StrokeASAP-TOONCT02928497
Assessment of the WATCHMAN™ Device in Patients Unsuitable for Oral Anticoagulation
A study testing WATCHMAN LAAC Device Implant in people with Stroke, run by Boston Scientific Corporation at 92 sites in 9 countries.
Trial summary
The purpose of this study is to establish the safety and effectiveness of the WATCHMAN™ Left Atrial Appendage Closure (LAAC) Device, including the post-implant medication regimen, for subjects with non-valvular atrial fibrillation who are deemed not to be eligible for anti-coagulation therapy to reduce the risk of… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Stroke
- What is being tested?
- WATCHMAN LAAC Device Implant
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 481 participants
- Where
- 92 sitesin 9 countries
- Study dates
- 6 Feb 2017to 23 Sep 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The subject is of legal age to participate in the study per the laws of their respective geography.
- The subject has documented paroxysmal, persistent, permanent or long-term/longstanding persistent non-valvular atrial fibrillation (i.e., the subject has not been diagnosed with rheumatic mitral valvular heart disease).
- The subject has a calculated CHA2DS2-VASc score of 2 or greater.
- The subject is deemed by two study physicians to be unsuitable for oral anticoagulation.
- The subject is deemed by a study physician to be suitable for the defined protocol pharmacologic regimen of aspirin and clopidogrel therapy following WATCHMAN Closure Device implant.
- 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.
Who cannot join
- The subject is unable or unwilling to return for required follow-up visits and examinations.
- The subject had or is planning to have any invasive cardiac procedure within 30 days prior to randomization (e.g., cardioversion, ablation).
- The subject is planning to have any cardiac or non-cardiac invasive or surgical procedure that would necessitate stopping or modifying the protocol required medication regimen within 90 days after the WATCHMAN Closure Device implant (e.g., cardioversion, ablation, cataract surgery).
- The subject had a prior stroke (of any cause) or TIA within the 30 days prior to randomization.
- The subject had a prior BARC type 3 or 4 bleeding event within the 14 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 a history of atrial septal repair or has an ASD/PFO device.
Show all 13Show fewer
- The subject has an implanted mechanical valve prosthesis in any position.
- The subject suffers from New York Heart Association Class IV Congestive Heart Failure.
- The subject has LVEF < 30%.
- 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 is currently enrolled in another investigational study or registry that would directly interfere with the current study, except when the subject is participating in a mandatory governmental registry, or a purely observational registry with no associated treatments. Each instance should be brought to the attention of the sponsor to determine eligibility.
- The subject has a life expectancy of less than two years.
- The subject has a known or suspected hypercoagulable state.
Trial locations and contacts
92 sites in 9 countries.
92 sites in 9 countries
United States71 sites
Summa Health System
Akron, Ohio, 44304
Lehigh Valley Hospital
Allentown, Pennsylvania, 18103
Emory University Hospital
Atlanta, Georgia, 30308
Union Memorial Hospital
Baltimore, Maryland, 21218
Billings Clinic
Billings, Montana, 59101
Grandview Medical Center
Birmingham, Alabama, 35243
Aultman Hospital
Canton, Ohio, 44710
Carolinas Medical Center
Charlotte, North Carolina, 28203
University of Virginia Medical Center
Charlottesville, Virginia, 22908
Northwestern Memorial Hospital
Chicago, Illinois, 60611
Ohio State University Medical Center
Columbus, Ohio, 43210
OhioHealth Research and Innovation Institute - Riverside Methodist Hospital
Columbus, Ohio, 43214
Baylor Heart and Vascular Hospital
Dallas, Texas, 75226
Delray Medical Center
Delray Beach, Florida, 33484
Henry Ford Hospital
Detroit, Michigan, 48202
Evanston Hospital
Evanston, Illinois, 60201
Southcoast Physicians Group
Fall River, Massachusetts, 02720
Inova Fairfax Hospital
Falls Church, Virginia, 22042
North Colorado Medical Center
