Patients with severe MR who develop an LVEF <60% or LVESD 40 mm have already developed LV systolic dysfunction.5,6 One study has sug- gested that for LV function and size to return to normal after mitral valve repair, the LVEF should Thus, when lon- gitudinal follow-up demonstrates a progressive decrease of LVEF toward 60% or a progressive increase in LVESD approaching 40 mm, it is rea- sonable to consider intervention.41 In severe MR, TTE is recommended at 3- to 6-month intervals or more frequently as the ventricle enlarges. 6. Mitral transcatheter edge-to-edge repair (TEER) with the anterior and posterior leaflets clipped together at 1 locations is safe and effective in treating severely symptomatic patients with pri- mary MR who are at high or prohibitive surgi- Studies of TEER with a mitral valve clip have demonstrated improved symptoms and a reduction in MR by 2 to 3 grades, leading to reverse remodeling of the LV. Superior outcomes were shown with surgery versus TEER, and thus it is only the patients who are at high or prohibitive risk for surgery for whom TEER is performed. 7. Rheumatic mitral valve disease is less suitable for mitral repair compared with complex degenera- tive disease. Durability of the repair is limited by thickened or calcified leaflets, extensive subval- vular disease with chordal fusion and shortening, and progression of rheumatic disease. Freedom from reoperation at 20 years, even in experienced hands, is in the 50% to 60% range. In a large series from Korea, repair was accomplished in 22% of patients operated on for rheumatic dis- One-third of these patients who underwent repair had significant stenosis or regurgitation at 10 years. 