The Fourth Left Atrial Appendage Occlusion Study (LAAOS-4)

June 4, 2026 updated by: Hamilton Health Sciences Corporation

The Fourth Left Atrial Appendage Occlusion Study (LAAOS-4)

LAAOS-4 aims to determine if catheter-based endovascular left atrial appendage occlusion prevents ischemic stroke or systemic embolism in participants with atrial fibrillation, who remain at high risk of stroke, despite receiving ongoing treatment with oral anticoagulation.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Device: WATCHMAN device

Detailed Description

LAAOS-4 is a multicentre, prospective, open-label, randomized controlled trial with blinded assessment of endpoints (PROBE) to determine if catheter-based endovascular left atrial appendage occlusion prevents ischemic stroke or systemic embolism in participants with atrial fibrillation, who remain at high risk of stroke, despite receiving ongoing treatment with oral anticoagulation.

Study Type

Interventional

Enrollment (Estimated)

4000

Phase

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

Name: Program Director
Phone Number: 905-521-2100
Email: LAAOS-4@phri.ca

Study Locations

Belgium
- - Brussels, Belgium, 1090
    - Recruiting
    - Universitair Ziekenhuis Brussel
    - Principal Investigator:
      
      Stijn Lochy, MD
- Antwerpen
  - Bonheiden, Antwerpen, Belgium, 2820
    - Recruiting
    - Imeldaziekenhuis
    - Principal Investigator:
      
      Philippe Debruyne, MD
- East-Flanders
  - Aalst, East-Flanders, Belgium, 9300
    - Recruiting
    - AZORG vzw and Hartcentrum Aalst
    - Principal Investigator:
      
      Tom De Potter, MD
- Hainaut
  - La Louvière, Hainaut, Belgium, 7100
    - Recruiting
    - ASBL CHU Helora - Hôpital de La Louvière - site Jolimont
    - Principal Investigator:
      
      Antoine de Meester, MD
- Liège
  - Liège, Liège, Belgium, 4000
    - Recruiting
    - CHR de la Citadelle
    - Principal Investigator:
      
      Jean-Manuel Herzet, MD
- Oost-Vlaanderen
  - Ronse, Oost-Vlaanderen, Belgium, 9600
    - Recruiting
    - AZ Glorieux
    - Principal Investigator:
      
      Becker Alzand, MD
- West-Vlaanderen
  - Bruges, West-Vlaanderen, Belgium, 8000
    - Recruiting
    - AZ Sint Jan Brugge AV
    - Principal Investigator:
      
      Ian Buysschaert, MD
  - Roeselare, West-Vlaanderen, Belgium, 8800
    - Recruiting
    - AZ Delta vzw
    - Principal Investigator:
      
      Maarten Vanhaverbeke, MD
Canada
- Alberta
  - Calgary, Alberta, Canada, T2N 1N4
    - Recruiting
    - University of Calgary
    - Principal Investigator:
      
      Stephen Wilton, MD
- British Columbia
  - Vancouver, British Columbia, Canada, V5Z 1M9
    - Recruiting
    - Vancouver Coastal Health Authority
    - Principal Investigator:
      
      Jason Andrade, MD
- Manitoba
  - Winnipeg, Manitoba, Canada, R2H 2A6
    - Recruiting
    - St. Boniface Hospital Inc.
    - Principal Investigator:
      
      Malek Kass, MD
- Ontario
  - Burlington, Ontario, Canada, L7M 1K9
    - Recruiting
    - Circulate Cardiac & Vascular Centre (CCVC)
    - Principal Investigator:
      
      Hisham Dokainish, MD
  - Cambridge, Ontario, Canada, N1R 6V6
    - Recruiting
    - Cambridge Cardiac Care Inc.
    - Principal Investigator:
      
      A. Shekhar Pandey, MD
  - Hamilton, Ontario, Canada, L8N 4A6
    - Recruiting
    - Research St. Joseph's - Hamilton
    - Principal Investigator:
      
      Vikas Tandon, MD
  - Hamilton, Ontario, Canada, L8L 2X2
    - Recruiting
    - Hamilton Health Sciences Corp
    - Principal Investigator:
      
      Guy Amit, MD
  - Kitchener, Ontario, Canada, N2M 5N6
    - Recruiting
    - Waterloo Wellington Cardiovascular Research Institute (WWCRI)
    - Principal Investigator:
      
