ACURATE Neo™ AS Aortic Bioprosthesis for Implantation Using the ACURATE neoTM AS TF Transfemoral Delivery System in Patients With Severe Aortic Stenosis

Inclusion Criteria: 1. Patient 75 years of age and older 2. Severe aortic stenosis defined as: * Mean aortic gradient \> 40 mmHg or * Peak jet velocity \> 4.0 m/s or * Aortic valve area of \< 1.0 cm2 3. High risk candidate for conventional AVR defined as: * Logistic EuroSCORE 1 ≥ 20% or * STS Score ≥ 8% or * Heart team (cardiologist and cardiac surgeon) consensus that patient is not a surgical candidate for conventional AVR due to significant co-morbid conditions unrelated to aortic stenosis 4. NYHA Functional Class \> II 5. Aortic annulus diameter from ≥ 21mm up to ≤ 27mm by CT 6. Patient willing to participate in the study and provides signed informed consent Exclusion Criteria: 1. Congenital aortic stenosis or unicuspid or bicuspid aortic valve 2. Non-stenotic Aortic Insufficiency 3. Severe eccentricity of calcification 4. Severe mitral regurgitation (\>2+) 5. Presence of mitral bioprosthesis 6. Presence of previously implanted aortic bioprosthesis 7. Presence of prosthetic ring 8. Anatomy NOT appropriate for transfemoral implant due to the size, disease and degree of calcification or tortuosity of the aorta or ilio-femoral arteries 9. Thoracic (TAA) or abdominal (AAA) aortic aneurysm 10. Presence of endovascular stent graft for treatment of TAA or AAA 11. Trans-oesophageal echocardiogram (TEE) is contraindicated 12. Evidence of intra-cardiac mass, thrombus or vegetation 13. Severe ventricular dysfunction with ejection fraction \< 20% 14. Any percutaneous intervention, except for balloon valvuloplasty (BAV) within 1 month prior to implant procedure 15. Acute Myocardial Infarction within 1 month prior to implant procedure 16. Previous TIA or stroke within 3 months prior to implant procedure 17. Active ulcer or gastrointestinal (GI) bleeding within 3 months prior to implant procedure 18. Any scheduled surgical or percutaneous procedure to be performed prior to 30 day visit 19. Severe coagulation conditions 20. Refusal of blood transfusions 21. Systolic pressure \<80mmHg, cardiogenic shock, need for inotropic support or IABP 22. Hypertrophic cardiomyopathy with or without obstruction 23. Active bacterial endocarditis or other active infections 24. Hepatic failure (\> Child B) 25. Chronic renal dysfunction with serum creatinine \> 2.5 mg/dL or renal dialysis 26. Refusal of surgery 27. Severe COPD requiring home oxygen 28. Neurological disease severely affecting ambulation or daily functioning, or dementia 29. Life expectancy \< 12 months due to non-cardiac co-morbid conditions 30. Inability to tolerate anticoagulation therapy 31. Contraindication to contrast media or allergy to nickel 32. Currently participating in an investigational drug or another device study 33. Non-valvular aortic stenosis 34. Non-calcific acquired aortic stenosis