AzTrials
AzTrials

Atrial FibrillationLAAOS-4NCT05963698

The Fourth Left Atrial Appendage Occlusion Study

A study testing WATCHMAN device in people with Atrial Fibrillation and Stroke, Ischemic, run by Hamilton Health Sciences Corporation at 150 sites in 12 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

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. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
WATCHMAN device
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
4,000 participants
Where
150 sitesin 12 countries
Study dates
30 Nov 2023to 1 Dec 2029
Phase
Interventional
Are there results?
Not yet: the study is under way

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

  • (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.

Who cannot join

  • 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
Show all 10Show fewer
  • 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

Trial locations and contacts

150 sites in 12 countries. Contact the study team or a site near you to ask about taking part.

Program Director contact

905-521-2100

LAAOS-4@phri.ca

150 sites in 12 countries

United States54 sites, 43 recruiting

  • Presbyterian Healthcare Services d.b.a. Presbyterian Heart Group

    Albuquerque, New Mexico, 87106

    Sharif Halim, MD

    Recruiting

  • University of Michigan

    Ann Arbor, Michigan, 48109

    Hakan Oral, MD

    Recruiting

  • Mission Hospital HCA

    Asheville, North Carolina, 28801

    John Rhyner, MD

    Recruiting

  • Emory University

    Atlanta, Georgia, 30322

    David De Lurgio, MD

    Recruiting

  • JFK Medical Center Limited Partnership d/b/a HCA Florida JFK Hospital

    Atlantis, Florida, 33462

    Withdrawn

  • Texas Cardiac Arrhythmia Research Foundation

    Austin, Texas, 78705

    Withdrawn

  • University of Maryland Baltimore

    Baltimore, Maryland, 21201

    Seemant Chaturvedi, MD

    Recruiting

  • Affinity Hospital dba Grandview Medical Center

    Birmingham, Alabama, 35243

    Withdrawn

  • St Luke's Regional Medical Center, Ltd

    Boise, Idaho, 83712

    Marcos Daccarett, MD

    Recruiting

  • Glanecare, Inc. d/b/a HCA Florida Brandon Hospital

    Brentwood, Tennessee, 37027

    Withdrawn

  • Lahey Clinic Inc.

    Burlington, Massachusetts, 01805

    Bruce Hook, MD

    Recruiting

  • Aultman Hospital

    Canton, Ohio, 44710

    Firas Hamdan, MD

    Recruiting

  • The Rector and Visitors of the University of Virginia

    Charlottesville, Virginia, 22903

    Rohit Malhotra, MD

    Recruiting

  • TriHealth Inc.

    Cincinnati, Ohio, 45202

    Gaurang Gandhi, MD

    Recruiting

  • University of Cincinnati

    Cincinnati, Ohio, 45221

    Srinivas Rajsheker, MD

    Recruiting

  • Cleveland Clinic

    Cleveland, Ohio, 44195

    Oussama Wazni, MD

    Recruiting

  • Kootenai Health Inc.

    Coeur d'Alene, Idaho, 83814

    Michele Murphy-Cook, MD

    Recruiting

  • Baylor Research Institute

    Dallas, Texas, 75204

    Praveen Rao, MD

    Recruiting

  • Henry Ford Health System

    Detroit, Michigan, 48202

    Waddah Maskoun, MD

    Recruiting

  • Henry Ford Health System

    Detroit, Michigan, 48202

    Amir Kaki, MD

    Recruiting

  • Northwestern University

    Evanston, Illinois, 60208

    Albert Lin, MD

    Recruiting

  • Memorial Health Services

    Fountain Valley, California, 92708

    Nikhil Warrier, MD

    Recruiting

  • Hackensack University Medical Center

    Hackensack, New Jersey, 07601

    Taya Glotzer, MD

    Recruiting

  • The Pennsylvania State University and The Milton S. Hershey Medical Center

    Hershey, Pennsylvania, 17033

    Soraya Samii, MD

    Recruiting

  • Community Health Network Inc.

    Indianapolis, Indiana, 46256

    Krishna Malineni, MD

    Recruiting

  • St. Vincent's Health System

    Jacksonville, Florida, 32204

    Withdrawn

  • Arrhythmia Research Group

    Jonesboro, Arkansas, 72401

    Devi Nair, MD

    Recruiting

  • University of Kansas Medical Center Research Institute, Inc.

