Recruiting
Phase 3

Apixaban vs. Aspirin

Sponsor:

Texas Cardiac Arrhythmia Research Foundation

Code:

NCT07840365

Conditions

Atrial Fibrillation (AF)

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Half-Dose of novel OAC

Low-dose ASA

Study Details

Brief summary:

Optimal antithrombotic therapy after percutaneous left atrial appendage occlusion (LAAO) to prevent device-related thrombosis (DRT) is not well established. The main aim of improving the drug strategy after appendage closure is to synergistically optimize the device-based thromboembolic (TE) prevention without increasing the risk of thrombus formation on device and bleeding events. Short-term dual antiplatelet therapy (DAPT) followed by long-term aspirin monotherapy is a strategy commonly prescribed after LAA occlusion. Nonetheless, a significant number of patients continues to suffer from major bleeding and device-related thrombosis (DRT). Recent data reported that, after percutaneous LAA occlusion, a significant activation of the coagulation system occurs, without evidence of a concomitant platelet activation \[1\]. However, OAC at full dose is not only contraindicated, but also potentially detrimental in patients with an indication for LAA occlusion, given their high bleeding risk and the resulting unsuitability to long term anticoagulation. Half-dose NOAC may provide improved protection against DRT and TE events, without increasing the risk of bleeding. The recent Assessment of Dual Antiplatelet Therapy Versus Rivaroxaban in AF Patients Treated with Left Atrial Appendage Closure (ADRIFT) study \[2\] reported a better control of thrombin generation in patients with half-dose rivaroxaban compared to DAPT. Additionally, in a prospective series of 555 AF patients, Della Rocca et al have documented long-term half-dose direct oral anticoagulants (DOAC) to be associated with significant reduction in the risk of the composite endpoint of DRT, TE and major bleeding events compared with a standard antiplatelet based antithrombotic therapy (2).

On the basis of these observations, we designed a randomized study to compare two antithrombotic regimens (long-term half-dose apixaban vs long-term aspirin after 45-days of full-dose apixaban) after successful Watchman implantation.

Conditions

Atrial Fibrillation (AF)

Study ID

NCT07840365

Start date

Sep 1, 2026

Status verified date

Sep, 2026

Completion date

Sep 30, 2029

Anticipated

Primary completion date

Dec 15, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • • Men and women ≥18 years of age;

  • Patients who underwent a clinically successful LAA closure procedure with a Watchman device (device implanted without procedural or bleeding complication) within a day or are scheduled to undergo the LAAO procedure
  • Paroxysmal, persistent, or permanent AF patients irrespective of prior antithrombotic treatment are eligible for randomization,
  • Written informed consent obtained from subject and ability for subject to comply with the requirements of the study.

Exclusion Criteria:

  • Two or more clinical characteristics at baseline (age≥80 years, body weight ≤60 kg, serum creatinine ≥1.5 mg/dL) requiring apixaban dosage adjustment;

  • Mechanical heart valves or valvular disease requiring surgery or interventional procedure;
  • Mandatory indication for dual antiplatelet therapy (e.g. recent stent) or single anti-platelet treatment (SAPT) (e.g. high coronary risk);
  • Any contra-indication or known allergy to aspirin or clopidogrel or apixaban;
  • Any mandatory indication for anticoagulation for a reason other than AF (e.g. Pulmonary embolism);
  • Ongoing major bleeding or complicated or recent (<72hours) major surgery;
  • Recent myocardial infarction (<6 weeks);
  • Recent TE event (<6 weeks)
  • Recent Intracranial bleeding (< 6 months);
  • Prasugrel or ticagrelor concomitant use
  • Participating in an investigational drug or another device trial within the previous 30 days;
  • High likelihood of being unavailable for follow-up or psycho-social condition making study participation impractical;
  • Pregnancy or within 48 hours post-partum or breast feeding women;
  • Patient under legal protection.

Study Design

Enrollment

234 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

active comparator: long-term half-dose apixaban (Group hdNOAC)

active comparator: long-term aspirin (Group ASA)

Interventions

Half-Dose of novel OAC

Half-dose of apixaban after LAAO

Low-dose ASA

Low-dose aspirin after LAAO

Primary outcome measure

  • Composite endpoint of DRT, TE and major bleeding events [ Time Frame: 3 years ]

Central Contacts and Locations

Central contacts

Sanghamitra Mohanty, MD MS

5125448198mitra.mohanty@stdavids.com

Angel Mayedo, MD

512-544-8198angel.mayedo@stdavids.com

Locations

Texas Cardiac Arrhythmia Institute, St. David's Medical Center

Recruiting

Austin, Texas, United States, 78705

Contacts

Mitra Mohanty, MD

5125448198Mitra.Mohanty@stdavids.com

Bryan MacDonald, MD

Bryan.macdonald@stdavids.com

Principal Investigator:

Andrea Natale

More Information

Sponsor

Texas Cardiac Arrhythmia Research Foundation

Last update posted

Sep 25, 2026

Last verified

Sep, 2026

Keywords

  • oral anticoagulation
  • Left atrial appendage occlusion
  • atrial fibrillation
  • Aspirin

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-26. This information was provided to ClinicalTrials.gov by Texas Cardiac Arrhythmia Research Foundation on 2026-09-25. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.