ASAP-TOO: Assessment of the WATCHMAN™ Device in Patients Unsuitable for Oral Anticoagulation

Boston Scientific Corporation (Industry)
Overall Status
Active, not recruiting ID
Anticipated Duration (Months)
Patients Per Site
Patients Per Site Per Month

Study Details

Study Description

Brief 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 stroke.

Condition or DiseaseIntervention/TreatmentPhase
  • Device: WATCHMAN LAAC Device Implant
  • Drug: Single Antiplatelet Therapy or No Therapy (Control)

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

Study Type:
Actual Enrollment :
481 participants
Intervention Model:
Parallel Assignment
None (Open Label)
Primary Purpose:
Official Title:
Assessment of the WATCHMAN™ Device in Patients Unsuitable for Oral Anticoagulation (ASAP-TOO)
Actual Study Start Date :
Feb 15, 2017
Anticipated Primary Completion Date :
Dec 1, 2025
Anticipated Study Completion Date :
Dec 1, 2025

Arms and Interventions

Experimental: WATCHMAN (Device)

WATCHMAN LAAC Device implant including modified post-implant drug regimen.

Device: WATCHMAN LAAC Device Implant

Active Comparator: Control

Single antiplatelet therapy or no therapy (Control) at the discretion of the study physician for the duration of the trial.

Drug: Single Antiplatelet Therapy or No Therapy (Control)
Single Antiplatelet Therapy or No Therapy at the discretion of the study physician.

Outcome Measures

Primary Outcome Measures

  1. Primary 7-Day Device/Procedural Safety Endpoint [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.

  2. Primary Efficacy Endpoint - time to first event of ischemic stroke or systemic embolism. [5 years]

    The primary efficacy endpoint is the comparison of time to first event of ischemic stroke and systemic embolism.

Secondary Outcome Measures

  1. Secondary Endpoint - Composite of All Stroke and Cardiovascular or Unknown Death [5 years]

    The occurrence of stroke (including ischemic and/or hemorrhagic), cardiovascular death (cardiovascular and/or unexplained cause) and systemic embolism

  2. Secondary Endpoint - Major Bleeding [5 years]

    The occurrence of major bleeding (defined as a BARC Type 3 or 5 event)

Eligibility Criteria


Ages Eligible for Study:
18 Years and Older
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Inclusion Criteria:
  • 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.

Exclusion Criteria:
  • 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.

  • 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.

