The CONFORM Pivotal Trial

Inclusion Criteria:

1. Male or non-pregnant female aged ≥18 years

2. Documented non-valvular AF (paroxysmal, persistent, or permanent)

3. High risk of stroke or systemic embolism, defined as CHA2DS2-VASc score of ≥ 3

4. Has an appropriate rationale to seek a non-pharmacologic alternative to long-termoral anticoagulation

5. Deemed by the site investigator to be suitable for short term oral anticoagulationtherapy but deemed less favorable for long-term oral anticoagulation therapy.

6. Deemed appropriate for LAA closure by the site investigator and a clinician not apart of the procedural team using a shared decision-making process in accordancewith standard of care

7. Able to comply with the protocol-specified medication regimen and follow-upevaluations

8. The subject (or legally authorized representative, where allowed) has been informedof the nature of the study, agrees to its provisions, and has provided writteninformed consent approved by the appropriate institutional review board (IRB)/Regional Ethics Board (REB)/Ethics Committee (EC).

Exclusion Criteria:

1. Pregnant or nursing patients and those who plan pregnancy in the period up to oneyear following the index procedure. Female patients of childbearing potential musthave a negative pregnancy test (per site standard test) within 7 days prior to indexprocedure.

2. Anatomic conditions that would prevent performance of an LAA occlusion procedure (e.g., atrial septal defect (ASD) requiring closure, high-risk patent foramen ovale (PFO) requiring closure, a highly mobile inter-atrial septal aneurysm precluding asafe TSP, presence of a PFO/ASD closure device, history of surgical ASD repair orhistory of surgical LAAO closure)

3. Atrial fibrillation that is defined by a single occurrence or that is transient orreversible (e.g., secondary thyroid disorders, acute alcohol intoxication, trauma,recent major surgical procedures)

4. A medical condition (other than atrial fibrillation) that mandates long-term oralanticoagulation (e.g., history of unprovoked deep vein thrombosis or pulmonaryembolism, or prosthetic mechanical heart valve)

5. History of bleeding diathesis or coagulopathy, or patients in whom antiplateletand/or anticoagulant therapy is contraindicated

6. Documented active systemic infection

7. Symptomatic carotid artery disease (defined as >50% stenosis with symptoms ofipsilateral transient or visual TIA evidenced by amaurosis fugax, ipsilateralhemispheric TIAs or ipsilateral stroke); if subject has a history of carotid stentor endarterectomy the subject is eligible if there is <50% stenosis noted at thesite of prior treatment

8. Recent (within 30 days of index procedure) or planned (within 60 dayspost-procedure) cardiac or major non-cardiac interventional or surgical procedure

9. Recent (within 30 days of index procedure) stroke or transient ischemic attack

10. Recent (within 30 days of index procedure) myocardial infarction

11. Vascular access precluding delivery of implant with catheter-based system

12. Severe heart failure (New York Heart Association Class IV)

13. Prior cardiac transplant, history of mitral valve replacement or transcathetermitral valve intervention, or any prosthetic mechanical valve implant

14. Renal insufficiency, defined as estimated glomerular filtration rate (eGFR) <30mL/min/1.73 m2 (by the Modification of Diet in Renal Disease equation)

15. Platelet count <75,000 cells/mm3 or >700,000 cells/mm3, or white blood cell count <3,000 cells/mm3

16. Known allergy, hypersensitivity or contraindication to aspirin, heparin, or devicematerials (e.g., nickel, titanium) that would preclude any P2Y12 inhibitor therapy,or the patient has contrast sensitivity that cannot be adequately pre-medicated

17. Actively enrolled or plans to enroll in a concurrent clinical study in which theactive treatment arm may confound the results of this trial

18. Unable to undergo general anesthesia

19. Known other medical illness or known history of substance abuse that may causenon-compliance with the protocol or protocol-specified medication regimen, confoundthe data interpretation, or is associated with a life expectancy of less than 5years

20. A condition which precludes adequate transesophageal echocardiographic assessment

Echo exclusion criteria:

1. Left atrial appendage anatomy which cannot accommodate a commercially availablecontrol device or the CLAAS Implant per manufacturer IFU (e.g., the anatomy andsizing must be appropriate for both the investigational (CLAAS) and a commerciallyavailable device in order to be enrolled in the trial)

2. Intracardiac thrombus or dense spontaneous echo contrast consistent with thrombus,as visualized by TEE prior to implant

3. Left ventricular ejection fraction (LVEF) <30%

4. Moderate or large circumferential pericardial effusion >10 mm or symptomaticpericardial effusion, signs or symptoms of acute or chronic pericarditis, orevidence of tamponade physiology

5. Atrial septal defect that warrants closure

6. High risk patent foramen ovale (PFO), defined as an atrial septal aneurysm (excursion >15 mm or length > 15 mm) or large shunt (early [within 3 beats] and/orsubstantial passage of bubbles, e.g., >20)

7. Moderate or severe mitral valve stenosis (mitral valve area <1.5 cm2)

8. Complex atheroma with mobile plaque of the descending aorta and/or aortic arch

9. Evidence of cardiac tumor