What is the management of cardiomyopathy?

Management of Cardiomyopathy

The management of cardiomyopathy requires a coordinated multidisciplinary approach with referral to specialized cardiomyopathy centers for optimal outcomes, particularly for complex treatment decisions and invasive procedures specific to cardiomyopathy patients. 1

Types of Cardiomyopathy and Initial Approach

Cardiomyopathies represent a heterogeneous group of diseases affecting heart muscle structure and function, classified as:

• Dilated cardiomyopathy (DCM) - characterized by ventricular dilation and systolic dysfunction
• Hypertrophic cardiomyopathy (HCM) - characterized by ventricular wall thickening
• Restrictive cardiomyopathy (RCM) - characterized by impaired ventricular filling
• Arrhythmogenic cardiomyopathy - characterized by fibrofatty replacement of myocardium

Diagnostic Evaluation

1. Cardiac imaging:

   • Echocardiography is the foundational imaging modality
   • Cardiovascular magnetic resonance imaging for diagnostic uncertainty, poor echo windows, or ICD placement decisions 1

2. Laboratory testing:

   • B-type natriuretic peptide (BNP) levels (levels >300 pg/mL predict poor outcomes in children) 2
   • Baseline serum chemistries

3. Electrical assessment:

   • Electrocardiography
   • Consider ambulatory monitoring for arrhythmia detection, particularly for AF risk assessment 1

4. Genetic evaluation:

   • Family history assessment
   • Genetic testing and counseling, particularly for HCM 1
   • Pathogenicity of detected variants should be reconfirmed every 2-3 years 1

Treatment Approaches by Cardiomyopathy Type

Hypertrophic Cardiomyopathy (HCM)

1. Pharmacologic therapy:

   • First-line: Beta-blockers, non-dihydropyridine calcium channel blockers
   • Second-line: Disopyramide for obstructive HCM
   • Newer agents: Cardiac myosin inhibitors (mavacamten) for symptomatic obstructive HCM not responding to first-line therapy 1

2. Septal reduction therapies for drug-refractory or severe outflow tract obstruction:

   • Surgical septal myectomy
   • Alcohol septal ablation
   • Should be performed at experienced HCM centers 1

3. ICD placement for sudden cardiac death prevention based on:

   • Risk marker assessment (apical aneurysm, decreased LV function, extensive gadolinium enhancement)
   • Risk score calculation
   • Patient's risk tolerance and treatment goals 1

Dilated Cardiomyopathy (DCM)

1. Standard heart failure therapy:

   • ACE inhibitors/ARBs
   • Beta-blockers
   • Mineralocorticoid receptor antagonists
   • SGLT2 inhibitors
   • Diuretics for congestion 1, 2

2. Advanced therapies for refractory cases:

   • Cardiac resynchronization therapy
   • Left ventricular assist devices
   • Heart transplantation 1

3. Special considerations:

   • Immunomodulatory therapy may be considered in inflammatory DCM
   • Avoid steroids in pediatric myocarditis 1

Restrictive Cardiomyopathy (RCM)

1. Medical management:

   • Cautious use of beta-blockers (may not be tolerated due to fixed stroke volume) 1
   • Diuretics for congestion
   • Treatment of underlying cause when identified

2. Advanced therapies:

   • Early consideration of heart transplantation due to poor prognosis 1

Management of Specific Complications

Atrial Fibrillation

1. Anticoagulation:

   • Direct oral anticoagulants (or warfarin) recommended for all cardiomyopathy patients with AF regardless of CHA₂DS₂-VASc score 1
   • Left atrial appendage closure for patients with high bleeding risk 1

2. Rhythm control:

   • For HCM: Sotalol and amiodarone preferred (amiodarone more effective but more side effects) 1
   • Cardioversion for hemodynamically unstable patients 1

Heart Failure Management

1. Pediatric considerations:

   • Standard therapy includes diuretics, ACE inhibitors, beta-blockers, and digoxin 2
   • Mechanical assist devices and heart transplantation for severe cases 2
   • Regular monitoring of growth and ventricular function 2

2. Advanced heart failure:

   • EF <50% in HCM indicates significantly impaired function and poor prognosis 1
   • Consider advanced therapies early in progressive disease 1

Care Coordination and Follow-up

1. Multidisciplinary approach:

   • Referral to specialized cardiomyopathy centers for complex decisions 1
   • Coordination between specialists (cardiology, genetics, rheumatology, etc.) 1

2. Lifestyle modifications:

   • Moderate exercise is beneficial and not associated with increased arrhythmia risk 1
   • Sodium restriction
   • Weight management
   • Smoking cessation

3. Family screening:

   • First-degree relatives should be screened using genetic testing or serial imaging 1
   • Can begin at any age based on patient/family history and preference 1

Pitfalls and Caveats

• Avoid anti-inflammatory therapy with steroids in pediatric myocarditis 1
• Recognize that an EF <50% in HCM indicates significantly impaired function (unlike in general population) 1
• Consider that children may not readily describe symptoms, making routine exercise testing particularly important 1
• Remember that RCM patients may not tolerate beta-blockers due to fixed stroke volume and heart rate dependence 1
• Understand that septal reduction therapies should only be performed at experienced centers to minimize complications 1