A method is provided, including, during a percutaneous transcatheter procedure, placing an annuloplasty device entirely around an annulus of a mitral valve of a subject in a closed loop. The annuloplasty device includes a flexible sleeve, which is fastened to the annulus by coupling a plurality of tissue anchors to a posterior portion of the annulus, without coupling any tissue anchors to any anterior portion of the annulus between left and right fibrous trigones of the annulus. After (a) placing the annuloplasty device entirely around the annulus in the closed loop and (b) fastening the flexible sleeve to the annulus, a longitudinal portion of the flexible sleeve is longitudinally contracted. Other embodiments are also described.