What is the difference in managing tricuspid regurgitation (TR) in patients with mitral stenosis (MS) versus atrial septal defect (ASD)?

Management of Tricuspid Regurgitation in Mitral Stenosis vs. ASD

Tricuspid regurgitation (TR) management differs significantly between mitral stenosis (MS) and atrial septal defect (ASD) patients, with MS patients typically requiring more aggressive surgical intervention while ASD patients often experience spontaneous TR improvement after defect closure alone.

Pathophysiology and Mechanisms

Mitral Stenosis-Associated TR

• TR in MS is typically functional, secondary to:
  • Pulmonary hypertension from left atrial pressure elevation
  • Right ventricular (RV) pressure overload and remodeling
  • Tricuspid annular dilation
  • Often associated with atrial fibrillation 1
• May have concurrent rheumatic involvement of tricuspid valve

ASD-Associated TR

• TR in ASD is primarily due to:
  • RV volume overload from left-to-right shunt
  • Tricuspid annular dilation
  • Functional TR without structural valve disease 2

Diagnostic Approach

Mitral Stenosis

• Comprehensive echocardiography to assess:
  • MS severity (valve area, gradients)
  • TR severity and mechanism
  • Pulmonary artery pressures
  • RV size and function
  • Tricuspid annular diameter (significant if ≥40 mm or >21 mm/m²) 3

ASD

• Echocardiography to evaluate:
  • ASD size and shunt volume
  • TR severity
  • RV dilation
  • Tricuspid annular dimensions
  • Coaptation distance and systolic tenting area 2

Management Approaches

Mitral Stenosis with TR

1. Surgical Management:

   • Combined mitral valve surgery with tricuspid valve repair is recommended for patients with severe MS and severe TR 3, 4
   • Tricuspid annuloplasty with prosthetic rings is preferred over flexible bands 5
   • Tricuspid valve surgery is indicated when TR is severe and associated with symptoms or progressive RV dilation 3, 5

2. Percutaneous Approach:

   • Percutaneous mitral balloon valvuloplasty (PMBC) can be considered in selected patients with:
     • Favorable mitral valve anatomy (echo score ≤8)
     • Sinus rhythm
     • Moderate atrial enlargement
     • Functional TR secondary to pulmonary hypertension 3
   • However, PMBC alone has lower rates of TR improvement (46%) compared to surgical approach (98%) 4

3. Predictors of TR Resolution After PMBC:

   • Smaller initial TR jet area
   • Greater reduction in transmitral pressure gradient
   • Successful long-term PMBC result 6
   • TR resolution is unlikely with unsuccessful PMBC (only 6.7% resolution) 6

ASD with TR

1. Primary Management:

   • ASD closure alone (surgical or transcatheter) without tricuspid valve intervention is typically sufficient 2
   • Significant reduction in TR severity occurs in most patients after ASD closure, even without tricuspid valve surgery 2

2. Post-Closure Outcomes:

   • TR severity decreases from moderate/severe to mild in most patients
   • Significant reductions in:
     • Tricuspid valve annular diameter
     • Coaptation distance
     • Systolic tenting area 2

3. Predictors of Residual TR After ASD Closure:

   • Right atrial area is the strongest predictor of residual TR 2

Decision Algorithm for TR Management

For Mitral Stenosis Patients:

1. If severe MS with severe TR:

   • First choice: Combined mitral valve surgery with tricuspid valve repair, especially with:
     • Atrial fibrillation
     • RV enlargement
     • Tricuspid annular dilation ≥40 mm
     • Organic tricuspid valve disease 3, 4

2. If severe MS with moderate TR:

   • Perform tricuspid annuloplasty at time of mitral valve surgery 5

3. If severe MS with severe functional TR and favorable valve anatomy:

   • Consider PMBC only if:
     • Young patient
     • Sinus rhythm
     • Severe pulmonary hypertension
     • No significant RV enlargement 7, 6

For ASD Patients:

1. If ASD with moderate/severe TR:

   • Proceed with ASD closure alone (surgical or transcatheter)
   • Observe for TR regression over 6-12 months 2

2. If ASD with severe TR and very large tricuspid annulus:

   • Consider ASD closure with concomitant tricuspid valve repair only if:
     • Severe RV enlargement
     • Very large right atrium
     • Organic tricuspid valve disease 2

Clinical Pearls and Pitfalls

Important Considerations:

• TR in MS often persists or worsens after isolated mitral intervention if not addressed surgically 1
• TR in ASD typically improves spontaneously after defect closure 2
• Delaying tricuspid valve surgery in MS can lead to irreversible RV dysfunction 5
• Severe RV dysfunction is a contraindication for isolated tricuspid valve surgery 5

Monitoring After Intervention:

• Regular echocardiographic surveillance is essential to assess:
  • TR severity
  • RV size and function
  • Pulmonary artery pressures 5
• Earlier intervention is preferred before development of RV dysfunction 1