Tests a heart device that closes the left atrial appendage to prevent stroke
Tests a device closing a heart pouch in adults with atrial fibrillation.
Plain-language title generated from the registry record
Registry title: The Fourth Left Atrial Appendage Occlusion Study
Key facts
- Where
- Burlington, Calgary, Cambridge, Hamilton, Kitchener, London, Montreal, Newmarket, Ottawa, Québec, Regina, Saskatoon, Sherbrooke, St. Catharines, Toronto, Vancouver, and Winnipeg, CanadaSee the 24 sites
Where in Canada
- Circulate Cardiac & Vascular Centre (CCVC)Burlington, CanadaTaking people
- University Of CalgaryCalgary, CanadaTaking people
- Cambridge Cardiac Care Inc.Cambridge, CanadaTaking people
- Hamilton Health Sciences CorpHamilton, CanadaTaking people
- Research St. Joseph's - HamiltonHamilton, CanadaTaking people
- Waterloo Wellington Cardiovascular Research Institute (WWCRI)Kitchener, CanadaTaking people
- LAWSON Health Research InstituteLondon, CanadaTaking people
- Centre Hospitalier de l'Université de MontréalMontreal, CanadaTaking people
- Institut de Cardiologie de Montreal (ICM)Montreal, CanadaTaking people
- Partners in Advanced Cardiac Evaluation (PACE)Newmarket, CanadaTaking people
- Southlake Regional Health CentreNewmarket, CanadaTaking people
- Ottawa Heart Institute Research CorpOttawa, CanadaTaking people
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec-Université LavalQuébec, CanadaTaking people
- Prairie Valscular Research Inc. (PVRI)Regina, CanadaTaking people
- Saskatchewan Health AuthoritySaskatoon, CanadaTaking people
- Centre intégré universitaire de santé et de services sociaux de l'Estrie - Centre hospitalier universitaire de Sherbrooke (CIUSSS de l'Estrie-CHUS)Sherbrooke, CanadaTaking people
- Niagara Health Systems - St. CatharinesSt. Catharines, CanadaTaking people
- Niagara Health System - Niagara FallsSt. Catharines, CanadaNo longer taking part
- Lawrence Park CardiologyToronto, CanadaTaking people
- Sunnybrook Health Sciences CenterToronto, CanadaTaking people
- Unity Health TorontoToronto, CanadaTaking people
- University Health NetworkToronto, CanadaTaking people
- Vancouver Coastal Health AuthorityVancouver, CanadaTaking people
- St. Boniface Hospital Inc.Winnipeg, CanadaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Hamilton Health Sciences Corporation
- Trial code
- NCT05963698
- Record updated
- 18 September 2026
- Original description
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 full original descriptionShow less
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.
Inclusion: (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: 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; Individuals being treated with direct thrombin inhibitors; Age < 18 years; Anticipated life-expectancy of < 2 years; Current left atrial appendage thrombus; Planned atrial fibrillation ablation within 90 days of enrollment; Women of childbearing potential unless they agree to employ effective birth control methods throughout the study; Patient unable or willing to give informed consent.