Greeley, Colorado, 80631
Cardiovascular Associates of the Delaware Valley
Haddon Heights, New Jersey, 08035
UPMC Heart and Vascular Institute Harrisburg
Harrisburg, Pennsylvania, 17043
Penn State Milton S Hershey Medical Center
Hershey, Pennsylvania, 17033
Huntsville Hospital
Huntsville, Alabama, 35801
St. Vincent's Hospital
Indianapolis, Indiana, 46290
Arrhythmia Research Group
Jonesboro, Arkansas, 72401
St. Luke's Hospital of Kansas City
Kansas City, Missouri, 64111
Scripps Memorial Hospital
La Jolla, California, 10666
Lakeland Regional Medical Center
Lakeland, Florida, 33805
St. Anthony Hospital
Lakewood, Colorado, 80228
Dartmouth Hitchcock Medical Center
Lebanon, New Hampshire, 03756
Baptist Health Lexington
Lexington, Kentucky, 40503
Cedars - Sinai Medical Center
Los Angeles, California, 90048
Catholic Medical Center
Manchester, New Hampshire, 03102
Aurora St. Luke's Medical Center
Milwaukee, Wisconsin, 53215
Froedtert Memorial Lutheran Hospital
Milwaukee, Wisconsin, 53215
Edward Hospital
Naperville, Illinois, 60540
Saint Thomas Health
Nashville, Tennessee, 37205
Mount Sinai Medical Center
New York, New York, 10029
St. Barnabas Medical Center
Newark, New Jersey, 07112
Heart Group at Deaconness Hospital
Newburgh, Indiana, 47630
Advocate Christ Medical Center
Oak Lawn, Illinois, 60453
The Nebraska Medical Center
Omaha, Nebraska, 68198
Kansas City Cardiac Arrhythmia Research
Overland Park, Kansas, 66211
Arizona Arrhythmia Research Center
Phoenix, Arizona, 85016
Maine Medical Center
Portland, Maine, 04074
Oregon Health Sciences University
Portland, Oregon, 97239
The Valley Hospital
Ridgewood, New Jersey, 07450
Carilion Roanoke Memorial Hospital
Roanoke, Virginia, 24014
Mayo Clinic Foundation
Rochester, Minnesota, 55905
Rochester General Hospital
Rochester, New York, 14621
Centracare Heart and Vascular
Saint Cloud, Minnesota, 56303
HealthEast St. Joseph's Hospital
Saint Paul, Minnesota, 55102
Sharpe Chula Vista Medical Center
San Diego, California, 92121
Santa Barbara Cottage Hospital
Santa Barbara, California, 93102
St. John's Health Center
Santa Monica, California, 90404
Sarasota Memorial Hospital
Sarasota, Florida, 34239
St. John's Hospital
Springfield, Illinois, 62769
Mercy Research
St Louis, Missouri, 63141
Northwell Health
Staten Island, New York, 10305
CHI Franciscan Health System
Tacoma, Washington, 98405
Tallahassee Memorial Hospital
Tallahassee, Florida, 32308
Bay Area Cardiology Associates
Tampa, Florida, 33511
Tampa General Hospital
Tampa, Florida, 33606
University of Texas Houston Health Science Center
The Woodlands, Texas, 77384
Oklahoma Heart Institute
Tulsa, Oklahoma, 74104
North Mississippi Medical Center
Tupelo, Mississippi, 38801
PeaceHealth Southwest Medical
Vancouver, Washington, 98664
Washington Hospital Center
Washington D.C., District of Columbia, 20010
Aspirus Heart and Vascular Institute - Research and Education
Wausau, Wisconsin, 54401
Mercy Hospital Medical Center
West Des Moines, Iowa, 50266
York Hospital
York, Pennsylvania, 17403
Germany5 sites
Universitaetsklinikum Dusseldorf
Düsseldorf
St.Johann Nepomuk Katholisches Hospitalvereinigung Thüringen GmbH
Erfurt
Cardioangiologisches Centrum Bethanien
Frankfurt
Cardiologicum Hamburg Praxis Wandsbek
Hamburg
Herzzentrum Universität Leipzig
Leipzig
United Kingdom5 sites
Royal Victoria Hospital
Belfast
Royal Sussex County Hospital
Brighton
Guys and St. Thomas NHS Foundation Trust
London
The Brompton Hospital
London
John Radcliffe Hospital
Oxford
Canada3 sites
Ottawa Heart Institute
Ottawa
Institut universitaire de Cardiologie et de Pneumologie de Quebec
Ste-foy
Vancouver General Hospital
Vancouver
Denmark2 sites
Aarhus University Hospital
Aarhus N, DK-8200
Rigshospitalet Copenhagen
Copenhagen, 2100
Netherlands2 sites
Medisch Spectrum Twente
Enschede
St. Antonius Ziekenhuis
Nieuwegein
About this study
Official title: Assessment of the WATCHMAN™ Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO)
The purpose of this study is to establish the safety and effectiveness of the WATCHMAN™ Left Atrial Appendage Closure (LAAC) Device, including the post-implant medication regimen, for subjects with non-valvular atrial fibrillation who are deemed not to be eligible for anti-coagulation therapy to reduce the risk of stroke.
