Dilated Cardiomyopathy

Background

• Dilated cardiomyopathy (DCM) is a spectrum of heterogeneous myocardial disorders characterized by left ventricular (LV) or biventricular dilation and systolic dysfunction in absence of coronary artery disease or abnormal loading conditions (such as hypertension or valvular heart disease) that can be due to various acquired and/or genetic causes.

Evaluation

• Suspect dilated cardiomyopathy in patients with unexplained heart failure signs and symptoms.
• Initial tests in patients with suspected dilated cardiomyopathy should follow recommendations for testing in patients with heart failure with reduced ejection fraction and includes
  • blood tests, such as complete blood count and serum chemistries
  • electrocardiogram (ECG)
  • cardiac imaging, including echocardiography and/or cardiac magnetic resonance imaging (MRI) to assess left ventricular size and function (cardiac MRI can also provide tissue characterization) and chest x-ray
• Rule out coronary artery disease in patients > 35 years old and in patients < 35 years old who have major coronary artery disease risk factors.
• Additional testing should be directed at suspected cause of dilated cardiomyopathy
  • Consider genetic testing for patients with family history of dilated cardiomyopathy, where family history includes 3 generations (patient, parents, grandparents).
  • Consider blood tests for patients with suspected rheumatoid arthritis, lupus, infection, or acromegaly.
  • Cardiac MRI is suggested in patients with suspected infiltrative cardiomyopathies (such as sarcoidosis or amyloidosis), congenital heart disease, myocarditis, or cardiac tumors.
  • Consider endomyocardial biopsy to evaluate for giant cell or fulminant myocarditis in patients with acute decompensated cardiomyopathy who require inotropic or mechanical circulatory support, Mobitz type II second-degree or higher-degree atrioventricular block, sustained or symptomatic ventricular tachycardia, or failure to respond to therapy within 1-2 weeks.

Management

• Use guideline-directed medical therapy for all patients with symptomatic heart failure with reduced ejection fraction that includes:
  • angiotensin-converting enzyme (ACE) inhibitors (or angiotensin receptor blockers [ARBs], or ARNI) and diuretics as needed (Strong recommendation)
  • beta blockers (such as carvedilol, metoprolol, or bisoprolol) (Strong recommendation)
  • see Heart Failure With Reduced Ejection Fraction (HFrEF) for details
• Treat the identified underlying causes of dilated cardiomyopathy (DCM) when possible.
• Consider the placement of an implantable cardioverter defibrillator (ICD) in selected patients, such as those with left ventricular ejection fraction (LVEF) ≤ 35% and symptomatic heart failure despite guideline-directed medical therapy.
• Consider cardiac resynchronization therapy (CRT) for selected patients with symptomatic heart failure, LVEF ≤ 35%, and a widened QRS (≥ 150 milliseconds), particularly with a left bundle branch block configuration.
• In patients with DCM and refractory symptoms of heart failure despite optimal medical and device management, consider mechanical circulatory support or selection for a cardiac transplantation.