Contacts and Locations


SiteCityStateCountryPostal Code
1Grandview Medical CenterBirminghamAlabamaUnited States35243
2Huntsville HospitalHuntsvilleAlabamaUnited States35801
3Arizona Arrhythmia Research CenterPhoenixArizonaUnited States85016
4Arrhythmia Research GroupJonesboroArkansasUnited States72401
5Scripps Memorial HospitalLa JollaCaliforniaUnited States10666
6Cedars - Sinai Medical CenterLos AngelesCaliforniaUnited States90048
7Sharpe Chula Vista Medical CenterSan DiegoCaliforniaUnited States92121
8Santa Barbara Cottage HospitalSanta BarbaraCaliforniaUnited States93102
9St. John's Health CenterSanta MonicaCaliforniaUnited States90404
10North Colorado Medical CenterGreeleyColoradoUnited States80631
11St. Anthony HospitalLakewoodColoradoUnited States80228
12Washington Hospital CenterWashingtonDistrict of ColumbiaUnited States20010
13Delray Medical CenterDelray BeachFloridaUnited States33484
14Lakeland Regional Medical CenterLakelandFloridaUnited States33805
15Sarasota Memorial HospitalSarasotaFloridaUnited States34239
16Tallahassee Memorial HospitalTallahasseeFloridaUnited States32308
17Bay Area Cardiology AssociatesTampaFloridaUnited States33511
18Tampa General HospitalTampaFloridaUnited States33606
19Emory University HospitalAtlantaGeorgiaUnited States30308
20Northwestern Memorial HospitalChicagoIllinoisUnited States60611
21NorthShore University Health SystemEvanstonIllinoisUnited States60201
22Edward HospitalNapervilleIllinoisUnited States60540
23Advocate Christ Medical CenterOak LawnIllinoisUnited States60453
24St. John's HospitalSpringfieldIllinoisUnited States62769
25St. Vincent's HospitalIndianapolisIndianaUnited States46290
26Heart Group at Deaconness HospitalNewburghIndianaUnited States47630
27Mercy Hospital Medical CenterWest Des MoinesIowaUnited States50266
28Kansas City Cardiac Arrhythmia ResearchOverland ParkKansasUnited States66211
29Baptist Health LexingtonLexingtonKentuckyUnited States40503
30Maine Medical CenterPortlandMaineUnited States04074
31Union Memorial HospitalBaltimoreMarylandUnited States21218
32Soutcoast Physicians GroupFall RiverMassachusettsUnited States02720
33Henry Ford HospitalDetroitMichiganUnited States48202
34Mayo Clinic FoundationRochesterMinnesotaUnited States55905
35Centracare Heart and VascularSaint CloudMinnesotaUnited States56303
36HealthEast St. Joseph's HospitalSaint PaulMinnesotaUnited States55102
37North Mississippi Medical CenterTupeloMississippiUnited States38801
38St. Luke's Hospital of Kansas CityKansas CityMissouriUnited States64111
39Mercy ResearchSaint LouisMissouriUnited States63141
40Billings ClinicBillingsMontanaUnited States59101
41The Nebraska Medical CenterOmahaNebraskaUnited States68198
42Dartmouth Hitchcock Medical CenterLebanonNew HampshireUnited States03756
43Catholic Medical CenterManchesterNew HampshireUnited States03102
44Cardiovascular Associates of the Delaware ValleyHaddon HeightsNew JerseyUnited States08035
45St. Barnabas Medical CenterNewarkNew JerseyUnited States07112
46The Valley HospitalRidgewoodNew JerseyUnited States07450
47Mount Sinai Medical CenterNew YorkNew YorkUnited States10029
48Rochester General HospitalRochesterNew YorkUnited States14621
49Northwell HealthStaten IslandNew YorkUnited States10305
50Carolinas Medical CenterCharlotteNorth CarolinaUnited States28203
51Summa Health SystemAkronOhioUnited States44304
52Aultman HospitalCantonOhioUnited States44710
53Ohio State University Medical CenterColumbusOhioUnited States43210
54OhioHealth Research and Innovation Institute - Riverside Methodist HospitalColumbusOhioUnited States43214
55Oklahoma Heart InstituteTulsaOklahomaUnited States74104
56Oregon Health Sciences UniversityPortlandOregonUnited States97239
57Lehigh Valley HospitalAllentownPennsylvaniaUnited States18103
58Pinnacle Health at Harrisburg HospitalHarrisburgPennsylvaniaUnited States17043
59Penn State Milton S Hershey Medical CenterHersheyPennsylvaniaUnited States17033
60York HospitalYorkPennsylvaniaUnited States17403
61Saint Thomas HealthNashvilleTennesseeUnited States37205
62Baylor Heart and Vascular HospitalDallasTexasUnited States75226
63University of Texas Houston Health Science CenterThe WoodlandsTexasUnited States77384
64University of Virginia Medical CenterCharlottesvilleVirginiaUnited States22908
65Inova Fairfax HospitalFalls ChurchVirginiaUnited States22042
66Carilion Roanoke Memorial HospitalRoanokeVirginiaUnited States24014
67CHI Franciscan Health SystemTacomaWashingtonUnited States98405
68PeaceHealth Southwest MedicalVancouverWashingtonUnited States98664
69Aurora St. Luke's Medical CenterMilwaukeeWisconsinUnited States53215
70Froedtert Memorial Lutheran HospitalMilwaukeeWisconsinUnited States53215
71Aspirus Heart and Vascular Institute - Research and EducationWausauWisconsinUnited States54401
72Onze Lieve Vrouw ZiekenhuisAalstBelgium9300
73ZNA MiddelheimAntwerpBelgium
74Ottawa Heart InstituteOttawaCanada
75Institut universitaire de Cardiologie et de Pneumologie de QuebecSte-foyCanada
76Vancouver General HospitalVancouverCanada
77Na Homolce HospitalPragueCzechia150 30
78Skejby SygehusAarhus NDenmarkDK-8200
79Rigshospitalet CopenhagenCopenhagenDenmark2100
80Universitaetsklinikum DusseldorfDusseldorfGermany
81St.Johann Nepomuk Katholisches Hospitalvereinigung Thüringen GmbHErfurtGermany
82Cardioangiologisches Centrum BethanienFrankfurtGermany
83Cardiologicum Hamburg Praxis WandsbekHamburgGermany
84Herzzentrum Universität LeipzigLeipzigGermany
85Fondazione Toscana Gabriele MonasterioMassaItaly
86Medisch Spectrum TwenteEnschedeNetherlands
87St. Antonius ZiekenhuisNieuwegeinNetherlands
88Royal Victoria HospitalBelfastUnited Kingdom
89Royal Sussex County HospitalBrightonUnited Kingdom
90Guys and St. Thomas NHS Foundation TrustLondonUnited Kingdom
91The Brompton HospitalLondonUnited Kingdom
92John Radcliffe HospitalOxfordUnited Kingdom

Sponsors and Collaborators

  • Boston Scientific Corporation


  • Principal Investigator: Jacqueline Saw, MD, Vancouver General Hospital
  • Principal Investigator: Vivek Reddy, MD, Icahn School of Medicine at Mount Sinai
  • Principal Investigator: Maurice Buchbinder, MD, Stanford University

Study Documents (Full-Text)

None provided.

More Information


None provided.
Responsible Party:
Boston Scientific Corporation Identifier:
Other Study ID Numbers:
  • S2317
First Posted:
Oct 10, 2016
Last Update Posted:
Nov 19, 2021
Last Verified:
Nov 1, 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD:
Studies a U.S. FDA-regulated Drug Product:
Studies a U.S. FDA-regulated Device Product:
Keywords provided by Boston Scientific Corporation

Study Results

No Results Posted as of Nov 19, 2021