Methods and apparatus for controlled grasping and cinching or locking of a tissue anchor are provided. In one variation, a tube is provided having a lumen and a resilient member that obstructs the lumen. A grasper may be advanced coaxially through the lumen, such that it reversibly displaces the resilient member and extends beyond the lumen's outlet to engage an element of the tissue anchor. The grasper then may be retracted within the tube, such that the resilient member again obstructs the lumen of the tube. Continued retraction of the grasper may act to cinch the anchor, for example, via interaction between the anchor and the obstructing resilient member. During cinching, a cinching mechanism of the anchor optionally may be positioned at least partially within the tube to enhance lateral stability. Furthermore, feedback indicative of a degree of cinching or locking may be provided during cinching.