Mitral Stenosis Treatment & Management

The goal of medical treatment for mitral stenosis is to reduce recurrence of rheumatic fever, provide prophylaxis for infective endocarditis, reduce symptoms of pulmonary congestion (eg, orthopnea, paroxysmal nocturnal dyspnea), control the ventricular rate if atrial fibrillation is present, and prevent thromboembolic complications.

• Because rheumatic fever is the primary cause of mitral stenosis, secondary prophylaxis against group A beta-hemolytic streptococci (GAS) is recommended.^[3] Duration of prophylaxis depends on the number of previous attacks, the time elapsed since the last attack, the risk of exposure to GAS infections, the age of the patient, and the presence or absence of cardiac involvement. Penicillin is the agent of choice for secondary prophylaxis, but sulfadiazine or a macrolide or azalide are acceptable alternatives in individuals allergic to penicillin (Tables 1 and 2).
• A recent study done in Europe on 315 patients with rheumatic mitral stenosis showed a significantly slower progression of rheumatic mitral stenosis in patients treated with statins compared with patients not taking statins. These findings could have an important impact in the early medical therapy of patients with rheumatic heart disease.^[4]
• The current American Heart Association (AHA) recommendations^[5] no longer suggest infective endocarditis prophylaxis for patients with rheumatic heart disease. However, the maintenance of optimal oral health care remains an important component of an overall healthcare program. For the relatively few patients with rheumatic heart disease in whom infective endocarditis prophylaxis remains recommended, such as those with prosthetic valves or prosthetic material used in valve repair, the current AHA recommendations should be followed. These recommendations advise the use of an agent other than a penicillin to prevent infective endocarditis in those receiving penicillin prophylaxis for rheumatic fever because oral alpha-hemolytic streptococci are likely to have developed resistance to penicillin.
• Initial symptoms of pulmonary congestion can be safely treated by diuretics. Dietary sodium restriction and nitrates decrease preload and can be of additional benefit. Careful use of beta-blockers in patients with a normal sinus rhythm can prolong the diastolic filling time and thus decrease in left atrial pressure. In general, afterload reduction should be avoided as it can cause hypotension.
• Atrial fibrillation is common in mitral stenosis and often leads to a rapid ventricular rate with reduced diastolic filling time and increased left atrial pressure. The ventricular rate can be slowed acutely by the administration of intravenous beta-blocker or calcium channel blocker therapy (diltiazem or verapamil). The rate and/or rhythm can be controlled long-term with oral beta-blockers, calcium channel blockers, amiodarone, or digoxin.
• In the patient with mild mitral stenosis and recent-onset (< 6 mo) atrial fibrillation, conversion to sinus rhythm can be accomplished with pharmacologic agents or electrical cardioversion. In this circumstance, anticoagulation therapy should be given for at least 3 weeks prior to cardioversion. Alternatively, a TEE can be performed to exclude the presence of left atrial thrombus, prior to cardioversion. Patients who are successfully converted to sinus rhythm should receive long-term anticoagulation and antiarrhythmic drugs.
• Surgical correction of the mitral stenosis is indicated if embolization is recurrent, despite adequate anticoagulation therapy.

Table 1. Duration of Secondary Rheumatic Fever Prophylaxis (Open Table in a new window)

Table 2. Secondary Prevention of Rheumatic Fever (Prevention of Recurrent Attacks) (Open Table in a new window)

Surgical therapy for mitral stenosis consists of mitral valvotomy (which can be either surgical or percutaneous) or mitral valve replacement. The surgical mitral valvotomy approach can be through an open or closed technique; the latter technique is rarely used, except in developing countries, and has largely been replaced by the percutaneous balloon valvotomy.^[2]

Asymptomatic patients with moderate or severe mitral stenosis (mitral valve area < 1.5 cm²) and a suitable valve should be considered for percutaneous balloon valvuloplasty if the pulmonary arterial systolic pressure is ≥ 50 mm Hg at rest or ≥ 60 mm Hg with exercise, or pulmonary capillary wedge pressure is ≥ 25 mm Hg with exercise.^[6]

Symptomatic patients with moderate or severe mitral stenosis (mitral valve area < 1.5 cm²) and suitable valve are also candidates for percutaneous balloon valvuloplasty.

If percutaneous balloon valvuloplasty is not an option, patients should be referred for surgical repair or mitral valve replacement.

• Percutaneous balloon valvuloplasty

  • Percutaneous balloon valvuloplasty is the procedure of choice for patients with uncomplicated mitral stenosis. Patients with pliable, mobile, relatively thin, minimally calcified mitral leaflets with minimal or no subvalvular stenosis are good candidates for this procedure. A TEE should be performed prior to valvotomy to clearly define the valve anatomy and exclude the presence of a left atrial thrombus.
  • The echocardiographic scoring system (Wilkins score) has been used as a valuable tool for patient selection. Leaflet mobility, valvular thickening, valvular calcification, and subvalvular disease are each given a score of 0-4, with higher scores indicating more severe involvement. A total score of less than 8 results in good short- and long-term outcome with balloon valvuloplasty.
  • With percutaneous balloon valvuloplasty, a catheter is directed into the left atrium after transseptal puncture, and a balloon is directed across the valve and inflated in the orifice. This results in separation of the mitral leaflets. The valve size can be increased up to 2-2.5 cm².
  • Improvement in symptoms is noted immediately following the procedure. If symptoms do not improve, the valvuloplasty was either ineffective or resulted in mitral regurgitation.
  • The short- and long-term prognoses are favorable compared with surgical valvotomy.
  • Balloon valvuloplasty offers certain advantages over surgical valvotomy, including avoidance of a thoracotomy and general anesthesia and their attendant complications.
  • The major contraindications to balloon valvuloplasty are the presence of thrombus in the left atrium or its appendage, moderate-to-severe mitral regurgitation, and an unfavorable valve morphology (ie, high Wilkins echo score).
  • Complications of a balloon mitral valvuloplasty include embolization, mitral regurgitation, ventricular rupture, residual atrial septal defect, stroke, and death.
• Surgical valvotomy/valve replacement^[7]

  • Open surgical commissurotomy allows direct visualization of the mitral valve.
  • Using current techniques, even severe regurgitant or stenotic valves can often be repaired, with good long-term results. Valves that are not suitable for repair can be replaced using either bioprosthetic or metallic prosthetic valves.
  • With bioprosthetic valves, the patient does not require anticoagulation, as long as he or she remains in sinus rhythm; however, 20-40% of these valves fail within 10 years, secondary to structural deterioration.
  • Mechanical valves are placed in young patients who do not have any contraindications for anticoagulation, and these valves are associated with good long-term durability.
  • Patients who have chronic atrial fibrillation and who undergo mitral valve surgery can have simultaneous Cox Maze procedure or pulmonary vein ablation, which helps to maintain sinus rhythm in up to 80% of the cases during the postoperative period.

A cardiology and/or cardiothoracic surgery consult may be necessary.

The patient should start a low-salt diet if pulmonary vascular congestion is present.

In most patients with mitral stenosis, recommendations for exercise are symptom limited. Patients should be encouraged to pursue a low-level aerobic exercise program for maintenance of cardiovascular fitness.