CoreValve® System Australia/New Zealand Clinical Study

Inclusion Criteria 1. Documented severe aortic valve stenosis 2. Access vessel diameter \>6 mm as defined pre procedure via angiographic measure 3. Aortic valve annulus diameter ≥ 20 mm and \< 29 mm as defined pre procedure by echocardiographic measure 4. Ascending aorta diameter ≤ 43 mm at the sino-tubular junction 5. Native aortic valve disease, defined as valve stenosis with an aortic valve area\<1cm2 (\<0.6cm2 /m2) as defined pre procedure by echocardiographic measure AND (Assessment of Surgical Risk) Age ≥ 80 years AND/OR Surgical risk calculated with logistic EuroSCORE ≥ 20%, AND/OR Age ≥ 65 years with one or two (but not more than 2) of the following criteria: * Cirrhosis of the liver (Child class A or B) * Pulmonary insufficiency : VMS \< 1 liter * Previous cardiac surgery (CABG, valvular surgery) * Porcelain aorta * Pulmonary hypertension \> 60 mmHg and high probability of cardiac surgery for other than valve replacement * Recurrent pulmonary embolus * Right ventricular insufficiency * Thoracic burning sequelae contraindicating open chest surgery * History of mediastinum radiotherapy * Severe connective tissue disease resulting in a contraindication to surgery * Cachexia (clinical impression) 6. Study subjects must be willing and able to attend all follow-up visits within specified visit windows, and agree to undergo all protocol evaluations at each visit Exclusion Criteria: 1. Known hypersensitivity or contraindication to aspirin, heparin, ticlopidine, clopidogrel, nitinol, porcine products, or contrast media which cannot be adequately pre-medicated 2. Any sepsis, including active endocarditis. 3. Recent myocardial infarction (\<30 days) 4. Any left ventricular or atrial thrombus as determined pre procedure by echocardiography 5. Uncontrolled atrial fibrillation 6. Mitral or tricuspid valvular insufficiency (\> grade II) 7. Previous aortic valve replacement (mechanical valve or stented bioprosthetic valve) 8. Evolutive or recent CVA (cerebrovascular accident), (\<3 months) 9. Femoral, iliac or aortic vascular condition (e.g. stenosis, tortuosity), that make impossible insertion and endovascular access to the aortic valve 10. Symptomatic carotid or vertebral arteries narrowing (\> 70%) disease 11. Abdominal or thoracic aortic aneurysm 12. Bleeding diathesis or coagulopathy, or patient will refuse blood transfusion 13. Evolutive disease with life expectancy less than one year 14. Creatinine clearance \< 20 ml/min 15. Active gastritis or known peptic ulcer disease 16. Pregnancy