      Umjeet Jolly, MD
  - London, Ontario, Canada, N6A 2R5
    - Recruiting
    - Lawson Health Research Institute
    - Principal Investigator:
      
      Allan Skanes, MD
  - Newmarket, Ontario, Canada, L2Y 2P9
    - Recruiting
    - Southlake Regional Health Centre
    - Principal Investigator:
      
      Mouhannad Sadek, MD
  - Newmarket, Ontario, Canada, L3Y 2P6
    - Recruiting
    - Partners in Advanced Cardiac Evaluation (PACE)
    - Principal Investigator:
      
      Yaariv Khaykin, MD
  - Ottawa, Ontario, Canada, K1Y 4W7
    - Recruiting
    - Ottawa Heart Institute Research Corp
    - Principal Investigator:
      
      Omar Abdel-Razek, MD
  - St. Catharines, Ontario, Canada, L2S 0A9
    - Recruiting
    - Niagara Health System - Niagara Falls
    - Principal Investigator:
      
      Danielle de Sa Boasquevisque, MD
  - St. Catharines, Ontario, Canada, L2S 0A9
    - Recruiting
    - Niagara Health Systems - St. Catharines
    - Principal Investigator:
      
      Nigel Tan, MD
  - Toronto, Ontario, Canada, M5G 2C4
    - Recruiting
    - University Health Network
    - Principal Investigator:
      
      Eric Horlick, MD
  - Toronto, Ontario, Canada, M4N 3M5
    - Recruiting
    - Sunnybrook Health Sciences Center
    - Principal Investigator:
      
      Sheldon Singh, MD
  - Toronto, Ontario, Canada, M5B 1W8
    - Recruiting
    - Unity Health Toronto
    - Principal Investigator:
      
      Neil Fam, MD
  - Toronto, Ontario, Canada, M4N 3N1
    - Recruiting
    - Lawrence Park Cardiology
    - Principal Investigator:
      
      Eugene Crystal, MD
- Quebec
  - Montreal, Quebec, Canada, H1T 1C8
    - Recruiting
    - Institut de Cardiologie de Montreal (ICM)
    - Principal Investigator:
      
      Reda Ibrahim, MD
  - Montreal, Quebec, Canada, H2X OC1
    - Recruiting
    - Centre Hospitalier de l'Université de Montréal
    - Principal Investigator:
      
      Jean-Marc Raymond, MD
  - Québec, Quebec, Canada, G1V 4G5
    - Recruiting
    - Institut Universitaire de Cardiologie et de Pneumologie de Québec-Université Laval
    - Principal Investigator:
      
      Jean Champagne, MD
  - Sherbrooke, Quebec, Canada, J1J 3H5
    - Recruiting
    - Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS)
    - Principal Investigator:
      
      Charles Dussault, MD
- Saskatchewan
  - Regina, Saskatchewan, Canada, S4P 0W5
    - Recruiting
    - Prairie Valscular Research Inc. (PVRI)
    - Principal Investigator:
      
      Payam Dehghani, MD
  - Saskatoon, Saskatchewan, Canada, S7K 0M7
    - Recruiting
    - Saskatchewan Health Authority
    - Principal Investigator:
      
      Stephan Wardell, MD
Denmark
- - Copenhagen, Denmark, 2100
    - Recruiting
    - Rigshospitalet (RH)
    - Principal Investigator:
      
      Ole De Backer, MD
  - Hjørring, Denmark, 9800
    - Recruiting
    - North Denmark Regional Hospital
    - Principal Investigator:
      
      Albert Marni Joensen, MD
  - Odense C, Denmark, 4500
    - Recruiting
    - Odense Universitets Hospital
    - Principal Investigator:
      
      Mikkel Hougaard, MD
- Central Jutland
  - Viborg, Central Jutland, Denmark, 8800
    - Recruiting
    - Region Hospital Viborg
    - Principal Investigator:
      
      Andi Eie Albertsen, MD
- Region Midt
  - Aarhus, Region Midt, Denmark, 8200
    - Recruiting
    - Aarhus University Hospital (AUH)
    - Principal Investigator:
      
