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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT04394546
Recruitment Status : Active, not recruiting
First Posted : May 19, 2020
Last Update Posted : February 26, 2024
Information provided by (Responsible Party):
Boston Scientific Corporation

Brief Summary:
The primary objective of this study is to determine if left atrial appendage closure (LAAC) with the WATCHMAN FLX device is a reasonable alternative to non-vitamin K oral anticoagulants in patients with non-valvular atrial fibrillation.

Condition or disease Intervention/treatment Phase
Atrial Fibrillation Stroke Bleeding Device: WATCHMAN FLX LAAC Device Drug: Non-Vitamin K Oral Anticoagulant Not Applicable

Detailed Description:
This study is a prospective, randomized, multi-center global investigation. Subjects will be randomized to either the WATCHMAN FLX Left Atrial Appendage Closure Device ("Device Group") or a commercially available non-vitamin K oral anticoagulant ("Control Group").

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 3000 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: WATCHMAN FLX Versus NOAC for Embolic ProtectION in in the Management of Patients With Non-Valvular Atrial Fibrillation
Actual Study Start Date : October 15, 2020
Estimated Primary Completion Date : December 2027
Estimated Study Completion Date : December 2027

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Device Group
Randomized to WATCHMAN FLX Left Atrial Appendage Closure Device
WATCHMAN FLX LAAC Device Implantation
Other Name: WATCHMAN FLX Left Atrial Appendage Closure Device

Active Comparator: Control Group
Randomized to non-vitamin K oral anticoagulant (NOAC)
Drug: Non-Vitamin K Oral Anticoagulant
Initiation or continuation of a NOAC drug
Other Name: NOAC

Primary Outcome Measures :
  1. WATCHMAN FLX is non-inferior (NI) for the occurrence of stroke, cardiovascular death, and systemic embolism [ Time Frame: 36-months ]

  2. WATCHMAN FLX is superior for non-procedural bleeding (ISTH major bleeding and clinically relevant non-major bleeding) [ Time Frame: 36-months ]

  3. WATCHMAN FLX is non-inferior (NI) for the occurrence of ischemic stroke and systemic embolism [ Time Frame: 60-months ]

Secondary Outcome Measures :
  1. The occurrence of ISTH major bleeding [ Time Frame: 60-months ]

  2. The occurrence of cardiovascular (CV) death, all stroke, systemic embolism (SE), and non-procedural bleeding (ISTH major bleeding and clinically relevant non-major bleeding) [ Time Frame: 60-months ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • The subject is of legal age to participate in the study per the laws of their respective geography
  • The subject has documented non-valvular atrial fibrillation (i.e., atrial fibrillation in the absence of moderate or greater mitral stenosis or a mechanical heart valve)
  • The subject has a calculated CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke or transient ischemic attack (TIA), vascular disease, age 65 to 74 years, sex category) score of 2 or greater for men and 3 or greater for women
  • The subject is deemed to be suitable for the protocol-defined pharmacologic regimens in both the test and control 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:

  • Subjects who are currently enrolled in another investigational study, except when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments
  • The subject requires long-term anticoagulation therapy for reasons other than AF-related stroke risk reduction, for example due to an underlying hypercoagulable state (i.e., even if the device is implanted, the subjects would not be eligible to discontinue OAC due to other medical conditions requiring chronic OAC therapy)
  • The subject is contraindicated or allergic to oral anticoagulation medication and/or aspirin
  • The subject is indicated for chronic P2Y12 platelet inhibitor therapy
  • The subject had or is planning to have any cardiac or non-cardiac intervention or surgical procedure within 30 days prior to or 60 days after implant (including, but not limited to: cardioversion, percutaneous coronary intervention (PCI), cardiac ablation, cataract surgery, etc.)
  • The subject had a prior stroke (of any cause, whether ischemic or hemorrhagic) or transient ischemic attack (TIA) within the 30 days prior to enrollment
  • The subject had a prior major bleeding event per ISTH definition within the 30 days 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
  • The subject has an active bleed
  • The subject has a reversible cause of AF or transient AF
  • The subject is absent of a left atrial appendage (LAA) or the LAA is surgically ligated
  • The subject has had a myocardial infarction (MI) documented in the clinical record as either a non-ST elevation MI (NSTEMI) or as an ST-elevation MI (STEMI), with or without intervention, within 30 days prior to enrollment
  • The subject has a history of atrial septal repair or has an atrial septal device (ASD)/patent foramen ovale (PFO) device
  • The subject has an implanted mechanical valve prosthesis in any position
  • The subject has a known contraindication to percutaneous catheterization procedure
  • The subject has a known contraindication to transesophageal echo (TEE)
  • The subject has a cardiac tumor
  • The subject has signs/symptoms of acute or chronic pericarditis.
  • The subject has an active infection
  • There is evidence of tamponade physiology
  • The subject has New York Heart Association Class IV Congestive Heart Failure at the time of enrollment
  • The subject is of childbearing potential and is, or plans to become, pregnant during the time of the study (method of assessment upon study physician's discretion)
  • The subject has a documented life expectancy of less than 3 years

Transthoracic Echo Exclusion Criteria:

  • The subject has left ventricular ejection fraction ( LVEF) < 30%
  • The subject has an existing pericardial effusion with a circumferential echo-free space > 5mm
  • The subject has a high-risk PFO with an atrial septal aneurysm excursion > 15mm or length > 15mm
  • The subject has significant mitral valve (MV) stenosis (i.e., MV area <1.5 cm2)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04394546

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Sponsors and Collaborators
Boston Scientific Corporation
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Study Chair: Marty Leon, MD New York-Presbyterian Heart Valve Center/Columbia University Irving Medical Center
Study Chair: Kenneth A Ellenbogen, MD Virginia Commonwealth University
Principal Investigator: Shephal Doshi, MD Pacific Heart Institute and Providence St. John's Health Center
Principal Investigator: Saibal Kar, MD HCA Healthhcare /Los Robles Health System
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Responsible Party: Boston Scientific Corporation Identifier: NCT04394546    
Other Study ID Numbers: S2437
First Posted: May 19, 2020    Key Record Dates
Last Update Posted: February 26, 2024
Last Verified: February 2024
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Supporting Materials: Study Protocol

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Additional relevant MeSH terms:
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Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes