Recombinant Human C1 Esterase Inhibitor (Conestat Alfa) in the Prevention of Acute Ischemic Cerebral and Renal Events After Transcatheter Aortic Valve Implantation

In the current study, participants will receive two intravenous injections of conestat alfa (immediately during the TAVI procedure and again 3h later) at a dose of 100 U/kg (first dose) and of 50 U/kg (subsequent dose), for patients less than 84 kg; two intravenous injections (immediately during the TAVI procedure and again 4h later) of conestat at a dose of 8400 U (4 vials, first dose) and of 4200 U (2 vials, subsequent dose) for patients of 84 kg body weight or greater. The chosen regimen including repeated administration should increase and maintain serum C1INH levels above twice the serum concentration for six to eight hours in the majority of patients. The timeframe of therapeutic concentrations will cover the period of the TAVI procedure itself and the immediate postprocedural period during which reperfusion and additional ischemic events related to global hypoperfusion may occur.

Normal saline (NaCl 0.9%) will serve as placebo treatment. The respective amount of saline (according to patient weight matching the volume of conestat alfa that would have been used for this patient) will be withdrawn in an opaque syringe for slow IV injection.