      Jens Erik Nielsen-Kudsk, MD
- Region Syddanmark
  - Esbjerg, Region Syddanmark, Denmark, 6700
    - Recruiting
    - Esbjerg & Grindsted Hospital - University Hospital of Southern Denmark
    - Principal Investigator:
      
      Axel Brandes, MD
France
- - Paris, France, 75013
    - Recruiting
    - Hôpital Pitié Salpêtrière
    - Principal Investigator:
      
      Johanne Silvain, Prof., MD
  - Paris, France, 75018
    - Recruiting
    - Hôpital Bichat
    - Principal Investigator:
      
      Gregory Ducrocq, Prof., MD
  - Paris, France, 75908
    - Recruiting
    - European Georges Pompidou Hospital
    - Principal Investigator:
      
      Eloi Marijon, MD
  - Paris, France, 75014
    - Recruiting
    - Institut Médico-chirurgical Montsouris
    - Principal Investigator:
      
      Alaa Masri, MD
- Auvergne-Rhône-Alpes
  - Caluire-et-Cuire, Auvergne-Rhône-Alpes, France, 69300
    - Recruiting
    - Infirmerie Protestante de Lyon
    - Principal Investigator:
      
      Cyril Durand, MD
  - Saint-Etienne, Auvergne-Rhône-Alpes, France, 42055
    - Recruiting
    - CHU Saint Etienne
    - Principal Investigator:
      
      Antoine Da Costa, Prof., MD
- Centre-Val de Loire
  - Tours, Centre-Val de Loire, France, 37044
    - Recruiting
    - Centre Hospitalier Regional Universitaire De Tours
    - Principal Investigator:
      
      Jean Michel Clerc, MD
- Moselle
  - Ars-Laquenexy, Moselle, France
    - Recruiting
    - CHR Metz-Thionville / Hôpital de Mercy
    - Principal Investigator:
      
      Marwan Yassine, MD
- Occitanie
  - Toulouse, Occitanie, France, 31076
    - Recruiting
    - Clinique Pasteur
    - Principal Investigator:
      
      Serge Boveda, MD
  - Toulouse, Occitanie, France, 31076
    - Recruiting
    - SCP des Médecins Cardiologues
    - Principal Investigator:
      
      Bruno Farah, MD
  - Toulouse, Occitanie, France, 31059
    - Recruiting
    - Centre Hospitalier Universitaire de Toulouse
    - Principal Investigator:
      
      Meyer Elbaz, Prof., MD
- Paris
  - Paris, Paris, France, 75012
    - Recruiting
    - The Fondation de l'AP-HP
    - Principal Investigator:
      
      Emmanuel Teiger, Prof., MD
- Provence-Alpes-Côte d'Azur Region
  - Marseille, Provence-Alpes-Côte d'Azur Region, France, 13005
    - Recruiting
    - L'Assistance Publique-Hôpitaux de Marseille
    - Principal Investigator:
      
      Thomas Cuisset, MD
- Île-de-France Region
  - Massy, Île-de-France Region, France, 91300
    - Recruiting
    - Hospital Prive Jacques Cartier
    - Principal Investigator:
      
      Phillipe Garot, MD
  - Saint-Denis, Île-de-France Region, France, 93200
    - Recruiting
    - Centre Cardiologique due Nord
    - Principal Investigator:
      
      Antoine Lepillier, MD
Germany
- - Berlin, Germany, 12203
    - Recruiting
    - Charite - Universitätsmedizin Berlin
    - Principal Investigator:
      
      Carsten Skurk, MD
  - Berlin, Germany, 10117
    - Recruiting
    - Charité Universitätsmedizin Berlin
    - Principal Investigator:
      
      Leif-Hendrik Boldt, MD
  - Hamburg, Germany, 20246
    - Recruiting
    - Universitätsklinikum Hamburg-Eppendorf (UKE)
    - Principal Investigator:
      
      Andreas Metzner, Prof., MD
  - Hamburg, Germany, 20099
    - Recruiting
    - Asklepios Kliniken Hamburg GmbH
    - Principal Investigator:
      
      Martin Bergmann, MD
  - Heidelberg, Germany, 69120
    - Recruiting
    - Universitätsklinikum Heidelberg
    - Principal Investigator:
      
      Farbod Sedaghat-Hamedani, MD
- Baden-Wurttemberg
  - Karlsruhe, Baden-Wurttemberg, Germany, 76133
    - Recruiting
    - Städtisches Klinikum Karsruhe gGmbH
    - Principal Investigator:
      
