Avalus Ultra Post-Approval Study (PAS)

The purpose of this study is to characterize the safety and effectiveness of the Medtronic Avalus Ultra aortic valve bioprosthesis in patients with aortic valve disease.

A prospective, multi-center, single-arm, interventional, non-randomized, post-market study to characterize the safety and effectiveness of the Medtronic Avalus Ultra aortic valve bioprosthesis in patients with aortic valve disease. Approximately 150 subjects in the United States will be implanted and followed through one year post-procedure.

Inclusion Criteria Subjects must meet the following criteria to be included in the study: 1. Subject has moderate or greater aortic stenosis or regurgitation, and there is a clinical indication for replacement of their native or prosthetic aortic valve with a bioprosthesis, with or without concomitant procedures, which are limited to any of the following: * Atrial fibrillation (AF) ablation * Ascending aortic aneurysm or dissection repair or replacement, with or without circulatory arrest * Coronary artery bypass graft (CABG) * Surgical management of the left atrial appendage (LAA) * Patent foramen ovale (PFO) closure * Resection of a sub-aortic membrane not requiring myectomy 2. Subject is geographically stable and willing to return to the implanting site for all follow-up visits 3. Subject is of legal age to provide informed consent 4. Subject has been adequately informed of risks and requirements of the study and is willing and able to provide informed consent for participation in the study Exclusion Criteria Subjects who meet any of the following criteria will not be eligible for participation in the study: 1. Subject has a pre-existing prosthetic valve or annuloplasty device in another position or requires replacement or repair of the mitral, pulmonary, or tricuspid valve 2. Subject has had a previous implant and then explant of the Avalus Ultra aortic valve bioprosthesis within the Avalus Ultra Post-Approval Study 3. Subject presents with active endocarditis, active myocarditis, or other systemic infection 4. Subject has a known hypersensitivity to contrast media that cannot be adequately premedicated 5. Subject has a known hypersensitivity to platinum, iridium, or tantalum 6. Subject has an anatomical abnormality that would increase surgical risk of morbidity or mortality, including: * Acute Type A aortic dissection * Ventricular aneurysm * Porcelain aorta * Hostile mediastinum * Hypertrophic obstructive cardiomyopathy * Documented pulmonary hypertension (systolic \>60mmHg) 7. Subject has a non-cardiac major or progressive disease with a life expectancy of less than 1 year. These conditions include but are not limited to: * Child-Pugh Class C liver disease * Terminal cancer * End-stage lung disease 8. Subject has renal failure, defined by dialysis therapy or glomerular filtration rate (GFR) \<30 mL/min/1.73 m2 9. Subject has active or untreated hyperparathyroidism 10. Subject is participating in another investigational device or drug trial (not including registries) 11. Subject is pregnant, lactating, or planning to become pregnant during the study period 12. Subject has a documented history of substance (drug or alcohol) abuse 13. Subject has greater than mild mitral valve regurgitation or greater than mild tricuspid valve regurgitation as assessed by echocardiography 14. Subject has systolic ejection fraction (EF) \<20% as assessed by echocardiography 15. Subject has Grade IV diastolic dysfunction 16. Subject has documented bleeding diatheses 17. Subject has had an acute preoperative neurological deficit or myocardial infarction and has not returned to baseline or stabilized ≥30 days prior to implant 18. Subject requires emergency surgery