Management of Restrictive Cardiomyopathy
The management of restrictive cardiomyopathy is primarily palliative, focusing on treating heart failure symptoms with diuretics and heart rate control to optimize left ventricular filling, while anticoagulation should be used in all patients with atrial fibrillation. 1
General Approach to Management
- Restrictive cardiomyopathy (RCM) has the worst prognosis among all cardiomyopathy phenotypes, with limited treatment options that are often ineffective 1, 2
- Management must account for RCM's unique physiology: fixed stroke volume, cardiac output dependent on heart rate, and poor tolerance to beta-blockers due to their negative chronotropic and inotropic effects 1
- Treatment should be tailored based on the underlying etiology, as disease-specific therapies may be available for certain causes (e.g., cardiac amyloidosis, hemochromatosis) 2, 3
Heart Failure Management
- Diuretics are the mainstay of treatment to reduce venous and systemic congestion, but must be used cautiously as they may reduce stroke volume and cardiac output 2
- Heart rate control is essential to optimize left ventricular filling, particularly in patients with atrial fibrillation 1
- Beta-blockers and calcium channel blockers should be used with caution as they may not be well tolerated due to their negative chronotropic effects in RCM 1, 2
- Angiotensin-converting enzyme inhibitors are generally ineffective in RCM 2
Arrhythmia Management
- Atrial fibrillation is common in RCM (prevalence 45-51%, annual incidence 4-10%) and requires appropriate management 1
- Anticoagulation should be used in all patients with AF regardless of CHA₂DS₂-VASc score due to high risk of thromboembolism 1
- In cardiac amyloidosis specifically, anticoagulation should be considered even in sinus rhythm due to amyloid infiltration causing diminished atrial contractility and increased risk of thrombus formation 1
- For rhythm control in hemodynamically unstable patients, direct current cardioversion or amiodarone IV infusion is preferred 1
Device Therapy
- An ICD is recommended (Class I recommendation) in patients with restrictive cardiomyopathy and sustained ventricular arrhythmias causing hemodynamic instability who are expected to survive >1 year with good functional status 1
- For patients with cardiac amyloidosis specifically, an ICD should be considered (Class IIa recommendation) if they have ventricular arrhythmias causing hemodynamic instability and life expectancy >1 year with good functional status 1
- Primary prevention ICD implantation should be determined by the underlying etiology and established risk factors for sudden cardiac death 1
Disease-Specific Therapies
- Targeted therapy directed at specific causes may be more effective than symptomatic treatment 2, 3:
- Somatostatin analogues for carcinoid syndrome
- Iron chelation with desferrioxamine in hemochromatosis
- Disease-modifying treatments for cardiac amyloidosis
Advanced Therapies
- Cardiac transplantation may be considered in appropriate candidates with end-stage disease 2
- Autologous stem cell transplant has shown benefit in some cases of amyloidosis 2
Monitoring and Follow-up
- Regular assessment of NYHA functional class, left atrial size, and ventricular function is important as these are risk factors for mortality 1
- In children with RCM, closer monitoring may be warranted due to potentially higher risk of sudden death, particularly in those with ECG evidence of myocardial ischemia 1
Important Considerations and Pitfalls
- Differentiation from constrictive pericarditis is crucial, as constriction may be effectively treated by surgical removal of the thickened pericardium 2
- Comprehensive evaluation for underlying systemic diseases is essential as RCM may be a manifestation of treatable conditions 4
- Early detection and aggressive management are key to maintaining optimal patient function for as long as possible 2
- Avoid excessive diuresis which can lead to hypotension due to the fixed stroke volume in RCM 1, 2