Mechanisms Of Disease Progression in Aortic Stenosis - the MODAS Study

Inclusion Criteria: * The patient has an acquired (tricuspid) moderate aortic valve stenosis, which is the reason for regular outpatient cardiological care. * The subject has been informed verbally and in writing about the study and has given written consent to participate in this study. * Age \> 18 years Exclusion Criteria: * The subject has contraindications for the performance of a magnetic resonance imaging or computed tomography (e.g., severe arrhythmias , contrast agent intolerance, a pacemaker, or severe renal insufficiency or severe renal insufficiency or claustrophobia). * Presence of only mild or already high-grade acquired tricuspid Aortic valve stenosis * Patient with bicuspid aortic valve * Inability to follow the instructions of study personnel * Lack of written informed consent