Clinical trial Recruiting at 13 sites Phase 4 Interventional Ages 19 and up

Comparing blood thinners after mechanical aortic valve replacement

Official title: Randomized, Evaluation of Long-term Anticoagulation With Oral Factor Xa Inhibitor Versus Vitamin K Antagonist After Mechanical Aortic Valve Replacement

Run by Asan Medical Center · NCT04258488 · Data updated 2026-11-12

This study tests whether a new blood thinner called rivaroxaban works better than the traditional warfarin for people who have had a mechanical aortic valve replacement.

Quick facts

PhasePhase 4
Study typeInterventional
Ages19 Years and up
SexAll
Enrollment1300 (estimated)
SponsorAsan Medical Center
Academic / other
Locations16 sites (Bucheon-si and 15 other locations)
StatusRecruiting
StartedFebruary 21, 2022
Main results expectedDecember 31, 2027
Study endsDecember 30, 2028
Registry record updatedJuly 6, 2026
Trial IDNCT04258488 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates for this study are adults aged 19 and older who have undergone mechanical aortic valve replacement at least three months prior and meet specific functional and valve performance criteria.

Probably not a fit

Patients with old-generation mechanical valves, significant mitral valve issues, or recent history of stroke may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study evaluates the effectiveness of long-term anticoagulation using an oral factor Xa inhibitor, specifically rivaroxaban, compared to the traditional vitamin K antagonist, warfarin, in patients who have undergone mechanical aortic valve replacement. The trial focuses on patients who are at least three months post-surgery and meet specific functional and valve performance criteria. By assessing the outcomes of these two anticoagulation methods, the study aims to determine which is more beneficial for preventing thromboembolism in this patient population.

Why it matters

Potential benefit: If successful, this study could provide patients with a more effective and safer anticoagulation option after mechanical aortic valve replacement.

How similar studies have gone: Other studies have shown promising results with factor Xa inhibitors in similar settings, suggesting potential for success in this approach.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age 19 and more
2. At least 3 months after mechanical aortic valve replacement
3. At least one of the conditions(as defined below) is met

   * The New York Heart Association (NYHA) Functional Classification I or II; or
   * According to the Valve Academic Research Consortium(VARC)2 criteria, confirmed proper valve function: no prosthesis-patient mismatch and mean aortic valve gradient \<20 mm Hg or peak velocity \<3 m/s, AND no moderate or severe prosthetic valve regurgitation
4. Voluntarily participated in the written agreement

Exclusion Criteria:

1. Old-generation mechanical valve
2. History of mechanical valve implantation in the mitral valve, pulmonary valve, or tricuspid valve
3. Valvular atrial fibrillation(atrial fibrillation with moderate or severe mitral stenosis)
4. Moderate to severe mitral stenosis or regurgitation
5. History of hemorrhagic stroke
6. Clinically overt stroke within the last 3 months
7. Renal failure(creatinine clearance \<15mL/min) or on hemodialysis
8. Left ventricular dysfunction: Left ventricular ejection fraction (LVEF) ≤40%
9. Child-Pugh B and C hepatic impairment or any hepatic disease associated with coagulopathy
10. Clinically significant active bleeding
11. Bleeding or hemorrhagic disorder
12. The increased risk of bleeding due to the following reasons

    1. History of gastrointestinal ulcers or active ulcerations within the last 6 months
    2. History of intracranial or intracerebral hemorrhage within the last 6 months
    3. Spinal cord vascular abnormalities or intracerebral vascular abnormalities
    4. History of the brain, spinal cord, or ophthalmic surgery within the last 6 months
    5. History of the brain or spinal cord injury within the last 6 months
    6. History of the brain or spinal cord injury or spinal tap, major regional anesthesia, or spinal anesthesia within the last 6 months
    7. Esophageal varices
    8. Arteriovenous malformation
    9. Vascular aneurysms
    10. Malignant tumor with a high risk of bleeding
13. Bleeding tendencies associated with overt bleeding of

    1. gastrointestinal, genitourinary, respiratory tract, or colorectal cancer
    2. cerebrovascular hemorrhage
    3. aneurysms- cerebral, dissecting aorta
    4. pericarditis and pericardial effusions
    5. bacterial endocarditis
14. Hemodynamically unstable or pulmonary embolism required thrombolysis or embolectomy
15. Combination therapy with other anticoagulants(Unfractionated heparin(UFH), enoxaparin, dalteparin, fondaparinux, etc.) However, the following cases are permitted