      Armin Luik, Prof., MD
- Hesse
  - Darmstadt, Hesse, Germany, 64287
    - Recruiting
    - Kardiovaskulaeres Zentrum Darmstadt
    - Principal Investigator:
      
      Jörg Honold, MD
  - Frankfurt am Main, Hesse, Germany, 60389
    - Recruiting
    - CVC Rhein-Main GmbH
    - Principal Investigator:
      
      Horst Sievert, MD
  - Frankfurt am Main, Hesse, Germany, 60431
    - Recruiting
    - MVZ CCB Frankfurt und Main-Taunus GbR
    - Principal Investigator:
      
      Boris Schmidt, MD
  - Frankfurt am Main, Hesse, Germany, 60590
    - Recruiting
    - Johann Wolfgang Goethe Universität Franfurt - Universitätsklinikum Franfurt
    - Principal Investigator:
      
      Reza Wakili, MD
- Mecklenburg-Vorpommern
  - Rostock, Mecklenburg-Vorpommern, Germany, D-18057
    - Recruiting
    - Universitatsmedizin Rostock
    - Principal Investigator:
      
      Hueseyin Ince, Prof., MD
- North Rhine-Westphalia
  - Bad Oeynhausen, North Rhine-Westphalia, Germany, 32545
    - Recruiting
    - Krankenhausbetriebsgesellschaft Bad Oeynhausen mbH
    - Principal Investigator:
      
      Werner Scholtz, MD
- Rhineland-Palatinate
  - Kaiserslautern, Rhineland-Palatinate, Germany, 67665
    - Recruiting
    - Westpfalz-Klinikum GmbH
    - Principal Investigator:
      
      Burghard Schumacher, MD
- Saxony
  - Leipzig, Saxony, Germany, 04289
    - Recruiting
    - Herzzentrum Leipzig GmbH
    - Principal Investigator:
      
      Marcus Sandri, MD
  - Zwickau, Saxony, Germany, 08060
    - Recruiting
    - Heinrich-Braun-Klinikum gemeinnützige GmbH
    - Principal Investigator:
      
      Holger H. Sigusch, MD
- Schleswig-Holstein
  - Lübeck, Schleswig-Holstein, Germany, 23538
    - Recruiting
    - Universitätsklinikum Schleswig - Holstein
    - Principal Investigator:
      
      Ingo Eitel, MD
- Thuringia
  - Erfurt, Thuringia, Germany, 99097
    - Recruiting
    - Katholisches Krankenhaus "St. Johann Nepomuk"
    - Principal Investigator:
      
      Henning Ebelt, MD
Italy
- - Brescia, Italy, 25124
    - Recruiting
    - Fondazione Poliambulanza Istituto Ospedaliero
    - Principal Investigator:
      
      Diego Maffeo, MD
- Sassari
  - Sassari, Sassari, Italy, 07100
    - Recruiting
    - Azienda Ospedaliero Universitaria Sassari
    - Principal Investigator:
      
      Gavino Casu, Prof., MD
Netherlands
- North Brabant
  - Eindhoven, North Brabant, Netherlands, 5623EJ
    - Recruiting
    - Stichting Catharina Ziekenhuis
    - Principal Investigator:
      
      Pepijn van der Voort, MD
Poland
- - Ustroń, Poland, 43-450
    - Recruiting
    - American Heart of Poland SA
    - Principal Investigator:
      
      Krzysztof Milewski, MD
- Masovian Voivodeship
  - Warsaw, Masovian Voivodeship, Poland, 04-628
    - Recruiting
    - Narodowy Instytut Kardiologii Stefana kardynała Wyszyńskiego
    - Principal Investigator:
      
      Jerzy Pregowski, MD
Spain
- - Alicante, Spain, 03010
    - Recruiting
    - University General Hospital Dr. Balmis
    - Principal Investigator:
      
      Juan Miguel Ruiz Nodar, MD
  - León, Spain, 24071
    - Recruiting
    - Complejo asistencial universitario de Leon
    - Principal Investigator:
      
      Armando Perez de Prado, MD
  - Madrid, Spain, 28003
    - Recruiting
    - Universitario La Luz - Grupo Quirónsalud
    - Principal Investigator:
      
