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Comparing different medication regimens after WATCHMAN FLX Pro device implantation

WATCHMAN FLX™ Pro Left Atrial Appendage Closure Device With Alternative Post-Implant Monotherapy

Not applicable Interventional Boston Scientific Corporation · NCT06521463

This study is testing which of three different medication plans is safest and most effective for people with atrial fibrillation after getting the WATCHMAN FLX Pro device implanted.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment1857 (estimated)
Ages18 Years and up
SexAll
SponsorBoston Scientific Corporation Industry-sponsored
Locations66 sites (Birmingham, Alabama and 65 other locations)
Trial IDNCT06521463 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the safety and effectiveness of three different medication regimens following the implantation of the WATCHMAN FLX Pro device in patients with atrial fibrillation. Participants will be randomly assigned to one of three treatment arms: aspirin only, a reduced dose of a non-vitamin K antagonist oral anticoagulant, or dual antiplatelet therapy. The study will follow participants for 12 months to assess outcomes related to stroke and bleeding. It is a multi-center, open-label trial designed to provide insights into optimal post-implantation care.

Who should consider this trial

Good fit: Ideal candidates for this study are adults who are suitable for the WATCHMAN FLX Pro device and can adhere to the required medication regimens.

Not a fit: Patients who have experienced complications during the device implant procedure or have contraindications to the study medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help identify the most effective medication regimen for patients after receiving the WATCHMAN FLX Pro device, potentially reducing the risk of stroke and bleeding.

How similar studies have performed: Previous studies have explored various anticoagulation strategies in atrial fibrillation, but this specific comparison of monotherapy versus dual therapy post-WATCHMAN implantation is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Subject is of legal age to participate in the study per the laws of their respective geography.
* Subject is an acceptable candidate for a WATCHMAN FLX Pro device per the approved Instructions for Use.
* Subject is deemed to be suitable for all protocol defined drug regimens in the control and both test arms.
* The subject or legal representative is able to understand and willing to provide written informed consent to participate in the trial.
* The subject is able and willing to return for required follow-up visits and examinations.

Exclusion Criteria:

* Subject's device implant procedure was aborted (i.e., failed implant).
* Subject has a device margin residual leak \> 0mm at time of implant.
* Occurrence of complications (major bleeding, systemic embolism, stroke, pericardial effusion requiring intervention) during the implant procedure, post-procedure, or prior to randomization.
* Subject has a contraindication to one of the three protocol defined drug regimens.
* Subject requires long-term anticoagulation therapy for reason other than AF-related stroke risk reduction or requires chronic P2Y12 inhibitor therapy.
* Subject has known history of severe liver disease including cirrhosis with a Child-Pugh classification C or D.
* Subject with known hypercoagulability disorder, mechanical heart valve, rheumatic heart disease, or recurrent deep vein thrombosis.
* Subject has intracardiac thrombus, LAA sludge, or dense spontaneous echo contrast (SEC) observed during pre-implant imaging.
* Subject has Modified Rankin Score of ≥ 3 at baseline.
* Subject has left ventricular ejection fraction (LVEF) \< 30%.
* Subject with known amyloid cardiomyopathy.
* Platelet count ≤ 100,000 x 109/L.
* Subject has an estimated glomerular filtration rate (eGFR) \< 30 ml/min (chronic kidney disease stage IV or V) or is on dialysis.
* Subject has a stroke (of any cause, whether ischemic or hemorrhagic) within 30 days prior to implant or prior to randomization.
* Subject has a documented myocardial infarction (MI) as either a non-ST elevation MI (NSTEMI) or as an ST-elevation MI (STEMI), with or without intervention, within 30 days prior to implant or prior to randomization.
* Subject had or is planning to have any cardiac or non-cardiac intervention or surgical procedure within 30 days prior to or 6-months after implant (including, but not limited to, cardioversion, percutaneous coronary intervention, cardiac ablation, cataract surgery, etc.).
* Subject has a major bleeding event per International Society on Thrombosis and Haemostasis (ISTH) definitions within the 30 days prior to implant or prior to randomization. Lack of resolution of related clinical sequelae or planned and pending interventions to resolve bleeding/bleeding source are a further exclusion regardless of timing of the bleeding event.
* Subject has an active bleed.
* Subject has a cardiac tumor.
* Subject has signs/symptoms of acute or chronic pericarditis.
* Subject has an active infection.
* There is evidence of tamponade physiology.
* Subject has New York Heart Association Class IV congestive heart failure at the time of implant or prior to randomization.
* Subject is currently enrolled in another investigational study, except if the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatment.
* Subject is of childbearing potential and is, or plans to become, pregnant during the time of the study.
* Subject has a documented life expectancy of less than 12 months.

Where this trial is running

Birmingham, Alabama and 65 other locations

+16 more sites — see ClinicalTrials.gov for the full list.

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.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Atrial FibrillationStrokeBleeding
Last reviewed 2026-06-15 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.