Read the detailed description
The ASAP-TOO study is a prospective, randomized, multi-center, global investigation to establish the safety and effectiveness of the WATCHMAN Device for subjects with non-valvular atrial fibrillation who are deemed not suitable for anti-coagulation therapy to reduce the risk of stroke.
Subjects will be randomized in a ratio of 2 Device to 1 Control to receive the WATCHMAN LAA closure device (Device) or the control treatment of single antiplatelet medication or no medication at the discretion of the study physician (Control). All randomized subjects will follow the protocol required tests and assessments at each scheduled follow-up visit.
- Conditions
- Stroke
- Being tested
- WATCHMAN LAAC Device Implant, Single Antiplatelet Therapy or No Therapy (Control)
- Keywords
- Non-valvular atrial fibrillation, Left atrial appendage
- Medical subject headings
- Stroke
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
WATCHMAN LAAC Device ImplantDevice
WATCHMAN LAAC Implant
Single Antiplatelet Therapy or No Therapy (Control)Drug
Single Antiplatelet Therapy or No Therapy at the discretion of the study physician.
| Study group | Role | What they receive |
|---|---|---|
| WATCHMAN (Device) | Experimental | WATCHMAN LAAC Device implant including modified post-implant drug regimen. Receives: Device: WATCHMAN LAAC Device Implant |
| Control | Active comparator | Single antiplatelet therapy or no therapy (Control) at the discretion of the study physician for the duration of the trial. Receives: Drug: Single Antiplatelet Therapy or No Therapy (Control) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary 7-Day Device/Procedural Safety Endpoint
The primary safety endpoint is the 7-day combined rate of death, ischemic stroke, systemic embolism and complications requiring major cardiovascular or endovascular intervention measured only in the device arm, therefore the control is "0".
Measured: 7 days
Primary Efficacy Endpoint: Ischemic Stroke or Systemic Embolism.
Occurrence of ischemic stroke and systemic embolism adjudicated by and Independent Clinical Event Committee.
Measured: 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Oct 2016 (estimated)
- Study start6 Feb 2017
- Primary completion23 Sep 2025
- Study completion23 Sep 2025
Why it stopped: The enrollment was prematurely terminated on October 15, 2020, with 481 randomized patients. As discussed in the ASAP-TOO Update Meeting held on 16-September-2020 with FDA (Q150603-S001-A005), termination of enrollment was not due to safety concerns
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for StrokeStudies of the same condition, open and under way.
- More trials run by Boston Scientific CorporationThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 481 participants (actual)
Sponsor and investigators
- Lead sponsor
- Boston Scientific Corporation
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Jacqueline Saw, MD, Principal investigator, Vancouver General HospitalVivek Reddy, MD, Principal investigator, Icahn School of Medicine at Mount SinaiMaurice Buchbinder, MD, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02928497
- Sponsor's protocol ID
- S2317
- Acronym
- ASAP-TOO
- Status last verified
- Jun 2026
- First submitted
- 5 Oct 2016
- Last updated
- 25 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Publications
Alomar M, Fradley MG. Electrophysiology Translational Considerations in Cardio-Oncology: QT and Beyond. J Cardiovasc Transl Res. 2020 Jun;13(3):390-401. doi: 10.1007/s12265-019-09924-y. Epub 2019 Oct 31.
PubMed 31673900
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of the WATCHMAN™ Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO)
- ClinicalTrials.gov ID
- NCT02928497
- Acronym / sponsor ID
- ASAP-TOO / S2317
- Conditions
- Stroke
- Keywords
- Non-valvular atrial fibrillation, Left atrial appendage
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The enrollment was prematurely terminated on October 15, 2020, with 481 randomized patients. As discussed in the ASAP-TOO Update Meeting held on 16-September-2020 with FDA (Q150603-S001-A005), termination of enrollment was not due to safety concerns
- Enrolment
- 481 participants (actual)
- Lead sponsor
- Boston Scientific CorporationIndustry (pharma, biotech, devices)
- Study start
- 6 Feb 2017 (actual)
- Primary completion
- 23 Sep 2025 (actual)
- Study completion
- 23 Sep 2025 (actual)
- First posted
- 10 Oct 2016 (estimated)
- Results
- Posted 25 Aug 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to establish the safety and effectiveness of the WATCHMAN™ Left Atrial Appendage Closure (LAAC) Device, including the post-implant medication regimen, for subjects with non-valvular atrial fibrillation who are deemed not to be eligible for anti-coagulation therapy to reduce the risk of stroke.