      Jorge Palazuelos, MD
  - Valladolid, Spain, 47003
    - Recruiting
    - Hospital Clinico Universitario de Valladolid
    - Principal Investigator:
      
      Ignacio Amat Santos, MD
- Pontevedra
  - Vigo, Pontevedra, Spain, 36312
    - Recruiting
    - Hospital Álvaro Cunqueiro
    - Principal Investigator:
      
      Rodrigo Estevez Loureiro, MD
Switzerland
- Canton of Basel-City
  - Basel, Canton of Basel-City, Switzerland, 4031
    - Recruiting
    - Universitätsspital Basel
    - Principal Investigator:
      
      Christian Sticherling, Prof., MD
United Kingdom
- - Liverpool, United Kingdom, L14 3PE
    - Recruiting
    - Liverpool Heart and Chest Hospital NHS Foundation Trust
    - Principal Investigator:
      
      Dhiraj Gupta, MD
  - Southampton, United Kingdom, SO16 6YD
    - Recruiting
    - University Hospital Southampton NHS Foundation Trust
    - Principal Investigator:
      
      John Paisey, MD
- Leicestershire
  - Leicester, Leicestershire, United Kingdom, LE1 5WW
    - Recruiting
    - University Hospitals of Leicester NHS Trust
    - Principal Investigator:
      
      Jan Kovac, Prof., MD
- Nottinghamshire
  - Nottingham, Nottinghamshire, United Kingdom, NG5 1PB
    - Recruiting
    - Nottingham University Hospital NHS Trust
    - Principal Investigator:
      
      Ashan Gunarathne, MD
- Oxfordshire
  - Oxford, Oxfordshire, United Kingdom, OX3 9DU
    - Recruiting
    - Oxford University Hospitals NHS Foundation Trust
    - Principal Investigator:
      
      Tim Betts, MD
- West Midlands
  - Coventry, West Midlands, United Kingdom, CV2 2DX
    - Recruiting
    - University Hospitals Coventry and Warwickshire
    - Principal Investigator:
      
      Sandeep Panikker, MD
- West Sussex
  - Worthing, West Sussex, United Kingdom, BN11 2DH
    - Recruiting
    - University Hospitals Sussex NHS Trust
    - Principal Investigator:
      
      David Hildick-Smith, MD
United States
- Alabama
  - Birmingham, Alabama, United States, 35243
    - Withdrawn
    - Affinity Hospital dba Grandview Medical Center
- Arkansas
  - Jonesboro, Arkansas, United States, 72401
    - Recruiting
    - Arrhythmia Research Group
    - Principal Investigator:
      
      Devi Nair, MD
- California
  - Fountain Valley, California, United States, 92708
    - Recruiting
    - Memorial Health Services
    - Principal Investigator:
      
      Nikhil Warrier, MD
  - Loma Linda, California, United States, 92354
    - Recruiting
    - Loma Linda University Health
    - Principal Investigator:
      
      Rahul Bhardwaj, MD
  - Pasadena, California, United States, 91101
    - Recruiting
    - Southern California Permanente Medical Group
    - Principal Investigator:
      
      Bahram Khadivi, MD
  - Sacramento, California, United States, 95816
    - Recruiting
    - Sutter Valley Hospitals dba Sutter Institute for Medical Research
    - Principal Investigator:
      
      David Roberts, MD
- Florida
  - Atlantis, Florida, United States, 33462
    - Recruiting
    - JFK Medical Center Limited Partnership d/b/a HCA Florida JFK Hospital
    - Principal Investigator:
      
      Marcelo Jimenez, MD
  - Jacksonville, Florida, United States, 32204
    - Recruiting
    - St. Vincent's Health System
    - Principal Investigator:
      
      Saumil Oza, MD
  - Largo, Florida, United States, 33770
    - Recruiting
    - Largo Medical Center, Inc. d/b/a HCA Florida Largo Medical Center
    - Principal Investigator:
      
      Jesse Klein, MD
  - Ocala, Florida, United States, 34471
    - Recruiting
    - HCA Florida Ocala Hospital
    - Principal Investigator:
      
      Gregory Von Mering, MD
  - Tampa, Florida, United States, 33620
    - Recruiting
    - The University of South Florida
    - Principal Investigator:
      
