CVC indicates Com- prehensive Valve Center; ERO, effective regurgitant orifice; ESD, end-systolic dimension; LVEF, ejection fraction; MR, mitral regurgitation; MV, mitral valve; MVR, mitral valve replacement; RF, regurgitant fraction; RVol, regurgitant volume; and VC, vena contracta. CLINICAL STATEMENTS AND GUIDELINES approach. Thus, there must be a high degree of certainty that a durable repair can be performed. This certainty comes from the track record of the surgical team in operating on the specific type of lesion under consideration. Thus, asymptomatic patients should be treated in a Comprehensive In excellent hands, patients with severe MR from flail leaflets who undergo early operation as opposed to watchful waiting have a lower risk of developing HF and lower 5. MR may lead to progressively more severe MR as the initial level of MR causes LV dilation, which increases stress on the mitral apparatus, caus- ing further damage to the valve apparatus, more severe MR, and further LV dilation thus initiating a perpetual cycle of ever-increasing LV volumes and MR. Longstanding volume overload leads to irreversible LV dysfunction and a poorer progno- sis. 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. 