Abstract: An assembly comprising a prosthetic heart valve having a plurality of commissure supports which are deflectable radially inwardly and a valve holder which includes inner and outer holder members mounted for movement toward and away from each other. The valve holder is attached to the heart valve by sutures which extend from the outer holder member to the commissure supports and then between the commissure supports. When a handle is attached to the other holder member, the holder members are forced apart to tension the sutures to deflect the commissure supports radially inwardly. Portions of the sutures extend between the commissure supports to form a suture loop guard.