PROACT Xa - A Trial to Determine if Participants With an On-X Aortic Valve Can be Maintained Safely on Apixaban

There is an unmet clinical need for an alternative to warfarin, such as a direct oral anticoagulant (DOAC), as anticoagulation in participants with an aortic mechanical prosthetic valve. Some participants may be genetically hyper- or hypo-responsive to warfarin, which makes management difficult. Another small group of participants is allergic to warfarin. A much larger group of participants has difficulty maintaining warfarin control due to dietary and drug interactions. Finally, the requirement for routine blood testing makes people reluctant to take warfarin. All of these factors drive younger participants in need of aortic valve replacement (AVR) toward selection of a tissue valve instead of a mechanical valve. Despite multiple studies (randomized, matched and risk adjusted) that show that tissue valves are associated with worse outcomes, younger participants choose this type of valve to avoid warfarin. In addition, multiple clinical studies have shown valve reoperation rates are higher for tissue valves used in these younger participants. Providing an alternative to warfarin anticoagulation may lead younger participants to choose a mechanical valve with greater durability and better clinical outcomes.