Detailed description
The ASAP-TOO study is a prospective, randomized, multi-center, global investigation to establish the safety and effectiveness of the WATCHMAN Device for subjects with non-valvular atrial fibrillation who are deemed not suitable for anti-coagulation therapy to reduce the risk of stroke.
Subjects will be randomized in a ratio of 2 Device to 1 Control to receive the WATCHMAN LAA closure device (Device) or the control treatment of single antiplatelet medication or no medication at the discretion of the study physician (Control). All randomized subjects will follow the protocol required tests and assessments at each scheduled follow-up visit.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| WATCHMAN (Device) | Experimental | Device: WATCHMAN LAAC Device ImplantWATCHMAN LAAC Device implant including modified post-implant drug regimen. |
| Control | Active comparator | Drug: Single Antiplatelet Therapy or No Therapy (Control)Single antiplatelet therapy or no therapy (Control) at the discretion of the study physician for the duration of the trial. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- The subject is of legal age to participate in the study per the laws of their respective geography.
- The subject has documented paroxysmal, persistent, permanent or long-term/longstanding persistent non-valvular atrial fibrillation (i.e., the subject has not been diagnosed with rheumatic mitral valvular heart disease).
- The subject has a calculated CHA2DS2-VASc score of 2 or greater.
- The subject is deemed by two study physicians to be unsuitable for oral anticoagulation.
- The subject is deemed by a study physician to be suitable for the defined protocol pharmacologic regimen of aspirin and clopidogrel therapy following WATCHMAN Closure Device implant.
Key exclusion criteria (13 listed)
- The subject is unable or unwilling to return for required follow-up visits and examinations.
- The subject had or is planning to have any invasive cardiac procedure within 30 days prior to randomization (e.g., cardioversion, ablation).
- The subject is planning to have any cardiac or non-cardiac invasive or surgical procedure that would necessitate stopping or modifying the protocol required medication regimen within 90 days after the WATCHMAN Closure Device implant (e.g., cardioversion, ablation, cataract surgery).
- The subject had a prior stroke (of any cause) or TIA within the 30 days prior to randomization.
- The subject had a prior BARC type 3 or 4 bleeding event within the 14 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| WATCHMAN LAAC Device ImplantWATCHMAN LAAC Implant | Device | WATCHMAN (Device) |
| Single Antiplatelet Therapy or No Therapy (Control)Single Antiplatelet Therapy or No Therapy at the discretion of the study physician. | Drug | Control |
Primary outcome
Primary 7-Day Device/Procedural Safety Endpoint
Time frame: 7 days
The primary safety endpoint is the 7-day combined rate of death, ischemic stroke, systemic embolism and complications requiring major cardiovascular or endovascular intervention measured only in the device arm, therefore the control is "0".
Primary Efficacy Endpoint: Ischemic Stroke or Systemic Embolism.
Time frame: 5 years
Occurrence of ischemic stroke and systemic embolism adjudicated by and Independent Clinical Event Committee.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 31673900Alomar M, Fradley MG. Electrophysiology Translational Considerations in Cardio-Oncology: QT and Beyond. J Cardiovasc Transl Res. 2020 Jun;13(3):390-401. doi: 10.1007/s12265-019-09924-y. Epub 2019 Oct 31.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jacqueline Saw, MD principal investigator
Vancouver General Hospital
Vivek Reddy, MD principal investigator
Icahn School of Medicine at Mount Sinai
Maurice Buchbinder, MD principal investigator
Stanford University
92 sites in 9 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing WATCHMAN LAAC Device Implant in people with Stroke, run by Boston Scientific Corporation at 92 sites in 9 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 92 sites in United States, Germany, United Kingdom, Canada, Belgium and 4 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 25 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary 7-Day Device/Procedural Safety Endpoint (time frame: 7 days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02928497, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.