      Bibhu Mohanty, MD
- Georgia
  - Atlanta, Georgia, United States, 30322
    - Recruiting
    - Emory University
    - Principal Investigator:
      
      David De Lurgio, MD
- Idaho
  - Boise, Idaho, United States, 83712
    - Recruiting
    - St Luke's Regional Medical Center, Ltd
    - Principal Investigator:
      
      Marcos Daccarett, MD
  - Coeur d'Alene, Idaho, United States, 83814
    - Recruiting
    - Kootenai Health Inc.
    - Principal Investigator:
      
      Michele Murphy-Cook, MD
- Illinois
  - Evanston, Illinois, United States, 60208
    - Recruiting
    - Northwestern University
    - Principal Investigator:
      
      Albert Lin, MD
  - Rock Island, Illinois, United States, 61201
    - Recruiting
    - Cardiovascular Medicine, PLLC and Unity Point Trinity Rock Island
    - Principal Investigator:
      
      Mark Shen, MD
- Indiana
  - Indianapolis, Indiana, United States, 46256
    - Recruiting
    - Community Health Network Inc.
    - Principal Investigator:
      
      Krishna Malineni, MD
- Iowa
  - West Des Moines, Iowa, United States, 50266
    - Recruiting
    - MercyOne Iowa Heart Center
    - Principal Investigator:
      
      Pitayadet Jumrussirikul, MD
- Kansas
  - Kansas City, Kansas, United States, 66160
    - Recruiting
    - University of Kansas Medical Center Research Institute, Inc.
    - Principal Investigator:
      
      Madhu Reddy, MD
- Kentucky
  - Lexington, Kentucky, United States, 40503
    - Recruiting
    - Babtist Health Lexington
    - Principal Investigator:
      
      Gery Tomassoni, MD
- Louisiana
  - New Orleans, Louisiana, United States, 70121
    - Recruiting
    - Ochsner Clinic Foundation
    - Principal Investigator:
      
      Richard Zweifler, MD
- Maryland
  - Baltimore, Maryland, United States, 21201
    - Recruiting
    - University of Maryland Baltimore
    - Principal Investigator:
      
      Seemant Chaturvedi, MD
- Massachusetts
  - Burlington, Massachusetts, United States, 01805
    - Recruiting
    - Lahey Clinic Inc.
    - Principal Investigator:
      
      Bruce Hook, MD
- Michigan
  - Ann Arbor, Michigan, United States, 48109
    - Recruiting
    - University of Michigan
    - Principal Investigator:
      
      Hakan Oral, MD
  - Detroit, Michigan, United States, 48202
    - Recruiting
    - Henry Ford Health System
    - Principal Investigator:
      
      Amir Kaki, MD
- Minnesota
  - Rochester, Minnesota, United States, 55905
    - Recruiting
    - Mayo Clinic
    - Principal Investigator:
      
      Eugene L. Scharf, MD
- New Jersey
  - Hackensack, New Jersey, United States, 07601
    - Recruiting
    - Hackensack University Medical Center
    - Principal Investigator:
      
      Taya Glotzer, MD
- New Mexico
  - Albuquerque, New Mexico, United States, 87106
    - Recruiting
    - Presbyterian Healthcare Services d.b.a. Presbyterian Heart Group
    - Principal Investigator:
      
      Sharif Halim, MD
- New York
  - Manhasset, New York, United States, 11030
    - Recruiting
    - The Feinstein Institutes for Medical Research
    - Principal Investigator:
      
      Jeffrey Katz, MD
  - New York, New York, United States, 10065
    - Recruiting
    - Cornell University for and on behalf of its Joan & Sanford I. Weill Medical College and The New York Presbyterian Hospital
    - Principal Investigator:
      
      Christopher Liu, MD
  - New York, New York, United States, 10065
    - Withdrawn
    - NYU Grossman School of Medicine
- North Carolina
  - Asheville, North Carolina, United States, 28801
    - Recruiting
    - Mission Hospital HCA
    - Principal Investigator:
      
      John Rhyner, MD
- Ohio
  - Canton, Ohio, United States, 44710
    - Recruiting
    - Aultman Hospital
    - Principal Investigator:
      
      Firas Hamdan, MD
  - Cincinnati, Ohio, United States, 45221
    - Recruiting
    - University of Cincinnati
    - Principal Investigator:
      
