A tissue-engaging element has a distal portion configured to engage a portion of tissue of the heart. A guide member is reversibly coupled to the tissue-engaging element. An elongate implant has a distal end and a proximal end, at least the distal end being slidably coupled to the guide member. A tool is slidable along the guide member distally toward the tissue-engaging element while (i) the tool is coupled to at least the distal end of the elongate implant, and (ii) the guide member is coupled to the tissue-engaging element, such that sliding of the tool along the guide member distally toward the tissue-engaging element while (i) the tool is coupled to at least the distal end of the elongate implant, and (ii) the guide member is coupled to the tissue-engaging element, slides at least the distal end of the elongate implant toward the tissue-engaging element.