Method of manufacturing a heart valve prosthes

The present invention provides a cardiac valve prosthesis comprising a frame (1) and two or more leaflets (2a, 2b) (preferably three) attached to the frame. The leaflets are attached to the frame between posts (8), with a free edge (3a, 3b) which can seal the leaflets together when the valve is closed under back pressure. The leaflets are created in a mathematically defined shape allowing good wash-out of the whole leaflet orifice, including the area close to the frame posts, thereby relieving the problem of thrombus deposition under clinical implant conditions.