Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07677410

Aspirin Monotherapy Versus Sequential Warfarin-Aspirin Therapy After TAVR in Patients With Pure Aortic Regurgitation

This multicenter randomized controlled trial evaluates antithrombotic strategies post-TAVR in severe aortic regurgitation patients without long-term anticoagulation. Patients are randomized 1:1 to aspirin 75-100 mg daily for 12 months versus warfarin (INR 2-3) for 6 months followed by aspirin for 6 months. Primary hypothesis: aspirin is superior for bleeding and non-inferior for death/thrombosis. Primary endpoint is a composite of death, stroke, thrombosis, MI, embolism, and major bleeding at 1 year. Sample size: 1172. Follow-up: 30 days, 6 months, 12 months.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥18 years.
  • Patients with severe aortic regurgitation (AR) who achieve technical success after TAVR using devices specifically indicated for AR (per VARC-3 criteria).
  • Trileaflet aortic valve anatomy.
  • No long-term anticoagulation indication (including but not limited to: atrial fibrillation, mechanical mitral valve prosthesis, deep vein thrombosis, pulmonary embolism, left ventricular thrombus, pulmonary hypertension, or coagulation disorders) as confirmed by the investigator.
  • Signed written informed consent and willingness to comply with randomization, study procedures, and follow-up.

Exclusion criteria

  • Need for oral anticoagulation or dual antiplatelet therapy, or need for oral or intravenous strong CYP3A inhibitors that cannot be paused during the study period.
  • Active pathological bleeding, subdural hematoma, or history of intracranial hemorrhage.
  • Ischemic stroke within 30 days before TAVR.
  • Acute myocardial infarction within 30 days.
  • Severe hepatic insufficiency (cirrhosis, hepatic decompensation).
  • Severe renal insufficiency (eGFR < 30 mL/min/1.73 m²) or need for renal replacement therapy.
  • Stent implantation (including coronary, carotid, or peripheral arteries) within 12 months before TAVR, or planned stent implantation within 1 year after TAVR.
  • Coronary artery bypass grafting (CABG) within 12 months before TAVR.
  • Allergy, intolerance, or known resistance to aspirin, clopidogrel, or warfarin.
  • Known coagulation disorders or bleeding diathesis (including but not limited to platelet count ≤50,000/mm³ at screening).
  • Any contraindication to anticoagulation therapy.
  • Prior aortic valve prosthesis (mechanical or bioprosthetic); mitral valve bioprosthesis replacement within 1 year before TAVR; or prior mitral mechanical valve replacement; or prior tricuspid valve replacement.
  • Emergency TAVR with cardiogenic shock manifesting as low cardiac output, vasopressor or respiratory dependence, or mechanical hemodynamic support.
  • Life expectancy <1 year (e.g., terminal malignancy).
  • Participation in another investigational drug or device clinical study (patients who have completed the primary endpoint of the study and are currently in long-term follow-up are not excluded).
  • Pregnancy or planned pregnancy, or use of estrogen or estrogen-like drugs (for women with suspected pregnancy, serum or urine human chorionic gonadotropin test must be negative before enrollment).
  • Any other condition deemed by the investigator to be inappropriate for study participation.

Treatment and study plan

Aspirin

Drug

Aspirin 75-100 mg orally once daily

Warfarin

Drug

Warfarin orally with dose adjusted to maintain INR 2-3

Primary outcomes

  1. Number of Participants Who Experienced Non-hierarchical Composite Endpoint

    Time frame: 12 months post-procedure

    The primary endpoint is a non-hierarchical composite endpoint including all-cause death, stroke, prosthetic valve thrombosis, intracardiac thrombosis, myocardial infarction, deep vein thrombosis or pulmonary embolism, systemic embolism, and life-threatening, disabling, or major bleeding (VARC-3 definition).

Secondary outcomes

  1. Number of Participants Who Experienced Composite Endpoint of All-Cause Death, Ischemic Stroke, Valve/Intracardiac Thrombosis, and Myocardial Infarction.

    Time frame: 12 months post-procedure

    The first key secondary endpoint is composite of all-cause death, ischemic stroke, valve/intracardiac thrombosis, and myocardial infarction.

