Regent China Post-Market Clinical Follow-up Study

Inclusion Criteria: 1. Patient is eligible to be implanted with Regent to replace a native or prosthetic aortic valve per Regent's IFU. 2. Subject will be \>18 years of age at time of being consented. 3. Subject, provides written informed consent prior to any clinical investigation-specific procedure. Exclusion Criteria: 1. Subject is unable to tolerate anticoagulation therapy. 2. Subject has active endocarditis. 3. Subject is currently participating in another clinical investigation which may interfere with the effectiveness of anticoagulation therapy. 4. Pregnant or nursing subjects and those who plan pregnancy during the clinical investigation follow-up period. Women of child-bearing potential must have a documented negative pregnancy test within one week prior to enrollment. 5. Subject has anomalous anatomy or medical, surgical, psychological or social history or conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements of the clinical investigation results. 6. Subject is unable to read or write or has a mental illness or disability that impairs their ability to provide written informed consent. 7. Subject's life expectancy is less than 1 year in the opinion of the Investigator.