cardiovascular disorders
Mitral Regurgitation
Treatment of Mitral Regurgitation
Mitral valve repair preferred for primary MR Medical therapy or mitral valve replacement for secondary MR Anticoagulants for patients with atrial fibrillation Angiotensin-converting enzyme (ACE) inhibitors and other vasodilators do not delay LV dilation or MR progression and so have no role in asymptomatic MR with preserved LV function. However, if LV dilation or dysfunction is present, therapy using an angiotensin receptor blocker, neprilysin inhibitor (eg, sacubitril, combined with theangiotensin IIblockervalsartan),aldosteroneantagonist, and/or vasodilating beta-blocker (eg,carvedilol) is indicated. In secondary MR, these medications can reduce the severity of MR and probably improve prognosis. If the ECG shows left bundle branch block, then biventricular pacing may be beneficial for secondary MR. Loop diuretics such asfurosemideare helpful in patients with exertional or nocturnal dyspnea.Digoxinmay reduce symptoms in patients with atrial fibrillation or those in whom valve surgery is not appropriate. Antibiotic prophylaxis is no longer recommended except for patients who have had valve replacement or repair utilizing prosthetic materials (see table). Anticoagulants are used to Prevention in patients with atrial fibrillation. Acute mitral regurgitationrequires emergency mitral valve repair or replacement with concomitant coronary revascularization as necessary. Pending surgery,nitroprussideornitroglycerininfusion and an intra-aortic ballon pump may be used to reduce afterload, thus improving forward stroke volume and reducing ventricular and regurgitant volume. 40 mm). Even in the absence of these triggers, intervention may be beneficial when surgical risk is low and valve morphology suggests a high likelihood of successful repair. Atrial fibrillation, pulmonary hypertension, flail leaflet, and left atrial dilation are not indications for intervention ( Treatment references ). When the EF falls to has fewer indications for intervention. Because the initial pathology involves the LV muscle, correction of MR is not as beneficial and should be considered only when significant symptoms persist despite a trial of guideline-directed medical therapy, including biventricular pacing, if indicated (see Treatment ). Patients with atrial functional mitral regurgitation may benefit from surgery more than patients with other causes of secondary mitral regurgitation (eg, regional or global ischemic changes) ( For patients undergoing cardiac surgery for other indications, concomitant mitral valve surgery should be considered for a repairable valve with MR that is moderate. However, for secondary MR, this practice has been questioned by the 2-year outcome of a randomized comparison with CABG alone. The addition of mitral valve repair did not affect LV remodelling or survival, but an excess of adverse events occurred ( Treatment references ). Therefore, only severe secondary MR should be treated when coronary artery bypass grafting (CABG) is being done to treat ischemia. Inprimary mitral regurgitation,the closer the mitral valve intervention mimics the native valve, the better for LV preservation and mortality. Hence, the order of preference is Repair with leaflet remodelling and chordal replacement Replacement with chordal preservation Replacement with removal of chordae If mitral valve repair with leaflet remodelling and chordal replacement is not feasible, replacement with a mechanical prosthesis is preferred because tissue valves have reduced longevity in the mitral position. A bioprosthesis is an option for patients over the age of 70 years. mitral valve replacement is preferred over repair with a downsized annuloplasty ring because mitral valve replacement results in less mitral regurgitation and heart failure 2 years after treatment ( Treatment references ). When the mechanism of secondary MR is annular dilation due to atrial fibrillation, valve surgery may be beneficial when symptoms cannot be medically controlled. Another method of repair is transcatheter edge-to-edge repair (TEER) with a device that approximates the mitral leaflets. TEER is an option for patients with severe primary MR and New York Heart Association (NYHA) Classification of Heart Failure heart failure symptoms refractory to medical therapy who cannot undergo surgery. In secondary MR, given the lesser benefit of surgery, TEER is indicated even for patients whose surgical risk is not prohibitive if they have In about 50% of decompensated patients, prosthetic valve implantation markedly depresses ejection fraction because in such patients, ventricular function has become dependent on the afterload reduction of MR. For patients with atrial fibrillation, concomitant procedures such as Ablation for Cardiac Arrhythmia and surgically occluding the left atrial appendage to reduce the risk of stroke may be beneficial. for 3 to 6 months postoperatively (see also Anticoagulation for patients with a prosthetic cardiac valve ). Direct-acting oral anticoagulants (DOAC) are ineffective and should not be used. 1.Otto CM, Nishimura RA, Bonow RO, et al: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation143(5):e35–e71, 2021. doi: 10.1161/CIR.0000000000000932 2.Farhan S, Silbiger JJ, Halperin JL, et al: Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation: JACC State-of-the-Art Review [published correction appears inJ Am Coll Cardiol2023 Feb 21;81(7):711].J Am Coll Cardiol80(24):2314–2330, 2022. doi:10.1016/j.jacc.2022.09.046 3.Michler RE, Smith PK, Parides MK, et al: Two-year outcomes of surgical treatment of moderate ischemic mitral regurgitation.N Engl J Med374:1932–1941, 2016. doi: 10.1056/NEJMoa1602003 4.Goldstein D, Moskowitz AJ, Gelijns AC, et al: Two-year outcomes of surgical treatment of severe ischemic mitral regurgitation.N Engl J Med374:344–353, 2016. doi: 10.1056/NEJMoa1512913 5.Feldman T, Kar S, Elmariah S, et al: Randomized comparison of percutaneous repair and surgery for mitral regurgitation: 5-year results of EVEREST II.J Am Coll Cardiol66:2844–2854, 2015. doi: 10.1016/j.jacc.2015.10.018 6.Obadia JF, Messika-Zeitoun D, Leurent G, et al: Percutaneous repair or medical treatment for secondary mitral regurgitation.N Engl J Med379:2297–2306, 2018. doi: 10.1056/NEJMoa1805374 7.Stone GW, Lindenfeld J, Abraham WT, et al: Transcatheter mitral-valve repair in patients with heart failure.N Engl J Med379:2307–2318, 2018. doi: 10.1056/NEJMoa1806640 