What are the indications for mitral valve replacement?

Indications for Mitral Valve Replacement

Mitral valve replacement is indicated for patients with severe mitral regurgitation who are symptomatic with LVEF >30% or asymptomatic with LV dysfunction (LVEF 30-60% and/or LVESD ≥40 mm), when mitral valve repair is not feasible or likely to be durable. 1

Primary Mitral Regurgitation

Class I Indications (Strong Recommendations)

• Symptomatic patients with severe primary MR (stage D) and LVEF >30% 1
• Asymptomatic patients with severe primary MR and LV dysfunction (LVEF 30-60% and/or LVESD ≥40 mm, stage C2) 1
• Patients with severe primary MR undergoing cardiac surgery for other indications 1

Class IIb Indications (May Be Considered)

• Symptomatic patients with severe primary MR and LVEF ≤30% (stage D) 1
• Patients with rheumatic mitral valve disease when repair is unlikely to be durable or when long-term anticoagulation management is questionable 1

Secondary Mitral Regurgitation

• Patients with severe secondary MR undergoing CABG and LVEF >30% 1
• Patients with severe secondary MR who remain symptomatic despite optimal medical therapy (including CRT if indicated) 1

Mitral Stenosis

• Symptomatic patients with clinically significant mitral stenosis (valve area ≤1.5 cm²) who are not suitable for percutaneous mitral commissurotomy (PMC) 1
• Patients with severe mitral stenosis and unfavorable valve anatomy for PMC 1, 2

Decision Algorithm for Mitral Valve Replacement vs. Repair

1. Assess valve pathology:

   • Repair is preferred for primary MR, especially when limited to posterior leaflet 1
   • Replacement is more appropriate for complex rheumatic disease, extensive calcification, or when repair is unlikely to be durable 3

2. Evaluate LV function:

   • LVEF >30%: Standard indications apply
   • LVEF ≤30%: Surgery may still be considered but with higher risk 1

3. Consider indexed LVESD:

   • ILVESD >19 mm/m² is associated with postoperative LV dysfunction 4
   • Early intervention before this threshold may preserve LV function

4. Assess pulmonary pressures:

   • Pulmonary artery systolic pressure >45 mmHg is associated with worse outcomes 4

Choice Between Mechanical vs. Bioprosthetic Valve

• Mechanical valve is recommended for:

  • Patients without contraindications to long-term anticoagulation 1
  • Patients at risk of accelerated structural valve deterioration 1

• Bioprosthetic valve is recommended for:

  • Patients with contraindications to anticoagulation or high bleeding risk 1
  • Patients with compliance issues for anticoagulation management 1
  • Reoperation for mechanical valve thrombosis despite good anticoagulant control 1

Important Considerations and Pitfalls

• Timing is critical: Delaying surgery until severe symptoms or LV dysfunction develops may result in irreversible myocardial damage 5

• Repair vs. replacement: While repair is generally preferred when feasible, replacement may be more appropriate in certain scenarios such as rheumatic disease, extensive calcification, or when durability of repair is questionable 1, 3

• Transcatheter options: For high-risk surgical patients, transcatheter mitral valve repair (e.g., MitraClip) may be considered for severe symptomatic primary MR (NYHA class III-IV) 1, 6

• Post-operative anticoagulation: Mechanical valves require lifelong anticoagulation with VKA; NOACs are contraindicated 1

• Center experience matters: Outcomes for mitral valve surgery are highly dependent on surgeon and center experience, particularly for repair procedures 1