    * Switching anticoagulants
    * Intravenous UFH to keep central/arterial lines open
16. Uncontrolled moderate or severe hypertension
17. Anemia at least one among the conditions(as defined below) is met 1) Hemoglobin level \<10.0 g/dL or platelet count \< 100 x 10x9/L within the last 6 months 2) Diagnosed and documented ongoing anemia
18. Infective endocarditis
19. Hypersensitivity to the main component or constituents of Rivaroxaban or Vitamin K antagonist
20. Positive pregnancy test results (all pregnant women should undergo urinary human chorionic gonadotropin (hCG) testing within 7 days before screening and/or randomization) or during pregnancy or lactation
21. A genetic problem with galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption
22. The unsuitable condition of the protocol
23. Actively participating in another drug or device investigational study, which has not completed the primary endpoint follow-up period
24. Terminal illness with life expectancy \<12 months
25. Vitamin K deficiency
26. Alcoholic or psychical disorder
27. Threatened abortion, eclampsia, or preeclampsia
28. Concomitant use with antiplatelet in patients with a history of stroke or transient ischemic attack for the treatment of the acute coronary syndrome

Where it's running

  • Buchen Sejong Hospital
    Bucheon-si, South Korea
    Recruiting
  • Dong-A University Hospital
    Busan, South Korea
    Recruiting
  • Keimyung University Dongsan Hospital
    Daegu, South Korea
    Recruiting
  • GangNeung Asan Hospital
    Gangneung, South Korea
    Recruiting
  • Chonnam National University Hospital
    Gwangju, South Korea
    Recruiting
  • Seoul National University Bundang Hospital
    Seongnam, South Korea
    Recruiting
Show 10 more locations
  • Asan Medical Center
    Seoul, South Korea
    Recruiting
  • Korea University Anam Hospital
    Seoul, South Korea
    Recruiting
  • Samsung Medical Center
    Seoul, South Korea
    Recruiting
  • Seoul National University Hospital
    Seoul, South Korea
    Recruiting
  • Ajou University Hospital
    Suwon, South Korea
    Recruiting
  • Eulji University Uijeongbu Hospital
    Uijeongbu-si, South Korea
    Recruiting
  • Pusan National University Yangsan Hospital
    Yangsan, South Korea
    Recruiting
  • Severance Hospital
    Seoul, South Korea
    Not yet recruiting
  • St. Vincent's Hospital, Catholic University of Korea
    Suwon, South Korea
    Not yet recruiting
  • Ulsan University Hospital
    Ulsan, South Korea
    Not yet recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

  • Vericiguat to slow calcific aortic valve narrowing

    This trial tests whether vericiguat can slow the progression of mild-to-moderate calcific aortic valve stenosis compared with placebo.

    Recruiting Phase 2 West China Hospital · Chengdu, Sichuan · NCT07715279

  • Tailored lower‑intensity blood thinner plan after left atrial appendage closure to prevent stroke

    This project tests whether people with non‑valvular atrial fibrillation who get a left atrial appendage closure can stop blood thinners after taking low‑dose apixaban (2.5 mg twice daily) for 3 months, compared with people who stay on standard‑dose DOACs.

    Recruiting National Medical Research Center for Therapy and Preventive Medicine · Moscow · NCT07575867

  • Surgical implantation of a polymer prosthetic mitral or aortic valve

    This will test a surgically implanted polymer heart valve to see if it is safe and works well for adults who need mitral or aortic valve replacement.

    Recruiting Mitrassist Lifesciences Limited Co., Ltd. · Shanghai, Shanghai Municipality · NCT07097740

  • Cardiovascular risk in people with Crohn's disease and ulcerative colitis

    This study tests whether people with inflammatory bowel disease have different heart-attack or stroke risk over two years compared with matched controls.

    Recruiting IRCCS Policlinico S. Donato · San Donato Milanese, Milan · NCT07095634

  • Sapien 3 TAVR for younger adults with aortic stenosis in China

    This project tries the Sapien 3 transcatheter aortic valve replacement (TAVR) in people aged 50–70 with severe aortic stenosis, including bicuspid valves, to see if it is safe, effective, and durable.

    Recruiting at 2 sites Xijing Hospital · Xi'an, Shaanxi and 3 other locations · NCT06830499

  • Transfemoral VitaFlow Liberty treatment for pure aortic regurgitation

    This trial will test whether replacing the aortic valve through the leg with the VitaFlow Liberty valve plus usual medical care helps people aged 60 and older with moderate-to-severe or worse isolated aortic regurgitation.

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How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 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.