      Srinivas Rajsheker, MD
  - Cincinnati, Ohio, United States, 45202
    - Recruiting
    - TriHealth Inc.
    - Principal Investigator:
      
      Gaurang Gandhi, MD
  - Cleveland, Ohio, United States, 44195
    - Recruiting
    - Cleveland Clinic
    - Principal Investigator:
      
      Oussama Wazni, MD
- Oklahoma
  - Tulsa, Oklahoma, United States, 74136
    - Recruiting
    - Saint Francis Hospital
    - Principal Investigator:
      
      Tom Hu, MD
- Pennsylvania
  - Hershey, Pennsylvania, United States, 17033
    - Recruiting
    - The Pennsylvania State University and The Milton S. Hershey Medical Center
    - Principal Investigator:
      
      Soraya Samii, MD
  - Philadelphia, Pennsylvania, United States, 19104
    - Recruiting
    - The Trustees of the University of Pennsylvania
    - Principal Investigator:
      
      Steven Messe, MD
  - Pittsburgh, Pennsylvania, United States, 15213
    - Recruiting
    - University of Pittsburgh Medical Center (UPMC) Presbyterian Heart and Vascular Institute
    - Principal Investigator:
      
      Sandeep Jain, MD
- Rhode Island
  - Providence, Rhode Island, United States, 02903
    - Recruiting
    - Rhode Island Hospital
    - Principal Investigator:
      
      Ana-Lucia Garcia-Guarniz, MD
- Tennessee
  - Brentwood, Tennessee, United States, 37027
    - Recruiting
    - Glanecare, Inc. d/b/a HCA Florida Brandon Hospital
    - Principal Investigator:
      
      Umesh Gowda, MD
  - Memphis, Tennessee, United States, 38163
    - Recruiting
    - The University of Tennessee
    - Principal Investigator:
      
      Balaji Krishnaiah, MD
- Texas
  - Austin, Texas, United States, 78705
    - Withdrawn
    - Texas Cardiac Arrhythmia Research Foundation
  - Dallas, Texas, United States, 75204
    - Recruiting
    - Baylor Research Institute
    - Principal Investigator:
      
      Praveen Rao, MD
  - The Woodlands, Texas, United States, 77380
    - Withdrawn
    - Heart Rhythm Associates
  - Tyler, Texas, United States, 75701-2263
    - Recruiting
    - CHRISTUS Northeast Texas Health System
    - Principal Investigator:
      
      Stanislav Weiner, MD
- Virginia
  - Charlottesville, Virginia, United States, 22903
    - Recruiting
    - The Rector and Visitors of the University of Virginia
    - Principal Investigator:
      
      Rohit Malhotra, MD
- Washington
  - Tacoma, Washington, United States, 98405
    - Recruiting
    - CommonSpirit Health Research Institute
    - Principal Investigator:
      
      Nasir Shariff, MD
- Wisconsin
  - Milwaukee, Wisconsin, United States, 53226
    - Recruiting
    - The Medical College of Wisconsin
    - Principal Investigator:
      
      James Oujiri, MD

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

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Description

Inclusion Criteria:

(a) Persistent or permanent atrial fibrillation OR (b) Paroxysmal atrial fibrillation in participants with a history of ischemic stroke or systemic embolism
Increased risk of stroke, defined as a CHA2DS2-VASc stroke risk score of ≥ 4. [Note: the acronym CHA2DS2-VASc stands for congestive heart failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled), vascular disease, age 65 to 74 and sex category (female).]
Treatment with oral anticoagulants (Vitamin K agonist or factor Xa inhibitor) for at least 90 days prior to enrollment, AND no documented plan to discontinue treatment with oral anticoagulants for the expected duration of the trial.

