Patients with symptomatic severe aortic valve stenosis (valve area <0.8 cm2) are considered candidates for TAVI (TAVR) if they have a logistic European System for Cardiac Operative Risk Evaluation score (EuroSCORE) ≥15% or surgery is deemed to be at excessive risk because of comorbidities and other risk factors not being captured by these scoring systems. Indication for TAVI in the individual patient is discussed in a consensus conference of cardiologists and cardiac surgeons, and patient's or physician's preference alone is not considered adequate for decision making. The performance of TAVI in these patients is approved by the local authorities. All patients have to agree to participate in the study, and written informed consent is obtained.