount of protein. Bleeding time was measured at the same time. The volume of the thrombus (amount of protein) around stent struts was lowest in the Triple group, followed by the Prasugrel+OAC and Conventional DAPT groups, and was highest in the Control group. Bleeding time was the longest in the Triple group, followed by the Aspirin+OAC, Prasugrel+OAC, Conventional DAPT, and Control groups. Conclusions: This study suggests that prasugrel with OAC may be a feasible antithrombotic regimen following stent implantation in patients who require OAC therapy.