DEFLECT III: A Prospective, Randomized Evaluation of the TriGuard™ HDH Embolic Deflection Device During TAVI

Inclusion Criteria: * The patient is a male or non-pregnant female ≥18 years of age * Patient meets indications for TAVI * The patient is willing to comply with protocol-specified follow-up evaluations * 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 (EC) or Institutional Review Board (IRB) Exclusion Criteria: * Patients undergoing TAVI via the trans-axillary, trans-subclavian, or trans-aortic route * Patients undergoing TAVI via the transapical approach due to friable or mobile atherosclerotic plaque in the aortic arch * 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 * 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-Muscle Brain have not returned to within normal limits at the time of procedure. * Patients who are currently experiencing clinical symptoms consistent with new-onset AMI, such as nitrate-unresponsive prolonged chest pain * 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 * Patients with known other mental or physical 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 * Patients with severe allergy to heparin or known hypersensitivity or contraindication to aspirin, heparin/bivalirudin, clopidogrel, nitinol, stainless steel alloy, and/or contrast sensitivity that cannot be adequately pre-medicated * Patients with a history of a stroke or transient ischemic attack (TIA) within the prior 6 months * Patients with an active peptic ulcer or history of upper gastrointestinal (GI) bleeding within the prior 6 months * Patients with renal failure (estimated Glomerular Filtration Rate \[estimated Glomerular Filtration Rate\] \<30 mL/min, calculated from serum creatinine by the Cockcroft-Gault formula) * Patients with hepatic failure (Child-Pugh class C) * Patients with hypercoagulable states that cannot be corrected by additional periprocedural heparin * Patients presenting with cardiogenic shock or severe hypotension (systolic blood pressure \<90 mm Hg) at the time of the index procedure * Patients with severe peripheral arterial disease that precludes delivery sheath vascular access * Patients with a heavily calcified or severely atheromatous aortic arch * Patients with an innominate artery ostium diameter \<11 mm * Patients with a transverse aortic diameter \>40 mm * Patients with anatomic irregularities of the aortic arch or innominate artery that could prevent positioning and stability of the device * Patients with contraindication to cerebral MRI * Patients who have a planned treatment with any other investigational device or procedure during the study period * Patients planned to undergo any other cardiac surgical or interventional procedure (e.g., concurrent coronary revascularization) during the TAVI procedure or within two (2) weeks prior to the TAVI procedure.