Clinical Trial: Surgery


Full Name

A prospective, randomized, active(warfarin) controlled, parallel-arm clinical trial to determine if patients with an On-X aortic valve can be maintained safely and effectively on the factor Xa inhibitor apixaban


Purpose: The purpose of the study is to determine if participants with an ON-X Prosthetic Heart Valve/ ON-X aortic valve (a type of mechanical valve) can be maintained safely and effectively on apixaban, an anticoagulant drug different from warfarin. Enrollment in the study is for at least 2 years until the last participant has completed 2 years of follow up.


People with an On-X valve in the aortic valve position should be maintained on long-term anticoagulation to prevent mechanical valve-related clotting (thrombosis) and other clotting complications (thromboembolism), including stroke. It is unknown whether apixaban is as good as warfarin at preventing these effects in patients with an On-X mechanical aortic valve. There may be a risk of other complications besides valve thrombosis and thromboembolic stroke. Detailed information about the known and expected benefits and risks and reasonably expected adverse events of apixaban may be discussed with your study doctor

Participants who qualify for the Clinical trial will be randomized to either apixaban or to remain on warfarin treatment. The randomization is a 1:1 ratio, so you will have a 50/50 chance (like flipping a coin) in determining your treatment.


Inclusion Criteria
  • Greater than 18 years of age
  • Able to receive warfarin with a target INR 2.0 to 3.0.
  • Able to take low-dose aspirin at a dose of 75 -100 mg daily or have a documented
  • contraindication to aspirin use.
  • Implantation of an On-X mechanical valve in the aortic position at least 3 months (90 days) prior to enrollment
  • Able to provide written informed consent.

To Participate:
Please contact the Network Office of Research and Innovation at 610-402-9543

For additional information:

Doctor(s) Running This Study