Inclusion Criteria:  Informed consent as documented by signature Severe AS and scheduled for transfemoral TAVI  Exclusion Criteria:  Contraindications to the class of drugs under study (C1INH), e.g., known hypersensitivity or allergy to class of drugs or the investigational product History of allergy to rabbits (as rhC1INH is derived from the breast milk of transgenic rabbits) Women who are pregnant or breast feeding Hemodynamic instability requiring emergency TAVI Valve-in-valve procedure Other access route than transfemoral Non-cardiac co-morbidity with expected survival <6 months Ischemic or hemorrhagic stroke within 30 days before TAVI Dialysis or estimated glomerular filtration rate (eGFR) <20 ml/min/1.73m2 Contraindication for MRI such as a permanent non-MRI compatible pacemaker or severe claustrophobia Liver cirrhosis (any Child-Pugh score) Incapacity or inability to provide informed consent Participation in another study with investigational drug or medical device within the 30 days preceding and during the present study Previous enrolment into the current study Any uncontrolled or significant concurrent illness that would put the patient at a greater risk or limit compliance with the study requirements at the discretion of the investigator