DEFLECT I: Keystone Heart Embolic Deflection Trial

Inclusion Criteria: 1. The patient must be ≥18 years of age. 2. Patient meets indications for TAVR procedure. 3. The patient is willing to comply with protocol-specified follow-up evaluations. 4. 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 Medical Ethics Committee or Institutional Review Board. Exclusion Criteria: 1. Patients undergoing TAVR via the trans-axillary, subclavian, or direct aortic route 2. Pregnant or nursing subjects and those who plan pregnancy in the period up to 1 year following index procedure. Female subjects of child-bearing potential must have a negative pregnancy test done within 7 days prior to index procedure per site standard test. 3. Patients with known diagnosis of acute myocardial infarction (AMI) within 72 hours preceding the index procedure (according to definition) or AMI \>72 hours preceding the index procedure, in whom creatine kinase and creatine kinase have not returned to within normal limits at the time of procedure. 4. Patients who are currently experiencing clinical symptoms consistent with new onset AMI, such as nitrate-unresponsive prolonged chest pain. 5. Patients with impaired renal function (estimated Glomerular Filtration Rate \[estimated Glomerular Filtration Rate\] \<30, calculated from serum creatinine by the Cockcroft-Gault formula) 6. Patients with a platelet count of \<100.000 cells/mm³ or \> 700.000 cells/mm³ or a white blood cell \< 3000 cells/mm³ within 7 days prior to index procedure. 7. Patients with a history of bleeding diathesis or coagulopathy or patients in whom anti-platelet and/or anticoagulant therapy is contraindicated, or who will refuse transfusion. 8. Patients who have received any organ transplant or are on a waiting list for any organ transplant. 9. Patients with known other medical illness or known history of substance abuse that may cause non-compliance with the protocol, confound the data interpretation or is associated with a life expectancy of less than one year. 10. Patients with known hypersensitivity or contraindication to aspirin, heparin/bivalirudin, clopidogrel/ticlopidine, nitinol, stainless steel alloy, and/or contrast sensitivity that cannot be adequately pre-medicated. 11. Patients with a history of a stroke or transient ischemic attack (TIA) within the prior 6 months. 12. Patients with an active peptic ulcer or history of upper gastrointestinal (GI) bleeding within the prior 6 months. 13. Patients presenting with cardiogenic shock. 14. Patients with severe peripheral arterial disease that precludes 9 French sheath vascular access. 15. Patients with documented friable or mobile atherosclerotic plaque in the aortic arch. 16. Patients with contraindication to cerebral MRI. 17. Patients who have a planned treatment with any other investigational device or procedure during the study period