Clinical Research Directory

Inclusion Criteria: 1. Patient has moderate or greater aortic stenosis or regurgitation, and there is 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: i. Left atrial appendage (LAA) ligation ii. CABG (coronary artery bypass grafting) iii. Patent foramen ovale (PFO) closure iv. Ascending aortic aneurysm or dissection repair not requiring circulatory arrest v. Resection of a sub-aortic membrane not requiring myectomy 2. Patient is geographically stable and willing to return to the implanting site for all follow-up visits 3. Patient is of legal age to provide informed consent in the country where they enroll in the trial 4. Patient has been adequately informed of risks and requirements of the trial and is willing and able to provide informed consent for participation in the clinical trial Exclusion Criteria: 1. Patient 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. Patient has had previous implant and then explant of the Model 400 aortic valve bioprosthesis 3. Patient presents with active endocarditis, active myocarditis or other systemic infection 4. Patient has an anatomical abnormality which would increase surgical risk of morbidity or mortality, including: * Ascending aortic aneurysm or dissection repair requiring circulatory arrest * Acute Type A aortic dissection * Ventricular aneurysm * Porcelain aorta * Hostile mediastinum * Hypertrophic obstructive cardiomyopathy (HOCM) * Documented pulmonary hypertension (systolic \>60mmHg) 5. Patient has a non-cardiac major or progressive disease, with a life expectancy of less than 2 years. These conditions include, but are not limited to: * Child-Pugh Class C liver disease * Terminal cancer * End-stage lung disease 6. Patient has renal failure, defined as dialysis therapy or glomerular filtration rate(GFR)\<30 mL/min/1.73 m2 7. Patient has hyperparathyroidism 8. Patient is participating in another investigational device or drug trial or observational competitive study 9. Patient is pregnant, lactating or planning to become pregnant during the trial period 10. Patient has a documented history of substance (drug or alcohol) abuse 11. Patient has greater than mild mitral valve regurgitation or greater than mild tricuspid valve regurgitation as assessed by echocardiography 12. Patient has systolic ejection fraction (EF)\<20% as assessed by echocardiography 13. Patient has Grade IV Diastolic Dysfunction 14. Patient has documented bleeding diatheses 15. Patient has had an acute preoperative neurological deficit or myocardial infarction and has not returned to baseline or stabilized ≥30 days prior to enrollment 16. Patient requires emergency surgery