A system for using a helical retainer in the treatment of mitral valve regurgitation by reshaping the mitral valve annulus using one or more plications of annular tissue each fixed by a retaining clip is described. The system includes four devices to achieve such percutaneous direct plication annuloplasty. The first is a preferably prolapsable crossing catheter. Second, a deflecting guide catheter is used to provide a means for guiding the plication device into proper position at the subvalvular region of the mitral valve annulus. Third, the plication device is then used to make plications in at or near the subvalvular region of the mitral valve annulus. Fourth, a helical retainer clip deployed by the plication device in order to retain the plicated tissue in the plicated form. Alternatively, the fourth device is a retainer delivery catheter that enables delivery of a helical retainer over the outside of the plication device.