    Kansas City, Kansas, 66160

    Madhu Reddy, MD

    Recruiting

  • Largo Medical Center, Inc. d/b/a HCA Florida Largo Medical Center

    Largo, Florida, 33770

    Withdrawn

  • Babtist Health Lexington

    Lexington, Kentucky, 40503

    Gery Tomassoni, MD

    Recruiting

  • Loma Linda University Health

    Loma Linda, California, 92354

    Withdrawn

  • Cedars-Sinai Medical Center

    Los Angeles, California, 90048

    Tarun Chakravarty, MD

    Recruiting

  • The Feinstein Institutes for Medical Research

    Manhasset, New York, 11030

    Withdrawn

  • The University of Tennessee

    Memphis, Tennessee, 38163

    Balaji Krishnaiah, MD

    Recruiting

  • The Medical College of Wisconsin

    Milwaukee, Wisconsin, 53226

    James Oujiri, MD

    Recruiting

  • Ochsner Clinic Foundation

    New Orleans, Louisiana, 70121

    Richard Zweifler, MD

    Recruiting

  • Cornell University for and on behalf of its Joan & Sanford I. Weill Medical College and The New York Presbyterian Hospital

    New York, New York, 10065

    Christopher Liu, MD

    Recruiting

  • NYU Grossman School of Medicine

    New York, New York, 10065

    Withdrawn

  • HCA Florida Ocala Hospital

    Ocala, Florida, 34471

    Withdrawn

  • Southern California Permanente Medical Group

    Pasadena, California, 91101

    Bahram Khadivi, MD

    Recruiting

  • The Trustees of the University of Pennsylvania

    Philadelphia, Pennsylvania, 19104

    Steven Messe, MD

    Recruiting

  • University of Pittsburgh Medical Center (UPMC) Presbyterian Heart and Vascular Institute

    Pittsburgh, Pennsylvania, 15213

    Sandeep Jain, MD

    Recruiting

  • Rhode Island Hospital

    Providence, Rhode Island, 02903

    Ana-Lucia Garcia-Guarniz, MD

    Recruiting

  • Mayo Clinic

    Rochester, Minnesota, 55905

    Eugene L. Scharf, MD

    Recruiting

  • Cardiovascular Medicine, PLLC and Unity Point Trinity Rock Island

    Rock Island, Illinois, 61201

    Mark Shen, MD

    Recruiting

  • Sutter Valley Hospitals dba Sutter Institute for Medical Research

    Sacramento, California, 95816

    David Roberts, MD

    Recruiting

  • St. Louis University,

    St Louis, Missouri, 63103

    Div Verma, MD

    Recruiting

  • CommonSpirit Health Research Institute

    Tacoma, Washington, 98405

    Nasir Shariff, MD

    Recruiting

  • The University of South Florida

    Tampa, Florida, 33620

    Bibhu Mohanty, MD

    Recruiting

  • Heart Rhythm Associates

    The Woodlands, Texas, 77380

    Withdrawn

  • Saint Francis Hospital

    Tulsa, Oklahoma, 74136

    Tom Hu, MD

    Recruiting

  • CHRISTUS Northeast Texas Health System

    Tyler, Texas, 75701-2263

    Stanislav Weiner, MD

    Recruiting

  • MercyOne Iowa Heart Center

    West Des Moines, Iowa, 50266

    Pitayadet Jumrussirikul, MD

    Recruiting

  • Christiana Care Health Services, Inc.

    Wilmington, Delaware, 19803

    Neil Wimmer, MD

    Recruiting

Other trials in United States

Canada24 sites, 23 recruiting

  • Circulate Cardiac & Vascular Centre (CCVC)

    Burlington, Ontario, L7M 1K9

    Hisham Dokainish, MD

    Recruiting

  • University of Calgary

    Calgary, Alberta, T2N 1N4

    Stephen Wilton, MD

    Recruiting

  • Cambridge Cardiac Care Inc.

