SIMPLAAFY Clinical Trial (SIMPLAAFY)

August 6, 2026 updated by: Boston Scientific Corporation

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

The primary objective is to demonstrate the safety and effectiveness of two monotherapy regimens versus dual antiplatelet (DAPT) therapy following post-implant with the WATCHMAN FLX Pro device in a commercial clinical setting.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a prospective, randomized, open-label, triple-arm, multi-center trial. Subjects will be randomized 1:1:1 to one of the three therapy arms and remain on treatment through the end of study (12 months):

  1. Aspirin only
  2. Reduced dose non-vitamin K antagonist (VKA) oral anticoagulant (NOAC)
  3. DAPT

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
1857

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35243
        • Grandview Medical Center
      • Birmingham, Alabama, United States, 35233
        • University of Alabama Birmingham
    • Arizona
      • Phoenix, Arizona, United States, 85018
        • Phoenix Cardiovascular Research Group
      • Scottsdale, Arizona, United States, 85258
        • HonorHealth Heart Group - Shea
      • Tucson, Arizona, United States, 85712
        • Tucson Medical Center Healthcare
    • Arkansas
      • Jonesboro, Arkansas, United States, 72401
        • Arrhythmia Research Group
    • California
      • Burlingame, California, United States, 94010
        • Mills Peninsula Health Services
      • Concord, California, United States, 94520
        • John Muir Medical Center
      • La Jolla, California, United States, 92037
        • Scripps Memorial Hospital
      • Loma Linda, California, United States, 92354
        • Loma Linda University Medical Center
      • Los Angeles, California, United States, 90404
        • St. John's Health Center
      • Santa Barbara, California, United States, 93105
        • Santa Barbara Cottage Hospital
      • Thousand Oaks, California, United States, 91360
        • Los Robles Hospital & Medical Center
      • Ventura, California, United States, 93003
        • Cardiology Associates Medical Group
    • Colorado
      • Lakewood, Colorado, United States, 80401
        • Colorado Heart and Vascular PC
      • Loveland, Colorado, United States, 80538
        • Medical Center of the Rockies
    • Connecticut
      • Hartford, Connecticut, United States, 06102
        • Hartford Hospital
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20010
        • Washington Hospital
    • Florida
      • Jacksonville, Florida, United States, 32207
        • Baptist Medical Center
      • Naples, Florida, United States, 34102
        • Naples Community Hospital
      • Sarasota, Florida, United States, 34239
        • Sarasota Memorial Hospital
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • Emory University Hospital
      • Macon, Georgia, United States, 31201
        • Georgia Arrhythmia Consultants
      • Marietta, Georgia, United States, 30060
        • Wellstar Kennestone Hospital
      • Savannah, Georgia, United States, 31405
        • Memorial Health University Medical Center
    • Hawaii
      • Honolulu, Hawaii, United States, 96813
        • Straub Medical Center
    • Idaho
      • Boise, Idaho, United States, 83712
        • St. Luke's Boise Medical Center
      • Coeur d'Alene, Idaho, United States, 83814
        • Kootenai Medical Center
    • Illinois
      • Evanston, Illinois, United States, 60201
        • Evanston Hospital
      • Naperville, Illinois, United States, 60540
        • Midwest Cardiovascular Institute
      • Oak Lawn, Illinois, United States, 60453
        • Advocate Christ Medical Center
    • Indiana
      • Indianapolis, Indiana, United States, 46250
        • Community Heart and Vascular Hospita
    • Iowa
      • Des Moines, Iowa, United States, 50266
        • Mercy Hospital Medical Center
      • Iowa City, Iowa, United States, 52242
        • University of Iowa Hospitals and Clinics
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • University of Kansas
    • Kentucky
      • Lexington, Kentucky, United States, 40503
        • Baptist Health Lexington
      • Louisville, Kentucky, United States, 40202
        • Norton Hospital
    • Massachusetts
      • Fall River, Massachusetts, United States, 02720
        • Charlton Memorial
      • Worcester, Massachusetts, United States, 01655
        • University of Massachusetts Memorial Medical Center
    • Michigan
      • Ann Arbor, Michigan, United States, 48106
        • St. Joseph Mercy Hospital
      • Detroit, Michigan, United States, 48202
        • Henry Ford Hospital
      • Grand Rapids, Michigan, United States, 49503
        • Corewell Health
    • Minnesota
      • Maplewood, Minnesota, United States, 55109
        • M Health Fairview St John's Hospital
      • Rochester, Minnesota, United States, 55902
        • Mayo Clinic Foundation
      • Saint Cloud, Minnesota, United States, 56303
        • Centracare Heart and Vascular Center
    • Mississippi
      • Jackson, Mississippi, United States, 39216
        • University of Mississippi Medical Center
      • Tupelo, Mississippi, United States, 38801
        • North Mississippi Medical Center
    • Missouri
      • Kansas City, Missouri, United States, 64111
        • St. Luke's Hospital of Kansas City
      • St Louis, Missouri, United States, 63141
        • St. Luke's Hospital
    • New Hampshire
      • Lebanon, New Hampshire, United States, 03756
        • Dartmouth Hitchcock Medical Center
    • New Jersey
      • Camden, New Jersey, United States, 08103
        • Cooper Hospital - University Medical Center
      • Marlton, New Jersey, United States, 08053
