Safety and Effectiveness of Balloon-Expandable Bioprosthetic SAPIEN X4 Transcatheter Heart Valve in Failing Aortic Bioprosthetic Valves

Inclusion Criteria: 1. Failing aortic bioprosthetic valve demonstrating ≥ moderate stenosis and/or ≥ moderate insufficiency 2. Bioprosthetic valve size suitable for SAPIEN X4 THV 3. NYHA functional class ≥ II 4. Heart Team agrees the subject is at high or greater surgical risk 5. The subject has been informed of the nature of the study, agrees to its provisions and has provided written informed consent. Exclusion Criteria: 1. Anatomical characteristics that would preclude safe femoral placement of the introducer sheath or safe passage of the delivery system 2. Failing valve has moderate or…