This application discloses a variety of approaches for installing a cinching cord onto a cardiac valve annulus and for positioning an annulus ring onto a cardiac valve annulus. One aspect of the invention is directed to an apparatus for cinching a cardiac valve annulus. This apparatus comprises a catheter and a ring of material configured for delivery to the vicinity of a cardiac valve annulus via the catheter. The ring has an external surface. A plurality of whisker-like are barbs disposed on the external surface of the ring, and the barbs are configured to engage tissue when pressed against the tissue. The barbs are also configured to hold the ring in place until tissue ingrowth strengthens a bond between the ring and the annulus.
