A medical device in cardiac surgery for replacement of the diseased native heart valves in humans increases thromboresistance of heart valve prosthesis. A heart valve prosthesis comprising an annular housing with the inner surface defining the blood flow I through the valve prosthesis and leaflets mounted within the annular housing with the possibility to pivot around the reference axis between an open position which allows the passage of the direct blood flow I, and a closed position which restricts the blood backflow II. Each leaflet has an upstream surface facing the direct blood surface I, a downstream surface facing the blood backflow II, a coaptation surface, and a side surface.
