Inclusion Criteria:
1. Patient above 18 years of age.
2. Patients must have co-morbidities such that the heart team and Investigator concur that the predicted risk of operative mortality is high.
3. Patient has non- or mild-calcified aortic regurgitation, undergoing TAVI with Myval THV Series without any degree stenosis, and severe aortic regurgitation as per investigator/ Heart team discretion according to (at least one) imaging criteria that can include:
1. Echocardiographically derived criteria: regurgitant volume ≥60 ml/beat, regurgitant fraction ≥50%, effective regurgitant orifice ≥0.3cm2, holodiastolic flow reversal at the level of the mid-descending aorta with an end diastolic flow velocity greater than 20 cm/s, width of vena contracta ≥6mm, hemi pressure time \<200 msec, or vena contracta area assessed with 3D echo ≥0.4 cm².
AND/OR
2. Cardiac magnetic resonance derived criteria: Regurgitant fraction \>40% or regurgitant volume \>60mL.
4. Patient suitable for implantation with Myval THV series via transfemoral approach.
5. Patient is symptomatic from his/her aortic valve regurgitation, as demonstrated by the New York Heart Association (NYHA) Functional Class ≥II.
6. Patient or the patient's legal representative has been informed of the nature of the study, agrees to its provisions and has provided written informed consent as approved by the Institutional Review Board (IRB)/Ethics Committee of the respective clinical site.
7. The patient and the treating physician agree that the patient will return for all required post-procedure follow-up visits.
Exclusion Criteria:
1. Patients who are not willing to provide informed consent form, or whose legal heirs object to participate in the study
2. Pregnant and lactating female patients
3. Evidence of an acute myocardial infarction ≤1 month before the intended treatment
4. Mixed aortic valve disease
5. Moderate-severe calcification of aortic valve
6. Bicuspid aortic valve disease according to treating physician (if detected by the corelab it will not be excluded except if so considered by the steering committee)
7. Congenital unicuspid patients
8. Any therapeutic invasive cardiac procedure performed within 30 days of the index procedure, (or 6 months if the procedure was a drug eluting coronary stent/scaffold implantation).
9. Pre-existing prosthetic heart valve in any position, prosthetic ring, severe mitral annular calcification (MAC), severe (greater than 3+) mitral insufficiency, or Gorlin syndrome.
10. Blood dyscrasias as defined: leukopenia (WBC\<3000 mm3), acute anemia (Hb\<9 mg/dl), thrombocytopenia (platelet count \<50,000 cells/mm3), history of bleeding diathesis or coagulopathy.
11. Untreated clinically significant coronary artery disease requiring revascularization.
12. Hemodynamic instability requiring inotropic support or mechanical heart assistance.
13. Need for emergency surgery other than aortic valve replacement with the study device.
14. Hypertrophic cardiomyopathy with or without obstruction (HOCM).
15. Very severe ventricular dysfunction with left ventricular ejection fraction (LVEF) \<15%.
16. Echocardiographic evidence of intracardiac mass, thrombus or vegetation.
17. Active peptic ulcer or upper GI bleeding within the prior 3 months.
18. A known hypersensitivity or contraindication to aspirin, heparin, ticlopidine (Ticlid), or clopidogrel (Plavix), or sensitivity to contrast media, which cannot be adequately premedicated.
19. Recent (within 6 months) cerebrovascular accident (CVA) or a Transient Ischemic Attack (TIA).
20. Renal insufficiency and/or end stage renal disease requiring chronic dialysis
21. Life expectancy \<1 year due to non-cardiac co-morbid conditions.
22. Significant aortic disease, including abdominal aortic or thoracic aneurysm defined as maximal luminal diameter 5cm or greater; marked tortuosity (hyperacute bend), aortic arch atheroma or narrowing (especially with calcification and surface irregularities) of the abdominal or thoracic aorta, severe "unfolding" and tortuosity of the thoracic aorta (applicable for transfemoral patients only) which would make Transcatheter Aortic Valve Implantation (TAVI) unfeasible as per the Investigator/Heart Team.
23. Iliofemoral vessel characteristics that would preclude safe placement of introducer sheath such as severe obstructive calcification, severe tortuosity or vessels with adequate femoral size (applicable for transfemoral patients only).
24. Currently participating in an investigational drug or another device study which has not achieved the primary endpoint.
25. Active bacterial endocarditis or other active infections.
26. Any condition, which in the Investigator's opinion, would preclude safe participation of patient in the study.
