What are the indications for valve replacement in patients with mitral regurgitation (MR)?

Indications for Valve Replacement in Mitral Regurgitation

Mitral valve surgery is indicated for symptomatic patients with chronic severe primary mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) >30%, with valve repair preferred over replacement when feasible. 1

Primary Mitral Regurgitation

Class I Indications (Strong Recommendation)

1. Symptomatic patients with severe MR

   • Patients with LVEF >30% (Stage D) 1
   • Symptoms typically include decreased exercise tolerance and exertional dyspnea

2. Asymptomatic patients with LV dysfunction

   • LVEF 30-60% and/or LVESD ≥40 mm (Stage C2) 1
   • This represents early ventricular decompensation that warrants intervention before irreversible damage occurs

3. Severe MR in patients undergoing cardiac surgery for other indications 1

   • Concomitant repair or replacement is indicated

Class IIa Indications (Reasonable to Perform)

1. Asymptomatic patients with preserved LV function (Stage C1)
   • With new onset atrial fibrillation 1
   • With pulmonary hypertension (systolic pulmonary pressure >50 mmHg at rest) 1
   • When likelihood of successful repair is >95% with expected mortality <1% at a Heart Valve Center of Excellence 1

Class IIb Indications (May Be Considered)

1. Symptomatic patients with severe LV dysfunction

   • LVEF ≤30% (Stage D) 1
   • Note: This is a more challenging group with higher surgical risk

2. Asymptomatic patients with preserved LV function and:

   • Left atrial dilatation (volume index ≥60 ml/m²) and sinus rhythm 1
   • Pulmonary hypertension on exercise (SPAP ≥60 mmHg) 1

Secondary Mitral Regurgitation

1. Severe secondary MR in patients undergoing CABG with LVEF >30% 1

2. Symptomatic patients with severe secondary MR despite optimal medical therapy 1

   • After guideline-directed medical therapy (including CRT if indicated)
   • Heart team evaluation is crucial for these patients

Repair vs. Replacement Decision

Mitral valve repair is preferred over replacement when:

• Limited to posterior leaflet 1
• Involving anterior or both leaflets when durable repair is feasible 1
• In a center with high repair success rates

Replacement may be preferred when:

• Repair is unlikely to be durable
• Complex valve pathology exists
• Significant leaflet tethering or severely dilated annulus is present 1

Important Considerations

• Timing is critical: Early intervention before irreversible LV dysfunction develops improves outcomes

• Echocardiographic parameters defining severe MR include:

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

• Common pitfalls to avoid:

  1. Delaying surgery until symptoms develop in patients with LV dysfunction
  2. Underestimating MR severity with single measurements rather than integrating multiple parameters
  3. Attempting repair when replacement would be more durable
  4. Failing to recognize secondary MR, which has different treatment considerations than primary MR

Transcatheter Options

Transcatheter mitral valve repair (e.g., MitraClip) may be considered for:

• Severely symptomatic patients (NYHA class III-IV)
• With chronic severe primary MR
• Who have prohibitive surgical risk due to severe comorbidities
• With favorable anatomy for repair
• With reasonable life expectancy 1

The decision for mitral valve intervention should be made by a multidisciplinary heart team, weighing the risks and benefits of surgery versus medical management, especially in high-risk patients with significant comorbidities.