What is the management plan for a patient with severe hypertrophic cardiomyopathy, significant mitral regurgitation, and coronary artery calcification?

Management of Severe Hypertrophic Cardiomyopathy with Significant Mitral Regurgitation

Surgical septal myectomy with evaluation of the mitral valve is strongly recommended for this patient with severe hypertrophic cardiomyopathy, significant mitral regurgitation, and coronary artery calcification. 1

Clinical Assessment and Findings

The patient presents with:

• Severe hypertrophic cardiomyopathy (HCM)
• Significant mitral regurgitation
• Coronary artery calcification (40% RCA, 30% diffuse LAD disease)
• Left ventricular systolic pressure of ~200 mmHg with aortic pressure of ~110 mmHg
• Significant gradient in the left ventricle
• Preserved LV function (EF 55%)
• Brockenbrough phenomenon (post-PVC beat)

Management Algorithm

1. Surgical Intervention

• Primary recommendation: Septal myectomy
  • Gold standard treatment for drug-refractory obstructive HCM 1
  • Directly addresses the septal hypertrophy causing LVOT obstruction
  • Typically results in resolution of mitral regurgitation by eliminating SAM
  • Low operative mortality (1-3%) in experienced centers 1

2. Mitral Valve Assessment and Management

• Intraoperative TEE is mandatory to assess mitral valve anatomy and function 1
• Decision algorithm for mitral valve:
  1. If MR is solely due to SAM: Myectomy alone is usually sufficient 2
  2. If intrinsic mitral valve abnormalities exist: Consider repair techniques 1
  3. If severe structural abnormalities present: Consider mitral valve replacement 3

3. Coronary Artery Management

• Coronary calcification with moderate stenosis (40% RCA, 30% LAD) should be evaluated
• Consider concomitant CABG if functionally significant stenoses are present 4

Evidence-Based Rationale

Septal myectomy is established as the most effective approach for reversing heart failure consequences by:

• Providing amelioration of obstruction at rest
• Relieving mitral regurgitation
• Restoring functional capacity and quality of life 1

The procedure works by:

• Basal septal thinning with enlargement of LVOT area
• Redirection of forward flow
• Elimination of SAM and mitral-septal contact
• Reduction of mitral regurgitation without additional valve surgery in most cases 1

Procedural Considerations

1. Surgical approach:

   • Transaortic septal myectomy (Morrow procedure) with 3-4 cm resection 1
   • Extended myectomy may be considered in some cases (7-8 cm resection) 1

2. Mitral valve assessment:

   • Intraoperative TEE is essential to guide the procedure 1
   • Assess for intrinsic mitral valve abnormalities vs. SAM-related MR

3. Operator experience:

   • Procedure should be performed at centers with significant experience
   • Recommended operator volume: at least 20 procedures or within an HCM program with cumulative volume of at least 50 procedures 1
   • Target mortality rate should be ≤1% with major complication rate ≤3% 1

Post-Procedure Management

• TTE within 3-6 months after the procedure to evaluate results 1
• Regular follow-up with TTE every 1-2 years to assess:
  • Degree of myocardial hypertrophy
  • Dynamic LVOTO
  • Mitral regurgitation
  • Myocardial function 1

Potential Pitfalls and Caveats

1. Inadequate myectomy: Most common cause of persistent symptoms - ensure adequate resection guided by intraoperative TEE 1

2. Overlooking intrinsic mitral valve disease: Careful assessment of mitral valve apparatus is crucial to determine if additional valve intervention is needed 1

3. Surgical expertise: Outcomes are highly dependent on surgical experience - refer to centers with extensive HCM surgical expertise 1

4. Complete heart block: A potential complication of septal myectomy - careful monitoring required 4

5. Ventricular septal defect: Rare but serious complication from excessive resection 4

This comprehensive approach addresses the patient's severe hypertrophic cardiomyopathy, significant mitral regurgitation, and coronary artery disease, with the primary goal of improving morbidity, mortality, and quality of life.