The Conformal Prague Study

A prospective, single center, open-label, single arm, study to evaluate the safety and technical performance of the CLAAS system for closure of the left atrial appendage.

The primary objective of the study is to evaluate feasibility of ICE as primary imaging modality for device success in patients with non-valvular atrial fibrillation at increased risk for stroke and systemic embolism who are recommended for oral anticoagulation (OAC) therapy but have an appropriate rationale to seek a non-pharmacological alternative to OAC. TEE will be used to confirm the ICE evaluation.

Eligibility Criteria:
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 a CHA2DS2-VASc score of ≥ 2
4. The patient is recommended for oral anticoagulation therapy (OAC), but has an appropriate rationale to seek a non-pharmacologic alternative to chronic oral anticoagulation
5. The patient is willing and able to comply with the protocol-specified medication regimen and follow-up evaluations
6. The patient (or legally authorized representative) has been informed of the nature of the study, agrees to its provisions, and has provided written informed consent approved by the appropriate Ethics Committee (EC)

Exclusion Criteria:

1. Pregnant or nursing patients and those who plan pregnancy in the period up to 1 year following the index procedure. Female patients of childbearing potential must have a negative pregnancy test (per site standard test) within 7 days prior to index procedure.
2. Anatomic conditions that would prevent performance of an LAA occlusion procedure (e.g., prior atrial septal defect \[ASD\] or patent foramen ovale \[PFO\], surgical repair or implanted closure device, or obliterated or ligated left atrial appendage)
3. Atrial fibrillation that is defined by a single occurrence or that is transient or reversible (e.g., secondary thyroid disorders, acute alcohol intoxication, trauma, recent major surgical procedures)
4. Patients with a medical condition (other than atrial fibrillation) that mandates chronic oral anticoagulation (e.g., history of unprovoked deep vein thrombosis or pulmonary embolism, or mechanical heart valve)
5. History of bleeding diathesis or coagulopathy, or patients in whom antiplatelet and/or anticoagulant therapy is contraindicated
6. Active infection with bacteremia
7. Documented symptomatic carotid artery disease (\>50% diameter stenosis with prior ipsilateral stroke or TIA) or known asymptomatic carotid artery disease (diameter stenosis of \>70%)
8. Recent (within 30 days of index procedure) or planned (within 60 days post-procedure) cardiac or non-cardiac interventional or surgical procedure
9. Recent (within 90 days of index procedure) stroke, transient ischemic attack
10. Recent myocardial infarction within 60 days of index procedure
11. Vascular access precluding delivery of implant with catheter-based system
12. Severe heart failure (New York Heart Association Class III or IV)
13. Prior cardiac transplant, history of mitral valve replacement or transcatheter mitral valve intervention, or any mechanical valve implant
14. Renal insufficiency, defined as estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m2 (by the Modification of Diet in Renal Disease equation), or dialysis at the time of screening
15. Platelet count \<100,000 cells/mm3 or \>700,000 cells/mm3, or white blood cell count \<3,000 cells/mm3
16. Patient has a known allergy, hypersensitivity or contraindication to aspirin, heparin, clopidogrel, prasugrel, ticagrelor, or device materials (e.g., nickel, titanium, gold), or the patient has contrast sensitivity that cannot be adequately pre-medicated
17. Current participation in another investigational drug or device study that interferes with this study
18. Patient is a prisoner
19. Known other medical illness or known history of substance abuse that may cause non-compliance with the protocol or protocol-specified medication regimen, confound the data interpretation, or is associated with a life expectancy of less than 1 year
20. Patient has a condition which precludes adequate transesophageal echocardiographic (TEE) assessment