Method of manufacture of a heart valve prosthesis

A method of manufacturing a cardiac valve prosthesis which includes a frame defining a blood flow axis substantially parallel to the flow of blood through the valve prosthesis and at least two flexible leaflets attached to the frame, the method comprising: providing an element of formation having at least two surfaces forming shells; engaging the forming element to the frame; applying a coating over the frame and engaged forming element, joining the covering to the frame, forming the coating on the surfaces of leaflet forming the at least two flexible leaflets in a neutral position, wherein the at least two leaflets being configured to be movable from an open position to a closed, having the at least two leaflets side blood inlet and an outlet side blood, at least two leaflets being in the closed position when fluid pressure is applied on the output side, being in the open position when fluid pressure is applied to the inlet side and being in a neutral position intermediate the open and closed position in the absence of application of fluid pressure in the leaflets, including at least two leaflets a first leaflet having a first surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave, the first composite wave substantially defined being by a first wave combined with at least a second superimposed wave, the first wave having a first frequency, the second wave having a second frequency, the first frequency different from the second frequency; providing said first composite wave multiple curves in the free edge of the leaflet; and disengaging the forming element from the frame, and wherein the frame is substantially cylindrical having a first and a second end defining one end at least two portions scalloped edge separated by at least two posts, each retaining one tip, wherein each leaflet has a fixed edge joined to a portion of respective scalloped edge of the frame and a free edge extending substantially between the tips of the at least two posts, and wherein when the at least two leaflets are in the neutral position the valve prosthesis has partially open commissures defined by an included angle between the free edges of adjacent leaflets is in the range of 10 ° to 55 °.