  2. Number of Participants Who Experienced Composite of Life-threatening, Disabling, or Major Bleeding (based on VARC-3 criteria Type 2-4)

    Time frame: 12 months post-procedure

    Life-threatening or disabling bleeding Fatal bleeding OR Bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, or pericardial necessitating pericardiocentesis, or intramuscular with compartment syndrome OR Bleeding causing hypovolemic shock or severe hypotension requiring vasopressors or surgery OR Overt source of bleeding with drop in haemoglobin of ≥5 g/dL or whole blood or packed red blood cells (RBCs) transfusion ≥4 unitsa

    Major bleeding Overt bleeding either associated with a drop in the haemoglobin level of at least 3.0 g/dL or requiring transfusion of two or three units of whole blood/RBC AND Does not meet criteria of life-threatening or disabling bleeding

  3. Number of Participants Who Experience Composite of Cardiovascular Death, Major Bleeding, Stroke, and Myocardial Infarction

    Time frame: 12 months post-procedure

  4. Number of Participants Who Experience Clinical Efficacy Composite Endpoint

    Time frame: 12 months post-procedure

    Composite endpoint requiring all of the following: freedom from all-cause death; freedom from all stroke; no hospitalization for valve-related or procedure-related reasons; and KCCQ overall score ≥45 with no more than a 10-point decrease from baseline.

  5. Number of Participants Who Experienced All-Cause Death

    Time frame: 12 months post-procedure

  6. Number of Participants Who Experience Clinically Significant Prosthetic Valve Thrombosis (VARC-3)

    Time frame: At 6 months and 12 months post-procedure

    Based on VARC-3 criteria, clinically significant prosthetic valve thrombosis defined as clinical. sequelae of a thromboembolic event (e.g. stroke, TIA, retinal occlusion, other evidence of systemic thromboembolism) or worsening valve stenosis/ regurgitation (e.g. signs of heart failure, syncope) and Haemodynamic valve deterioration Stage 2 or 3 or Confirmatory imaging (CT evidence of HALT or TEE findings) In the absence of clinical sequelae, both Haemodynamic valve deterioration Stage 3 and Confirmatory imaging (CT evidence of HALT or TEE findings)

  7. Number of Participants Who Experience Bioprosthetic Valve Deterioration Stage 3 by Echocardiography (VARC-3)

    Time frame: 12 months post-procedure

    Bioprosthetic Valve Failure Stage 3 defined as increase in mean transvalvular gradient ≥20 mmHg resulting in mean gradient ≥30 mmHg with concomitant decrease in EOA ≥0.6 cm2 or ≥50% and/or decrease in Doppler velocity index ≥0.2 or ≥40% compared with echocardiographic assessment performed 1-3 months post-procedure, OR new occurrence, or increase of ≥2grades, of intraprosthetic AR resulting in severe AR

  8. Number of Participants Who Experience Hypo-Attenuated Leaflet Thickening (HALT) by CT

    Time frame: 12 months post-procedure

  9. Number of Participants Who Experienced Non-Procedure-Related Life-Threatening or Disabling Bleeding (VARC-3)

    Time frame: At 30 days and 12 months post-procedure

  10. Number of Participants Who Experienced Major Bleeding

    Time frame: At 30 days and 12 months post-procedure

    Based on VARC 2 criteria

  11. Number of Participants Who Experienced Minor Bleeding

    Time frame: At 30 days and 12 months post-procedure

    Based on VARC 2 criteria

  12. Number of Participants Who Experienced Aortic Valve Re-Intervention

    Time frame: 12 months post-procedure

  13. Number of Participants Who Experienced Heart Failure Re-Hospitalization

    Time frame: 12 months post-procedure

  14. Number of Participants Who Experienced Infective Endocarditis

    Time frame: 12 months post-procedure

    Infective Endocarditis defined as:

    Meeting at least one of the following criteria:

    Fulfills the Duke criteria for endocarditis; Intraoperative evidence of an abscess, pus, or vegetation secondary to infection, confirmed by histology or microbiology; Autopsy evidence of an abscess, pus, or vegetation.

  15. Number of Participants Who Experienced Major Adverse Cardiovascular and Cerebrovascular Events (MACCE)

    Time frame: At 30 days and 12 months post-procedure

    MACCE including cardiac death, aortic valve reintervention, stroke, myocardial infarction, heart failure readmission and life-threatening, disabling, or major bleeding.

  16. Number of Participants Who Experienced NYHA Class Improvement

    Time frame: At 30 days and 12 months post-procedure

Study contacts

Contact information is provided by the study sponsor or research team.

Lai Wei, MD

CONTACT

[email protected]

+86-021-64041990

Sponsors and collaborators

Lead sponsor

Shanghai Zhongshan Hospital

Other

Collaborators

  • Suzhou Jiecheng Medical Technology Co., Ltd.

Registry information

Official study title

Prospective, Multicenter, Randomized Controlled Trial Evaluating the Safety and Efficacy of Different Antithrombotic Therapy Strategies in Patients With Severe Aortic Regurgitation Undergoing Transcatheter Aortic Valve Replacement

Acronym: AWATAR

Important dates

Study start
2026
Primary completion
2029
Study completion
2030
First posted
Jun 30, 2026
Registry last updated
Jul 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.