Exclusion Criteria:

Age < 18 years
Current left atrial appendage thrombus
Prior left atrial appendage occlusion or removal (surgical or percutaneous)
Prior percutaneous atrial septal defect or patent foramen ovale closure
Prior atrial fibrillation ablation unless evidence of recurrent qualifying atrial fibrillation present at least 30 days following ablation
Planned atrial fibrillation ablation within 90 days of enrollment
Individuals being treated with direct thrombin inhibitors
Women of childbearing potential unless they agree to employ effective birth control methods throughout the study
Anticipated life-expectancy of < 2 years
Patient unable or willing to give informed consent

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: Treatment
Allocation: Randomized
Interventional Model: Parallel Assignment
Masking: Single

Number of Arms

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: WATCHMAN device Participants will undergo endovascular left atrial appendage occlusion with the WATCHMAN device	Device: WATCHMAN device Participants will undergo endovascular left atrial appendage occlusion with the WATCHMAN device
No Intervention: Standard Care Participants will receive local, standard medical care

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ischemic stroke or systemic embolism Time Frame: The study duration is event-driven. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	The primary efficacy variable is the time from randomization to first occurrence of any of the components of the composite outcome (adjudicated) over the duration of follow-up, including: Ischemic stroke (Strokes of undetermined etiology will be treated as ischemic stroke) Systemic embolism	The study duration is event-driven. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
All-cause stroke or systemic embolism Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Secondary efficacy outcomes will be evaluated in a hierarchical fashion only when the primary outcome meets statistical significance in the specified order: Time from randomization to first occurrence of all-cause stroke or systemic embolism	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
All-cause stroke, systemic embolism, or transient ischemic attack (TIA) Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to first occurrence of all-cause stroke, systemic embolism or transient ischemic attack (TIA)	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Montreal Cognitive Assessment (MoCA) Score Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Proportion of participants with a decrease of two or more points on the MoCA score at either year 2 or end of study	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
New disabling ischemic strokes Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to first occurrence of disabling ischemic strokes with modified Rankin Score (mRS) >2, measured at 90 days post-stroke	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Cardiovascular mortality Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to cardiovascular mortality	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
All-cause mortality Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to all-cause mortality	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Non-procedural Major Bleeding Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Proportion of participants with non-procedural Major Bleeding (International Society on Thrombosis and Haemostasis (ISTH) definition; excluding WATCHMAN-related bleeding within 14 days of implant)	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Hospitalization for any cause Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to first occurrence of hospitalization for any cause	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Heart failure hospitalization or emergency department/clinic visit for intensification of heart failure related therapy Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to first occurrence of heart failure hospitalization or emergency department/clinic visit for intensification of heart failure related therapy	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Myocardial Infarction Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Time from randomization to first occurrence of Myocardial Infarction (4th Universal definition)	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Device and procedural-related outcomes: Device-related thrombus Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Proportion of participants with device-related thrombus (thrombus formed on the surface of the WATCHMAN device)	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Device and procedural-related outcomes: Incomplete left atrial appendage (LAA) closure Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Proportion of participants with incomplete LAA closure	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).
Device and procedural-related outcomes: Peri-procedural major bleeding Time Frame: Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).	Proportion of participants with peri-procedural major bleeding (ISTH definition; within 14 days following the procedure)	Will be evaluated once primary outcome meets statistical significance. The primary analysis will be performed through study completion, once 265 primary efficacy endpoint events have occurred (an estimated average follow-up of 4 years).

Collaborators and Investigators

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

Sponsor

Hamilton Health Sciences Corporation

Collaborators

McMaster University

Boston Scientific Corporation

Population Health Research Institute

Investigators

Principal Investigator: Jeff Healey, Hamilton Health Sciences Corporation

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Grifoni E, Pagni B, Sansone T, Baldini M, Bertini E, Giannoni S, Di Donato I, Sivieri I, Iandoli G, Mannini M, Giglio E, Vescera V, Brai E, Signorini I, Cosentino E, Micheletti I, Cioni E, Pelagalli G, Dei A, Giordano A, Dainelli F, Romagnoli M, Mattaliano C, Schipani E, Murgida GS, Di Martino S, Francolini V, Masotti L. Clinical Features, Management, and Recurrence of Acute Ischemic Stroke Occurring in Patients on Oral Anticoagulant Treatment for Nonvalvular Atrial Fibrillation: A Real-World Retrospective Study. Neurologist. 2024 Nov 1;29(6):329-338. doi: 10.1097/NRL.0000000000000579.

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)

November 30, 2023

Primary Completion (Estimated)

September 1, 2029

Study Completion (Estimated)

December 1, 2029

Study Registration Dates

First Submitted

July 5, 2023

First Submitted That Met QC Criteria

July 18, 2023

First Posted (Actual)

July 27, 2023

Study Record Updates

Last Update Posted (Actual)

June 8, 2026

Last Update Submitted That Met QC Criteria

June 4, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

LAAOS-4

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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