A device for improving the function of a heart valve comprises: a supportmember formed from a shape memory material, and a restraining member providinga restraining action on a course of the support member. The support member mayabut one side of the valve conforming to the shape of the valve annulus uponsaid shape memory material assuming an activated shape while the restrainingmember restrains the course of the support member. The restraining action isremovable for allowing the support member to assume a desired, altered course.The restraining member may be biodegradable to be degraded within a patient ormay be detachable from the support member to be withdrawn. The support memberaccording to another embodiment presents a shape change in that an increasedcross- section is associated with a shortened length of the support member.The support member according to yet another embodiment has a first and asecond activated shape.