    Cambridge, Ontario, N1R 6V6

    A. Shekhar Pandey, MD

    Recruiting

  • Hamilton Health Sciences Corp

    Hamilton, Ontario, L8L 2X2

    Guy Amit, MD

    Recruiting

  • Research St. Joseph's - Hamilton

    Hamilton, Ontario, L8N 4A6

    Vikas Tandon, MD

    Recruiting

  • Waterloo Wellington Cardiovascular Research Institute (WWCRI)

    Kitchener, Ontario, N2M 5N6

    Umjeet Jolly, MD

    Recruiting

  • Lawson Health Research Institute

    London, Ontario, N6A 2R5

    Allan Skanes, MD

    Recruiting

  • Institut de Cardiologie de Montreal (ICM)

    Montreal, Quebec, H1T 1C8

    Reda Ibrahim, MD

    Recruiting

  • Centre hospitalier de l'Université de Montréal

    Montreal, Quebec, H2X OC1

    Jean-Marc Raymond, MD

    Recruiting

  • Southlake Regional Health Centre

    Newmarket, Ontario, L2Y 2P9

    Mouhannad Sadek, MD

    Recruiting

  • Partners in Advanced Cardiac Evaluation (PACE)

    Newmarket, Ontario, L3Y 2P6

    Yaariv Khaykin, MD

    Recruiting

  • Ottawa Heart Institute Research Corp

    Ottawa, Ontario, K1Y 4W7

    Omar Abdel-Razek, MD

    Recruiting

  • Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval

    Québec, Quebec, G1V 4G5

    Jean Champagne, MD

    Recruiting

  • Prairie Valscular Research Inc. (PVRI)

    Regina, Saskatchewan, S4P 0W5

    Payam Dehghani, MD

    Recruiting

  • Saskatchewan Health Authority

    Saskatoon, Saskatchewan, S7K 0M7

    Stephan Wardell, MD

    Recruiting

  • Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie - CHUS)

    Sherbrooke, Quebec, J1J 3H5

    Charles Dussault, MD

    Recruiting

  • Niagara Health System - Niagara Falls

    St. Catharines, Ontario, L2S 0A9

    Withdrawn

  • Niagara Health Systems - St. Catharines

    St. Catharines, Ontario, L2S 0A9

    Nigel Tan, MD

    Recruiting

  • Sunnybrook Health Sciences Center

    Toronto, Ontario, M4N 3M5

    Sheldon Singh, MD

    Recruiting

  • Lawrence Park Cardiology

    Toronto, Ontario, M4N 3N1

    Eugene Crystal, MD

    Recruiting

  • Unity Health Toronto

    Toronto, Ontario, M5B 1W8

    Neil Fam, MD

    Recruiting

  • University Health Network

    Toronto, Ontario, M5G 2C4

    Eric Horlick, MD

    Recruiting

  • Vancouver Coastal Health Authority

    Vancouver, British Columbia, V5Z 1M9

    Jason Andrade, MD

    Recruiting

  • St. Boniface Hospital Inc.

    Winnipeg, Manitoba, R2H 2A6

    Malek Kass, MD

    Recruiting

Other trials in Canada

Germany19 sites, 19 recruiting

  • Krankenhausbetriebsgesellschaft Bad Oeynhausen mbH

    Bad Oeynhausen, North Rhine-Westphalia, 32545

    Werner Scholtz, MD

    Recruiting

  • Charité Universitätsmedizin Berlin

    Berlin, 10117

    Leif-Hendrik Boldt, MD

    Recruiting

  • Charité - Universitätsmedizin Berlin

    Berlin, 12203

    Carsten Skurk, MD

    Recruiting

  • Universitätsklinikum Köln (AöR)

    Cologne, North Rhine-Westphalia, 50937

    Daniel Steven, Prof., MD

    Recruiting

  • Kardiovaskulaeres Zentrum Darmstadt

    Darmstadt, Hesse, 64287

    Jörg Honold, MD

    Recruiting

  • Katholisches Krankenhaus "St. Johann Nepomuk"

