An artificial heart valve (102) is disclosed. In general, mechanical valves require life-long anticoagulant drug treatment to prevent blood clotting around the valve while biological valves are vulnerable to degeneration that limits their useful life, particularly in children and young adults. If a reasonably priced, reliable heart valve that did not require anticoagulation, and was easy to implant in a conventional operating room, were available, there would be a wide clinical application. Such a valve is disclosed. The valve comprises a support structure (106) defining an aperture for blood flow and a flexible leaflet (104) connected to the support structure along first and second at least partially straight lines of attachment (114). The leaflet is movable relative to the support structure between an open configuration in which the leaflet permits blood flow through the aperture and a closed configuration in which the leaflet restricts blood flow through the aperture. A lateral cross-section taken through the leaflet defines an outwardly convex portion (121), an outwardly concave portion (122) and a junction (118) between the convex and concave portions. The heart valve may be configured for implantation in a human or animal subject. A method of manufacturing a heart valve and a former for use in such a method are also disclosed.
