ACURATE™ Transapical Aortic Bioprosthesis for Implantation in Patients With Severe Aortic Stenosis (2010-01)

Inclusion Criteria: 1. Patients at least 75 years of age 2. Additive EuroSCORE \> 9 3. Severe AS assessed by echocardiography and documented by a mean gradient \> 40mmHg and a native Aortic Valve Area (AVA) \< 0.8 cm² or Aortic Valve Area Index (AVAI) \< 0.6 cm²/m² 4. NYHA Functional Class \> II 5. Aortic annulus (AAn) diameters between and including 21 mm up to 27 mm (21mm ≤ AAn ≤27mm) by transoesophageal echocardiography (TEE) 6. Patient understands the implications of participating in the study and provides signed informed consent Exclusion Criteria: 1. Congenital unicuspid or bicuspid aortic valve 2. Severe eccentricity of calcification 3. Severe mitral regurgitation (\> 2°) 4. Pre-existing prosthetic heart valve in any position and / or prosthetic ring 5. Severe transapical access problem, non-reachable LV apex 6. Previous surgery of the LV using a patch, such as the Dor procedure 7. Presence of apical LV thrombus 8. Echocardiographic evidence of intracardiac mass, thrombus, or vegetation 9. Acute myocardial infarction (AMI) within 1 month prior to the procedure 10. PCI within 1 month prior to the procedure 11. Previous transient ischemic attack (TIA) or stroke in the last 3 months 12. Untreated clinically significant coronary artery disease (CAD) requiring revascularization 13. Hemodynamic instability: systolic pressure \<90mmHg without afterload reduction, shock, need for inotropic support or intra-aortic balloon pump 14. Severe left ventricular dysfunction (LVEF) \< 30% by echocardiography 15. Calcified pericardium 16. Septal hypertrophy unacceptable for transapical procedure 17. Primary hypertrophic obstructive cardiomyopathy (HOCM) 18. Active infection, endocarditis or pyrexia 19. Active peptic ulcer or gastrointestinal (GI) bleeding within the past 3 months 20. Significant hepatic involvement (Child \> B) 21. Severe COPD requiring home oxygen 22. History of bleeding diathesis or coagulopathy 23. Hematologic disorder (WBC \< 3000mm3, Hb \< 9g/dL, platelet count \< 50000 cells/ mm3) 24. Chronic renal dysfunction with a serum creatinine level \> 2.5 mg/dL or renal failure requiring dialysis 25. Neurological disease severely affecting ambulation or daily functioning, including dementia 26. Another surgical or percutaneous procedure scheduled at the same time 27. Emergency procedure 28. Life expectancy \< 12 months due to non-cardiac co-morbid conditions 29. Known hypersensitivity/contraindication to any study medication, contrast media, or nitinol 30. Currently participating in an investigational drug or another device study