    Erfurt, Thuringia, 99097

    Henning Ebelt, MD

    Recruiting

  • CVC Rhein-Main GmbH

    Frankfurt am Main, Hesse, 60389

    Horst Sievert, MD

    Recruiting

  • MVZ CCB Frankfurt und Main-Taunus GbR

    Frankfurt am Main, Hesse, 60431

    Boris Schmidt, MD

    Recruiting

  • Johann Wolfgang Goethe Universität Franfurt - Universitätsklinikum Franfurt

    Frankfurt am Main, Hesse, 60590

    Reza Wakili, MD

    Recruiting

  • Asklepios Kliniken Hamburg GmbH

    Hamburg, 20099

    Arian Sultan, MD

    Recruiting

  • Asklepios Kliniken Hamburg GmbH

    Hamburg, 20099

    Martin Bergmann, MD

    Recruiting

  • Universitätsklinikum Hamburg-Eppendorf (UKE)

    Hamburg, 20246

    Andreas Metzner, Prof., MD

    Recruiting

  • Universitätsklinikum Heidelberg

    Heidelberg, 69120

    Farbod Sedaghat-Hamedani, MD

    Recruiting

  • Westpfalz-Klinikum GmbH

    Kaiserslautern, Rhineland-Palatinate, 67665

    Burghard Schumacher, MD

    Recruiting

  • Städtisches Klinikum Karsruhe gGmbH

    Karlsruhe, Baden-Wurttemberg, 76133

    Armin Luik, Prof., MD

    Recruiting

  • Herzzentrum Leipzig GmbH

    Leipzig, Saxony, 04289

    Marcus Sandri, MD

    Recruiting

  • Universitätsklinikum Schleswig - Holstein

    Lübeck, Schleswig-Holstein, 23538

    Ingo Eitel, MD

    Recruiting

  • Universitätsmedizin Rostock

    Rostock, Mecklenburg-Vorpommern, D-18057

    Hueseyin Ince, Prof., MD

    Recruiting

  • Heinrich-Braun-Klinikum gemeinnützige GmbH

    Zwickau, Saxony, 08060

    Holger H. Sigusch, MD

    Recruiting

Other trials in Germany

France18 sites, 18 recruiting

  • CHR Metz-Thionville / Hôpital de MERCY

    Ars-Laquenexy, Moselle

    Marwan Yassine, MD

    Recruiting

  • Infirmerie Protestante de Lyon

    Caluire-et-Cuire, Rhône, 69300

    Cyril Durand, MD

    Recruiting

  • Centre Hospitalier Universitaire Grenoble-Alps

    La Tronche, Isère, 38700

    Pascal Defaye, Prof., MD

    Recruiting

  • Hospices Civils de Lyon

    Lyon, 69677

    Brahim Harbaoui, Prof., MD

    Recruiting

  • L'Assistance Publique-Hôpitaux de Marseille

    Marseille, Rhône, 13005

    Thomas Cuisset, MD

    Recruiting

  • Hôpital Privé Clairval

    Marseille, Rhône, 13009

    Alexis Mechulan, MD

    Recruiting

  • Hospital Prive Jacques Cartier

    Massy, Essonne, 91300

    Phillipe Garot, MD

    Recruiting

  • The Fondation de l'AP-HP

    Paris, 75012

    Emmanuel Teiger, Prof., MD

    Recruiting

  • Hôpital Pitie Salpétrière

    Paris, 75013

    Johanne Silvain, Prof., MD

    Recruiting

  • Institut Médico-chirurgical Montsouris

    Paris, 75014

    Alaa Masri, MD

    Recruiting

  • Hôpital Bichat

    Paris, 75018

    Gregory Ducrocq, Prof., MD

    Recruiting

  • European Georges Pompidou Hospital

    Paris, 75908

    Eloi Marijon, MD

    Recruiting

  • Centre Cardiologique due Nord

    Saint-Denis, Seine-Saint-Denis, 93200

    Antoine Lepillier, MD

    Recruiting

  • CHU Saint Etienne

    Saint-Étienne-de-Montluc, Pays de la Loire Region, 42055

    Antoine Da Costa, Prof., MD

    Recruiting

  • Centre Hospitalier Universitaire de Toulouse

    Toulouse, Occitanie, 31059

    Meyer Elbaz, Prof., MD

