Chronic mitral regurgitation treatment


 * Associate Editor-In-Chief: ; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.

Overview
Vasodilator theray with ACE inhibitors and hydralazine is the mainstay of therapy in patient with chronic compensated mitral regurgitation. Acute mitral regurgitation requires urgent mitral valve repair or mitral valve replacement. MV surgery is indicated in patients with chronic aortic regurgitation who develop symptomatic mitral valve regurgitation. It is also indicated in patients with abnormalities in LV size or function (These include a left ventricular ejection fraction (LVEF) of less than 60% and a left ventricular end systolic dimension (LVESD) of greater than 45 mm), pulmonary hypertension, or new onset atrial fibrillation even without symptoms. The patient with severe LV dysfunction (an LVEF < 30% and/or a left ventricular end-systolic dimension greater than 55 mm) poses a higher risk but may undergo surgery if chordal preservation is likely. MV repair is recommended over MV replacement in the majority of patients with severe chronic MR who require surgery, and patients should be referred to surgical centers experienced in MV repair.

Medical Therapy of Chronic Mitral Regurgitation
Vasodilator therapy is a mainstay of medical therapy in the management of chronic mitral regurgitation. In the chronic state, the most commonly used agents are ACE inhibitors and hydralazine. Studies have shown that the use of ACE inhibitors and hydralazine can delay surgical treatment of mitral regurgitation.

Surgical Therapy for Chronic Mitral Regurgitation
There are two surgical options for the treatment of mitral regurgitation: mitral valve replacement and mitral valve repair. In general, mitral valve repair is preferred to mitral valve replacement as it carries a lower risk of subsequent prosthetic valve endocarditis and results in better preservation of left ventricular function.

Scenarios Favoring Mitral Valve Repair

 * The ACC/AHA 2008 guidelines recommend mitral valve repair rather than mitral valve replacement if the anatomy is appropriate, including patients with rheumatic mitral valve disease and mitral valve prolapse (Grade 1C). The procedure should be performed at experienced surgical centers.
 * Limited damage to certain areas of the mitral valve leaflets or chordae tendineae.
 * Limited calcification of the leaflets or annulus
 * Prolapse of less than one-third of either leaflet
 * Pure annular dilatation
 * Valvular perforations
 * Incomplete papillary muscle rupture

Scenarios Favoring Mitral Valve Replacement

 * Extensive calcification or degeneration of a leaflet or annulus
 * Prolapse of more than one-third of the leaflet tissue
 * Extensive chordal fusion, calcification, or papillary muscle rupture
 * Extensive damage of mitral valve secondary to endocarditis

==ACC/AHA Guidelines- Indications for Surgery for Mitral Regurgitation (DO NOT EDIT) == {{cquote|

Class I
1. MV surgery is recommended for the symptomatic patient with acute severe MR. (Level of Evidence: B)

2. MV surgery is beneficial for patients with chronic severe MR and NYHA functional class II, III, or IV symptoms in the absence of severe LV dysfunction (severe LV dysfunction is defined as ejection fraction less than 0.30) and/or end-systolic dimension greater than 55 mm. (Level of Evidence: B)

3. MV surgery is beneficial for asymptomatic patients with chronic severe MR and mild to moderate LV dysfunction, ejection fraction 0.30 to 0.60, and/or end-systolic dimension greater than or equal to 40 mm. (Level of Evidence: B)

4. MV repair is recommended over MV replacement in the majority of patients with severe chronic MR who require surgery, and patients should be referred to surgical centers experienced in MV repair. (Level of Evidence: C)

Class IIa
1. MV repair is reasonable in experienced surgical centers for asymptomatic patients with chronic severe MR with preserved LV function (ejection fraction greater than 0.60 and end-systolic dimension less than 40 mm) in whom the likelihood of successful repair without residual MR is greater than 90%. (Level of Evidence: B)

2. MV surgery is reasonable for asymptomatic patients with chronic severe MR, preserved LV function, and new onset of atrial fibrillation. (Level of Evidence: C)

3. MV surgery is reasonable for asymptomatic patients with chronic severe MR, preserved LV function, and pulmonary hypertension (pulmonary artery systolic pressure greater than 50 mm Hg at rest or greater than 60 mm Hg with exercise). (Level of Evidence: C)

4. MV surgery is reasonable for patients with chronic severe MR due to a primary abnormality of the mitral apparatus and NYHA functional class III–IV symptoms and severe LV dysfunction (ejection fraction less than 0.30 and/or end-systolic dimension greater than 55 mm) in whom MV repair is highly likely. (Level of Evidence: C)

Class IIb
1. MV repair may be considered for patients with chronic severe secondary MR due to severe LV dysfunction (ejection fraction less than 0.30) who have persistent NYHA functional class III–IV symptoms despite optimal therapy for heart failure, including biventricular pacing. (Level of Evidence: C)

Class III
1. MV surgery is not indicated for asymptomatic patients with MR and preserved LV function (ejection fraction greater than 0.60 and end-systolic dimension less than 40 mm) in whom significant doubt about the feasibility of repair exists. (Level of Evidence: C)

2. Isolated MV surgery is not indicated for patients with mild or moderate MR. (Level of Evidence: C)}}