Using apixaban to prevent valve thrombosis after aortic valve replacement

Comparison of Apixaban and Aspirin for the Prevention of Latent Bioprosthetic Valve Thrombosis After Aortic Valve Replacement Surgery: Study Protocol for a Prospective Randomized Trial

Phase 4 Interventional Clinical Hospital Centre Zagreb · NCT06184113

This study is testing if the blood thinner apixaban can help prevent blood clots in older patients who have just had aortic valve replacement surgery.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment166 (estimated)
Ages65 Years and up
SexAll
SponsorClinical Hospital Centre Zagreb Academic / other
Locations1 site (Zagreb)
Trial IDNCT06184113 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of apixaban, an oral anticoagulant, in preventing latent thrombosis in patients who have undergone aortic valve replacement with bioprosthetic valves. The study is a prospective, open-label, randomized trial involving patients aged 65 and older who do not require long-term anticoagulation. Participants will be assigned to receive either apixaban or acetylsalicylic acid for three months post-surgery, with assessments of valve health conducted through echocardiography and computed tomography. The goal is to determine if apixaban is superior in reducing hypo-attenuated leaflet thickening, which is associated with thrombosis.

Who should consider this trial

Good fit: Ideal candidates are men and women aged 65 or older with aortic valve stenosis who are undergoing their first isolated aortic valve replacement with a rapid deployment bioprosthetic valve.

Not a fit: Patients who require long-term anticoagulation or have contraindications to anticoagulation or antiplatelet therapy will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved outcomes for patients undergoing aortic valve replacement by reducing the risk of valve thrombosis.

How similar studies have performed: While the approach of using apixaban in this context is novel, similar studies have shown promise in the use of anticoagulants for preventing thrombosis in other settings.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria

* Men and women aged 65 or older with aortic valve stenosis undergoing successful isolated first-time aortic valve replacement with a rapid deployment bioprosthetic valve
* Signed informed consent to participate in the research

Exclusion Criteria:

* Indication for long-term use of anticoagulant therapy
* Indication for dual antiplatelet therapy
* Contraindication to anticoagulation or antiplatelet therapy
* Inability to start the study drug within the planned randomization period
* History of atrial fibrillation
* Known hemorrhagic diathesis
* Presence of other significant heart pathology
* Prior open-heart surgery
* Presence of liver failure or other coagulopathy
* Aortic valve infective endocarditis
* Severe renal failure
* Allergy to iodine contrast

Where this trial is running

Zagreb

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Aortic Valve ReplacementAntithrombotic TherapyBioprosthetic Valve ThrombosisRapid Deployment Valves
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.