    Recruiting

  • Clinique Pasteur

    Toulouse, Occitanie, 31076

    Serge Boveda, MD

    Recruiting

  • SCP des Médecins Cardiologues

    Toulouse, Occitanie, 31076

    Bruno Farah, MD

    Recruiting

  • Centre Hospitalier Régional Universitaire de Tours

    Tours, Indre-et-Loire, 37044

    Jean Michel Clerc, MD

    Recruiting

Other trials in France

Belgium8 sites, 8 recruiting

  • AZORG vzw and Hartcentrum Aalst

    Aalst, East-Flanders, 9300

    Tom De Potter, MD

    Recruiting

  • Imeldaziekenhuis

    Bonheiden, Antwerpen, 2820

    Philippe Debruyne, MD

    Recruiting

  • AZ Sint Jan Brugge AV

    Bruges, West-Vlaanderen, 8000

    Ian Buysschaert, MD

    Recruiting

  • Universitair Ziekenhuis Brussel

    Brussels, 1090

    Stijn Lochy, MD

    Recruiting

  • ASBL CHU Helora - Hôpital de La Louvière - site Jolimont

    La Louvière, Hainaut, 7100

    Antoine de Meester, MD

    Recruiting

  • CHR de la Citadelle

    Liège, 4000

    Jean-Manuel Herzet, MD

    Recruiting

  • AZ Delta VZW

    Roeselare, West-Vlaanderen, 8800

    Maarten Vanhaverbeke, MD

    Recruiting

  • AZ Glorieux

    Ronse, Oost-Vlaanderen, 9600

    Becker Alzand, MD

    Recruiting

Other trials in Belgium

Spain7 sites, 7 recruiting

  • University General Hospital Dr. Balmis

    Alicante, 03010

    Juan Miguel Ruiz Nodar, MD

    Recruiting

  • Hospital Universitari Vall d'Hebron

    Barcelona, 08035

    Jaume Francisco Pascual, MD

    Recruiting

  • Hospital Universitario Juan Ramón Jiménez

    Huelva, 21005

    Antonio Enrique Gómez Menchero, MD

    Recruiting

  • Complejo Asistencial Universitario de León

    León, 24071

    Armando Perez de Prado, MD

    Recruiting

  • Universitario La Luz - Grupo Quirónsalud

    Madrid, 28003

    Jorge Palazuelos, MD

    Recruiting

  • Hospital Clínico Universitario de Valladolid

    Valladolid, 47003

    Ignacio Amat Santos, MD

    Recruiting

  • Hospital Álvaro Cunqueiro

    Vigo, Pontevedra, 36312

    Rodrigo Estevez Loureiro, MD

    Recruiting

Other trials in Spain

United Kingdom7 sites, 7 recruiting

  • University Hospitals Coventry and Warwickshire

    Coventry, West Midlands, CV2 2DX

    Sandeep Panikker, MD

    Recruiting

  • University Hospitals of Leicester NHS Trust

    Leicester, Leicestershire, LE1 5WW

    Jan Kovac, Prof., MD

    Recruiting

  • Liverpool Heart and Chest Hospital NHS Foundation Trust

    Liverpool, L14 3PE

    Dhiraj Gupta, MD

    Recruiting

  • Nottingham University Hospital NHS Trust

    Nottingham, Nottinghamshire, NG5 1PB

    Ashan Gunarathne, MD

    Recruiting

  • Oxford University Hospitals NHS Foundation Trust

    Oxford, Oxfordshire, OX3 9DU

    Tim Betts, MD

    Recruiting

  • University Hospital Southampton NHS Foundation Trust

    Southampton, SO16 6YD

    John Paisey, MD

    Recruiting

  • University Hospitals Sussex NHS Trust

    Worthing, West Sussex, BN11 2DH

    David Hildick-Smith, MD

    Recruiting

Other trials in United Kingdom

Denmark6 sites, 6 recruiting

  • Aarhus University Hospital (AUH)

    Aarhus, Region Midt, 8200

    Jens Erik Nielsen-Kudsk, MD

    Recruiting

  • Rigshospitalet (RH)

