PARTNER 3 Trial - Aortic Valve-in-Valve

Inclusion Criteria: 1. Failing surgical or transcatheter bioprosthetic valve in the aortic position demonstrating ≥ moderate stenosis and/or ≥ moderate insufficiency. 2. Bioprosthetic valve with a true internal diameter (True ID) of 18.5 mm to 28.5 mm. 3. NYHA Functional Class ≥ II. 4. Heart Team agrees the patient is low to intermediate risk. 5. Heart Team agrees valve implantation will likely benefit the patient. 6. The study patient has been informed of the nature of the study, agrees to its provisions and has provided written informed consent. Exclusion Criteria: 1. Surgical or transcatheter valve in the mitral position (mitral rings are not an exclusion) 2. Severe regurgitation (\> 3+) or stenosis of any other valve 3. Failing valve has moderate or severe paravalvular regurgitation 4. Failing valve is unstable, rocking, or not structurally intact 5. Increased risk of coronary obstruction by prosthetic leaflets of the failing valve. 6. Increased risk of embolization of THV 7. Known bioprosthetic valve with residual mean gradient \> 20 mmHg at the end of the index procedure for implantation of the original valve 8. Iliofemoral vessel characteristics that would preclude safe placement of the introducer sheath (Transfemoral) 9. Anatomical characteristics that would preclude safe access to the ascending aorta (Transaortic) 10. Anatomical characteristics that would preclude safe access to the apex (Transapical) 11. Evidence of an acute myocardial infarction ≤ 30 days before enrollment 12. Any therapeutic invasive cardiac procedure resulting in a permanent implant that is performed within 30 days prior to the index procedure. Implantation of a permanent pacemaker or implantable cardioverter defibrillator is not considered an exclusion. 13. Patients with planned concomitant surgical or transcatheter ablation for Atrial Fibrillation 14. Leukopenia, anemia, thrombocytopenia, history of bleeding diathesis or coagulopathy or hypercoagulable states 15. Untreated clinically significant coronary artery disease requiring revascularization 16. Hemodynamic or respiratory instability requiring inotropic support, mechanical ventilation, or mechanical heart assistance within 30 days of enrollment 17. Emergency interventional/surgical procedures within 30 days prior to the procedure 18. Any planned surgical, percutaneous coronary, or peripheral procedure to be performed within the 30-day follow-up from the procedure 19. Hypertrophic cardiomyopathy with obstruction 20. LVEF \< 30% 21. Cardiac imaging evidence of intracardiac mass, thrombus, or vegetation 22. Inability to tolerate or condition precluding treatment with antithrombotic/anticoagulation therapy during or after the valve implant procedure 23. Absolute contraindications or allergy to iodinated contrast that cannot be adequately treated with premedication 24. Stroke or transient ischemic attack within 90 days of enrollment 25. Symptomatic carotid or vertebral artery disease or successful treatment of carotid stenosis within 30 days of enrollment 26. Renal insufficiency and/or renal replacement therapy at the time of screening 27. Active bacterial endocarditis within 180 days of the procedure 28. Patient refuses blood products 29. Estimated life expectancy \< 24 months 30. Positive urine or serum pregnancy test in female subjects of childbearing potential 31. Currently participating in an investigational drug or another device study