The Nordic Aortic Valve Intervention Trial

Inclusion Criteria: * Patients must have severe degenerative aortic valve stenosis (echocardiographic criteria: AV effective orifice area (EOA) of \< 1 cm2, mean AV gradient of \> 40 mmHg, or AV peak systolic velocity of \> 4.0 m/s) * Patients must be symptomatic from the aortic valve stenosis (dyspnoea in NYHA-class II or greater, angina pectoris, or syncope), or asymptomatic but with echocardiographic evidence of left ventricular hypertrophy, decreased left ventricular ejection fraction, or atrial fibrillation) * Patients must be 70 years or older * Patients must be technical and anatomical eligible for both interventions (as specified by Medtronic CoreValve(TM) for the TAVI procedure) after a formal consult by a cardiologist and a cardiovascular surgeon * Patients must be expected to survive more than one year after the intervention * Patients must be able to provide written informed consent as approved by the regional ethical committee after having received adequate information about the study * Patients must be able and agree to return to all post-procedural follow-up visits Exclusion Criteria: * Isolated aortic valve insufficiency * Other significant heart valve disease requiring intervention * Coronary artery co-morbidity requiring revascularisation * Any previous open heart surgery * Myocardial infarction or percutaneous coronary intervention within the last year * Stroke or TIA within the last 30 days * Renal insufficiency requiring hemodialysis * Pulmonary insufficiency (FEV1 or diffusion capacity \< 40% of expected) * Active infectious disease requiring antibiotics * Emergency intervention (within 24 hours after the indication for intervention has been made) * Unstable pre-interventional condition requiring inotropic support or mechanical heart assistance * A known hypersensitivity or contraindication to heparin or nitinol * Currently participating in an investigational drug or another device study