Patent ID: 8052750

Claim:
Apparatus comprising a prosthesis for implantation at a native semilunar valve of a native valve complex of a subject, the native valve complex having semilunar sinuses and native commissures, the prosthesis comprising: a distal fixation member, configured to be positioned in a downstream artery of the subject selected from the group consisting of: an ascending aorta, and a pulmonary trunk, and shaped so as to define exactly three strut supports and exactly three proximal engagement arms, wherein each engagement arm is connected to and extends between two of the strut supports, wherein the engagement arms are configured to be positioned at least partially within respective ones of the semilunar sinuses, and, in combination, to apply, to tissue that defines the semilunar sinuses, a first axial force directed toward a ventricle of the subject; and a proximal fixation member coupled to the distal fixation member, the proximal fixation member configured to be positioned at least partially on a ventricular side of the native semilunar valve, and to apply, to the ventricular side of the native valve complex, a second axial force directed toward the downstream artery, such that application of the first and second forces couples the prosthesis to the native valve complex; wherein at least one of the engagement arms includes a local trough at a proximal, upstream portion of the engagement arm.