Artivion, Inc. announced that it has stopped the PROACT Xa clinical trial, a prospective, randomized, trial designed to determine if patients with an On-X mechanical aortic valve can be maintained safely and effectively on apixaban rather than on warfarin. The decision was based on the recommendation of the independent Data and Safety Monitoring Board (DSMB) of the trial due to lack of evidence supporting non-inferiority of apixaban to warfarin for valve thrombosis and thromboembolism. The PROACT Xa trial randomized patients having an On-X aortic valve replacement to receive either warfarin or apixaban as their anticoagulant to prevent blood clots.
The trial began enrolling in April 2020. The DSMB found that blood clots, resulting in stroke, occurred more frequently in patients receiving apixaban and that continuing the trial was unlikely to achieve the primary endpoint while possibly exposing patients to increased risk. Physician investigators at the trial's sites are being notified to change patients who are in the apixaban arm of the trial back to warfarin.