        • Virtua Health
      • Paramus, New Jersey, United States, 07652
        • Valley Hospital
    • New Mexico
      • Albuquerque, New Mexico, United States, 87102
        • Lovelace Medical Center
    • New York
      • Bay Shore, New York, United States, 11706
        • Northwell Health
      • Buffalo, New York, United States, 14203
        • Kaleida Health
      • New York, New York, United States, 10016
        • New York University Medical Center
      • The Bronx, New York, United States, 10467
        • Montefiore Medical Center
    • North Carolina
      • Charlotte, North Carolina, United States, 28204
        • Novant Health Presbyterian Medical Center
      • Charlotte, North Carolina, United States, 28203
        • Carolinas Medical Center
      • Raleigh, North Carolina, United States, 27610
        • Wake Medical Center
      • Raleigh, North Carolina, United States, 27607
        • Rex Hospital
    • Ohio
      • Cincinnati, Ohio, United States, 45242
        • Bethesda North Hospital-Hospital
      • Cleveland, Ohio, United States, 44106
        • University Hospitals of Cleveland
      • Columbus, Ohio, United States, 43210
        • Ohio State University Medical Center
    • Oregon
      • Portland, Oregon, United States, 97227
        • Legacy Emanuel Hospital & Health Center
    • Pennsylvania
      • Harrisburg, Pennsylvania, United States, 17101
        • Pinnacle Health at Harrisburg Hospital
    • South Carolina
      • Charleston, South Carolina, United States, 29406
        • Trident Medical Center
      • Columbia, South Carolina, United States, 29203
        • Prisma Health
      • Columbia, South Carolina, United States, 29204
        • MUSC Health Columbia Medical Center Downtown
    • Tennessee
      • Germantown, Tennessee, United States, 38138
        • Stern Cardiovascular Foundation
      • Nashville, Tennessee, United States, 37203
        • St. Thomas Heart
    • Texas
      • Austin, Texas, United States, 78705
        • Texas Cardiac Arrhythmia Research
      • Houston, Texas, United States, 77024
        • Memorial Hermann Memorial City Medical Center
      • Houston, Texas, United States, 77034
        • Orion Medical
      • San Antonio, Texas, United States, 78229
        • Methodist Hospital
      • Tyler, Texas, United States, 75702
        • Christus Trinity Mother Frances Health System-Hospital
    • Utah
      • Salt Lake City, Utah, United States, 84124
        • St. Mark's Hospital
    • Virginia
      • Norfolk, Virginia, United States, 23507
        • Sentara Norfolk General Hospital
      • Richmond, Virginia, United States, 23235
        • Chippenham & Johnston-Willis Hospital
      • Roanoke, Virginia, United States, 24014
        • Carilion Roanoke Memorial Hospital
    • Washington
      • Bellevue, Washington, United States, 98004
        • Overlake Hospital Medical Center
      • Seattle, Washington, United States, 98195
        • University of Washington Medical Center
    • West Virginia
      • Morgantown, West Virginia, United States, 26505
        • Monongalia General Hospital
    • Wisconsin
      • Green Bay, Wisconsin, United States, 54305
        • Bellin Health
      • Milwaukee, Wisconsin, United States, 53226
        • Froedtert Memorial Lutheran Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Aspirin
Aspirin 81-100 mg, daily post implant for duration of the clinical trial
Device: WATCHMAN FLX Pro LAAC Device
WATCHMAN FLX Pro LAAC Device Implantation
Other Names:
  • WATCHMAN FLX Pro Left Atrial Appendage Closure Device
Experimental: Reduced dose non-vitamin K antagonist (VKA) oral anticoagulant (NOAC)
Reduced dose non-vitamin K antagonist (VKA) oral anticoagulant (NOAC) for the first 3 months daily, post implant, followed by aspirin only for the duration of the clinical trial
Device: WATCHMAN FLX Pro LAAC Device
WATCHMAN FLX Pro LAAC Device Implantation
Other Names:
  • WATCHMAN FLX Pro Left Atrial Appendage Closure Device
Active Comparator: DAPT
DAPT (aspirin 81-100 mg + clopidogrel 75 mg), for the first 6-months daily followed by aspirin only for the duration of the clinical trial
Device: WATCHMAN FLX Pro LAAC Device
WATCHMAN FLX Pro LAAC Device Implantation
Other Names:
  • WATCHMAN FLX Pro Left Atrial Appendage Closure Device

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Reduced dose NOAC Arm Primary Endpoint: Composite rate of all death, all stroke, systemic embolism, and ISTH major bleeding at 6-months after randomization in the reduced dose NOAC arm tested for non-inferiority compared to the DAPT arm
Time Frame: 6 months after randomization
Non Inferiority
6 months after randomization
Aspirin Arm Primary Endpoint: Composite rate of all death, all stroke, systemic embolism, and ISTH major bleeding at 6-months after randomization in the Aspirin arm tested for non-inferiority compared to the DAPT arm.
Time Frame: 6 months after randomization
Non Inferiority
6 months after randomization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Boston Scientific Corporation

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Walid Saliba, MD, The Cleveland Clinic
  • Study Chair: Vivek Reddy, MD, Icahn School of Medicine at Mount Sinai
  • Principal Investigator: Saibal Kar, MD, Los Robles Health System

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 7, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 22, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 22, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 26, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • S2508

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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