    Copenhagen, 2100

    Ole De Backer, MD

    Recruiting

  • Esbjerg & Grindsted Hospital - University Hospital of Southern Denmark

    Esbjerg, Region Syddanmark, 6700

    Axel Brandes, MD

    Recruiting

  • North Denmark Regional Hospital

    Hjørring, 9800

    Albert Marni Joensen, MD

    Recruiting

  • Odense Universitets Hospital

    Odense C, 4500

    Mikkel Hougaard, MD

    Recruiting

  • Region Hospital Viborg

    Viborg, Central Jutland, 8800

    Andi Eie Albertsen, MD

    Recruiting

Other trials in Denmark

Italy2 sites, 2 recruiting

  • Fondazione Poliambulanza Istituto Ospedaliero

    Brescia, 25124

    Diego Maffeo, MD

    Recruiting

  • Azienda Ospedaliero Universitaria Sassari

    Sassari, 07100

    Gavino Casu, Prof., MD

    Recruiting

Other trials in Italy

Netherlands2 sites, 2 recruiting

  • Stichting Catharina Ziekenhuis

    Eindhoven, North Brabant, 5623EJ

    Pepijn van der Voort, MD

    Recruiting

  • St. Antonius Hospital

    Nieuwegein, Utrecht, 3435CM

    Lucas Boersma, Prof., MD

    Recruiting

Other trials in Netherlands

Poland2 sites, 2 recruiting

  • American Heart of Poland SA

    Ustroń, 43-450

    Krzysztof Milewski, MD

    Recruiting

  • Narodowy Instytut Kardiologii Stefana kardynała Wyszyńskiego

    Warsaw, Masovian Voivodeship, 04-628

    Jerzy Pregowski, MD

    Recruiting

Other trials in Poland

Switzerland1 site, 1 recruiting

  • Universitätsspital Basel

    Basel, Canton of Basel-City, 4031

    Christian Sticherling, Prof., MD

    Recruiting

Other trials in Switzerland

About this study

Official title: 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.

Read the 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.

Being tested
WATCHMAN device
Keywords
WATCHMAN, Left Atrial Appendage (LAA), LAA Device, Left Atrial Appendage Occlusion
Medical subject headings
Atrial Fibrillation, Ischemic Stroke

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • WATCHMAN deviceDevice

    Participants will undergo endovascular left atrial appendage occlusion with the WATCHMAN device

Study groups in NCT05963698
Study groupRoleWhat they receive
WATCHMAN deviceExperimentalParticipants will undergo endovascular left atrial appendage occlusion with the WATCHMAN device
Receives: Device: WATCHMAN device
Standard CareNo interventionParticipants will receive local, standard medical care

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Ischemic stroke or systemic embolism

    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

    Measured: 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 outcomes (6)

  1. All-cause stroke or systemic embolism

    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

    Measured: 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).

  2. All-cause stroke, systemic embolism, or transient ischemic attack (TIA)

    Time from randomization to first occurrence of all-cause stroke, systemic embolism or transient ischemic attack (TIA)

    Measured: 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).

  3. Montreal Cognitive Assessment (MoCA) Score

    Proportion of participants with a decrease of two or more points on the MoCA score at either year 2 or end of study

    Measured: 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).

  4. New disabling ischemic strokes

    Time from randomization to first occurrence of disabling ischemic strokes with modified Rankin Score (mRS) >2, measured at 90 days post-stroke

    Measured: 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).

  5. Cardiovascular mortality

    Time from randomization to cardiovascular mortality

    Measured: 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).

  6. All-cause mortality

    Time from randomization to all-cause mortality

    Measured: 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).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted27 Jul 2023
  2. Study start30 Nov 2023
  3. Primary completion1 Sep 2029 (estimated)
  4. Study completion1 Dec 2029 (estimated)

Resources

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
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Randomized Controlled Trial
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
4,000 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05963698
Sponsor's protocol ID
LAAOS-4
Acronym
LAAOS-4
Status last verified
Jun 2026
First submitted
5 Jul 2023
Last updated
18 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

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.

    PubMed 39344366

Questions about this trial

What is this clinical trial studying?

A study testing WATCHMAN device in people with Atrial Fibrillation and Stroke, Ischemic, run by Hamilton Health Sciences Corporation at 150 sites in 12 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 3 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 18 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 150 sites in United States, Canada, Germany, France, Belgium and 7 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Program Director (905-521-2100, LAAOS-4@phri.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

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).). 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 NCT05963698, 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 18 Sep 2026.

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