cardiovascular disorders
Mitral Stenosis
Treatment of Mitral Stenosis
Diuretics and sometimes beta-blockers or calcium channel blockers Sometimes anticoagulation for atrial fibrillation Commissurotomy or valve replacement Asymptomatic patients with mitral stenosis require no treatment other than appropriate Antibiotic prophylaxis recurrence. Surveillance with serial TTE is important, because RV enlargement and rise in RV systolic pressure can occur without patients noticing a change in functional state and without a decrease in mitral valve area. Early intervention may relieve pulmonary hypertension before it becomes permanent. Mildly symptomatic patients usually respond to diuretics and, if sinus tachycardia or atrial fibrillation is present, to beta-blockers or calcium channel blockers, which can control ventricular rate. Anticoagulation with a vitamin K antagonist (not a direct-acting oral anticoagulant [DOAC]) is indicated to prevent thromboembolism if patients have or have had atrial fibrillation, embolism, or a left atrial clot. Extended restoration of sinus rhythm is rarely possible. Anticoagulation may be considered in the presence of dense spontaneous contrast or an enlarged left atrium (M-mode diameter > 50 mm) because these findings are associated with thromboembolism, although anticoagulation for these patients has not been studied. All patients should be encouraged to continue at least low levels of physical exercise despite exertional dyspnea. Antibiotic prophylaxis against endocarditis is no longer recommended except for patients who have had valve replacement (see table). Moderate mitral stenosisintervention may be indicated when cardiac surgery is required for other indications. Patients who are symptomatic and have exercise-induced mean transmitral gradient > 15 mm Hg or pulmonary capillary occlusion pressure > 25 mm Hg may be considered for percutaneous balloon commissurotomy. Severe mitral stenosisintervention is indicated when any symptoms are present if the valve is suitable for percutaneous balloon commissurotomy (may be considered in asymptomatic patients if pulmonary pressure is > 50 mm Hg or there is new-onset atrial fibrillation). Cardiac surgery is pursued only when symptoms are severe and for patients who are not candidates for percutaneous balloon commissurotomy, require other cardiac operations, or do not have access to the percutaneous procedure. — Treatment reference ). In this fluoroscopic- and echocardiographic-guided procedure, a transvenous catheter with an inflatable distal balloon is passed transseptally from the right atrium to the LA and inflated to separate fused mitral valve commissures. Outcomes are equivalent to those of more invasive procedures. Complications are uncommon but include MR, embolism, and Surgical commissurotomymay be used in patients with severe subvalvular disease, valvular calcification, or LA thrombi. In this procedure, fused mitral valve leaflets are separated using a dilator passed through the left ventricle (closed commissurotomy) via a thoracotomy, or by direct vision (open commissurotomy) via a sternotomy. Choice of procedure is based on the surgeon’s experience and the morphology of the valve, although closed commissurotomy is done less frequently. Because of its greater risks, surgery is usually deferred until symptoms reach New York Heart Association class III (see table). During surgery, some clinicians ligate the left atrial appendage to reduce risk of thromboembolism. 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. When the etiology is annular calcification, there is no benefit from percutaneous balloon commissurotomy because there is no commissural fusion. Furthermore, surgical valve replacement is technically demanding because of the annular calcification and often high risk because many patients are older and have comorbidities. Therefore, intervention is delayed until symptoms become severe despite use of diuretic and rate control medications. Preliminary experience in patients who are not candidates for surgery suggests benefit from implantation of a transcatheter aortic valve replacement (TAVR) bioprosthesis in the mitral position. 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 