What is the management of mitral valve tenting with severe Mitral Regurgitation (MR)?

Management of Mitral Valve Tenting with Severe Mitral Regurgitation

Mitral valve tenting with severe mitral regurgitation (MR) requires surgical intervention with either mitral valve repair using a restrictive remodeling rigid annuloplasty ring or chord-sparing mitral valve replacement, depending on the degree of leaflet tethering and presence of left ventricular remodeling.

Understanding Mitral Valve Tenting

Mitral valve tenting is a characteristic feature of secondary (functional) MR, where:

• The mitral leaflets are structurally normal but fail to coapt properly due to left ventricular remodeling
• Tenting occurs when the papillary muscles are displaced due to left ventricular dilation, pulling the chordae tendineae and restricting leaflet mobility
• This creates a tented appearance of the valve with increased distance between the annular plane and coaptation point

Diagnostic Assessment

Echocardiographic Criteria for Severe Secondary MR:

• Vena contracta ≥7 mm 1
• Effective regurgitant orifice area (EROA) ≥0.2-0.4 cm² 1
• Regurgitant volume ≥30-60 mL/beat 1
• Regurgitant fraction ≥50% 1
• Pulmonary vein systolic flow reversal 1

Key Measurements:

• Tenting height >10 mm indicates severe leaflet tethering 1
• Left ventricular ejection fraction (LVEF)
• Left ventricular dimensions
• Presence of inferobasal aneurysm

Management Algorithm

1. Medical Therapy (First-Line)

• Optimize guideline-directed medical therapy (GDMT) for heart failure 1:
  • ACE inhibitors/ARBs
  • Beta-blockers
  • Mineralocorticoid receptor antagonists (MRAs)
  • SGLT2 inhibitors
  • Consider sacubitril/valsartan
• Cardiac resynchronization therapy (CRT) if indicated 1, 2
• Reassess MR severity after optimization of medical therapy 1

2. Surgical Intervention Indications

• For patients with severe secondary MR undergoing CABG and LVEF >30%: Mitral valve surgery is indicated (Class I, Level C) 1
• For symptomatic patients despite optimal medical therapy (including CRT if indicated) with LVEF >30%: Consider mitral valve surgery if low surgical risk 1
• For patients with severe secondary MR, LVEF ≤30% who have indication for CABG: Mitral valve surgery may be considered (Class IIb) 1

3. Surgical Approach Selection

A. Mitral Valve Repair:

• Preferred for: Patients with annular dilation mechanism without severe leaflet tethering 1
• Technique: Restrictive remodeling rigid annuloplasty ring 1
• Additional procedures may include:
  • Secondary or tertiary chordal cutting
  • Papillary muscle sling
• Avoid as sole therapy in setting of Carpentier Type IIIB mechanism with left ventricular inferobasal aneurysm 1

B. Chord-Sparing Mitral Valve Replacement:

• Preferred for: 1
  • Severe leaflet tethering (tenting height >10 mm)
  • Presence of inferobasal aneurysm
  • Reasonable to consider over repair for severe ischemic MR

4. Percutaneous Options

• For high-risk surgical patients: Transcatheter edge-to-edge repair (TEER) should be considered in patients with: 1
  • LVEF >30% and severe MR
  • No indication for coronary revascularization
  • Persistent symptoms despite optimal GDMT (including CRT if indicated)
  • Favorable valve anatomy for the procedure
  • Life expectancy >1 year

Monitoring and Follow-up

• Echocardiography prior to discharge or within 1-3 months after intervention 1
• For patients with severe MR managed medically: clinical follow-up every 6 months and echocardiography annually 1

Important Considerations and Pitfalls

• Dynamic nature of MR: Secondary MR can vary with loading conditions; consider exercise echocardiography to assess dynamic changes 1
• Surgical outcomes: Mitral valve repair for secondary MR has higher recurrence rates than for primary MR 1
• Surgical expertise: Outcomes of mitral valve repair depend on surgeon experience and center volume 1
• Inadequate medical optimization: Ensure optimal medical therapy before considering intervention 2
• Surgical risk assessment: Use validated risk scores (STS-PROM) and consider frailty and comorbidities 1

By following this structured approach to the management of mitral valve tenting with severe MR, clinicians can optimize outcomes for this challenging patient population.