What is the recommended treatment for severe mitral valve disease?

Treatment of Severe Mitral Valve Disease

For severe mitral valve disease, surgical intervention is recommended, with mitral valve repair preferred over replacement whenever feasible, particularly for primary mitral regurgitation with preserved left ventricular function. 1

Classification and Assessment

Mitral valve disease is classified based on:

1. Etiology: Primary (valve pathology) vs. Secondary (ventricular dysfunction)
2. Severity: Stages A through D
3. Symptoms: Asymptomatic vs. Symptomatic
4. Left ventricular function: Preserved vs. Reduced

Primary Mitral Regurgitation (MR)

Primary MR involves structural abnormalities of the valve components:

• Mitral valve prolapse with loss of coaptation
• Rheumatic changes with leaflet restriction
• Prior infective endocarditis
• Radiation-induced thickening

Severe MR is defined by:

• Central jet >40% of left atrium
• Vena contracta ≥0.7 cm
• Regurgitant volume ≥60 mL
• Regurgitant fraction ≥50%
• Effective regurgitant orifice (ERO) ≥0.40 cm² 1

Secondary MR

Secondary MR results from left ventricular dysfunction causing:

• Tethering of mitral leaflets
• Annular dilation with loss of coaptation

Severe secondary MR is defined by:

• ERO ≥0.20 cm²
• Regurgitant volume ≥30 mL
• Regurgitant fraction ≥50% 1

Treatment Algorithm for Severe Mitral Valve Disease

1. Primary Mitral Regurgitation

Symptomatic Patients (Stage D):

• LVEF >30%: Mitral valve surgery (Class I recommendation) 1
• LVEF ≤30%: Mitral valve surgery may be considered (Class IIb) 1
• High surgical risk: Transcatheter mitral valve repair may be considered for severely symptomatic patients (NYHA class III-IV) with favorable anatomy 1

Asymptomatic Patients:

• With LV dysfunction (LVEF 30-60% and/or LVESD ≥40 mm, Stage C2): Mitral valve surgery (Class I recommendation) 1
• With preserved LV function (Stage C1):
  • Mitral valve repair is reasonable when likelihood of successful repair >95% with mortality <1% at a Heart Valve Center of Excellence (Class IIa) 1
  • Mitral valve repair is reasonable with new-onset atrial fibrillation or pulmonary hypertension (Class IIa) 1

2. Secondary Mitral Regurgitation

• Optimize guideline-directed medical therapy (GDMT) first
• If symptoms persist despite optimal GDMT:
  • Low surgical risk: Consider mitral valve surgery (Class IIb) 1
  • High surgical risk with appropriate anatomy: Consider transcatheter edge-to-edge repair (TEER) (Class IIa) 1

Surgical Approach

Mitral Valve Repair vs. Replacement

• Mitral valve repair is strongly preferred over replacement when:

  • Primary MR is limited to the posterior leaflet (Class I) 1
  • Primary MR involves anterior or both leaflets when durable repair is feasible (Class I) 1
  • Rheumatic valve disease when durable repair is likely (Class IIb) 1

• Mitral valve replacement may be necessary when:

  • Repair is not feasible
  • Complex pathology exists
  • Extensive calcification is present

Concomitant Procedures

• Mitral valve repair/replacement is indicated during cardiac surgery for other indications if severe MR is present (Class I) 1
• Concomitant repair is reasonable for moderate MR during cardiac surgery for other indications (Class IIa) 1

Special Considerations

1. Timing of intervention: Early intervention before irreversible ventricular damage occurs improves outcomes 2

2. Expertise matters: Outcomes are superior at Heart Valve Centers of Excellence with high repair rates and low mortality 1, 3

3. Follow-up: Regular echocardiographic monitoring is essential for asymptomatic patients with severe MR

4. Transcatheter options: Expanding role for high-risk surgical patients, with ongoing clinical trials evaluating efficacy 4

Pitfalls to Avoid

1. Delayed referral: Waiting until symptoms are severe or LV dysfunction develops can lead to irreversible damage and worse outcomes

2. Underestimating severity: Relying on a single parameter rather than comprehensive assessment can lead to misclassification

3. Inadequate surgical expertise: Attempting complex repairs at low-volume centers may result in suboptimal outcomes

4. Ignoring secondary MR mechanism: Treating the valve without addressing ventricular dysfunction may lead to recurrent MR

5. Overlooking comorbidities: Failing to consider patient's overall condition and surgical risk can lead to inappropriate intervention choices

By following this evidence-based approach, clinicians can optimize outcomes for patients with severe mitral valve disease, reducing mortality and improving quality of life through appropriate timing and selection of interventions.