Indications for Mitral Valve Repair in Mitral Regurgitation
Mitral valve repair is strongly indicated for symptomatic patients with severe primary mitral regurgitation and preserved left ventricular function (LVEF >30%), and for asymptomatic patients with severe primary mitral regurgitation who have developed left ventricular dysfunction (LVEF ≤60% and/or LVESD ≥40 mm). 1
Primary Mitral Regurgitation Indications
Symptomatic Patients
- Mitral valve repair for patients with severe primary MR who are symptomatic (NYHA class II-IV) with preserved LV function (LVEF >30%) (Class I recommendation) 1
- Surgery may be considered in symptomatic patients with severe primary MR and severe LV dysfunction (LVEF ≤30%) (Class IIb recommendation) 1
Asymptomatic Patients
- Mitral valve repair for asymptomatic patients with severe primary MR and LV dysfunction (LVEF ≤60% and/or LVESD ≥40 mm) (Class I recommendation) 1
- Mitral valve repair is reasonable in asymptomatic patients with severe primary MR and preserved LV function (LVEF >60% and LVESD <40 mm) when:
- There is >95% likelihood of successful repair with <1% mortality at a Heart Valve Center of Excellence (Class IIa) 1
- New onset of atrial fibrillation has occurred (Class IIa) 1
- Pulmonary hypertension is present (pulmonary artery systolic pressure >50 mmHg at rest) (Class IIa) 1
- Significant left atrial dilation is present (LA volume index ≥60 mL/m² or diameter >55 mm) (Class IIa) 1
Progressive Disease
- Mitral valve repair may be considered when there is progressive increase in LV size or decrease in EF on ≥3 serial imaging studies (Class IIb) 1
Secondary Mitral Regurgitation Indications
- Mitral valve surgery is reasonable for patients with chronic severe secondary MR who are undergoing CABG or AVR (Class IIa) 1
- For severe ischemic MR in severely symptomatic patients (NYHA III-IV) with persistent symptoms despite optimal GDMT:
Concomitant Surgery Indications
- Mitral valve repair or replacement is indicated in patients with chronic severe primary MR undergoing cardiac surgery for other indications (Class I) 1
- Mitral valve repair is reasonable in patients with chronic moderate primary MR (stage B) when undergoing cardiac surgery for other indications (Class IIa) 1
Repair vs. Replacement Considerations
- Mitral valve repair is strongly preferred over replacement when:
- In secondary MR, chordal-sparing MVR may be preferred over repair in severely symptomatic patients with chronic severe ischemic MR due to lower rates of MR recurrence 1
Timing Considerations
Early surgery should be considered before irreversible LV damage occurs. The most recent evidence suggests that surgery should be encouraged before:
- LVEF falls below 65%
- Left atrial volume index reaches 53 mL/m² or more 2
Procedural Success Factors
- Repair rates approaching 100% are achievable at specialized centers for degenerative mitral valve disease 3
- Favorable anatomic factors for successful repair include:
- Longer chordal length (>29 mm)
- Longer posterior leaflet length (>17 mm)
- Mitral annulus size >35 mm 4
- Unfavorable factors include anterior mitral annular calcification 4
Caveats and Pitfalls
- Waiting for symptoms to develop before referring for surgery may result in irreversible LV damage
- Repair of severely regurgitant valves should be performed at centers with high repair rates (>90%) and low operative mortality (<1%)
- Careful echocardiographic assessment is crucial to determine suitability for repair
- For secondary MR, addressing the underlying ventricular dysfunction is essential, as repair alone may have high failure rates 5
- Transcatheter mitral valve repair may be considered for severely symptomatic patients with prohibitive surgical risk 1
Mitral valve repair remains the gold standard treatment for primary MR with superior outcomes compared to replacement, preserving LV function and decreasing risks of thromboembolism and anticoagulation-related complications 6.