A valve repair system, preferably including an annuloplasty prosthesis and a holder for the prosthesis. The holder includes a first component having a central opening, a circumferential surface and an outwardly extending member. The annuloplasty prosthesis is located adjacent to the circumferential surface, above the outwardly extending member. The holder further includes a second component movable upwardly relative to the first holder component and includes a rigid penetrating member extending downward from the second component into the prosthesis, holding it adjacent the circumferential surface. The holder also includes a suturing guide for assisting a physician in valve repair surgery, which may be a cuttable suture extending across the central opening along a path approximating a desired line of leaflet coaption. The cuttable suture may additionally secure the first and second components to one another. The suturing guide may also be incorporated into one-piece annuloplasty prosthesis holders or into stand-alone tools that do not carry annuloplasty prostheses.