What is the workup for non-ischemic cardiomyopathy (dilated cardiomyopathy)?

From the Guidelines

The workup of non-ischemic cardiomyopathy should begin with a comprehensive history, physical examination, and basic laboratory tests, followed by cardiac imaging with echocardiography as the initial imaging modality, and may include cardiac MRI with or without IV contrast for tissue characterization and risk stratification, as recommended by the most recent guidelines 1. The initial evaluation should include a 12-lead ECG, chest X-ray, complete blood count, comprehensive metabolic panel, thyroid function tests, and cardiac biomarkers (troponin, BNP).

• Echocardiography is essential to assess cardiac structure, function, and ejection fraction, and provides information on morphology and function.
• Cardiac MRI with or without IV contrast may also be used to provide information on morphology and function, and is particularly useful for tissue characterization and risk stratification. Some key points to consider in the workup of non-ischemic cardiomyopathy include:
• The use of imaging techniques to answer specific clinical questions, rather than performing all techniques on every patient 1.
• The importance of excluding coronary artery disease, especially in patients with risk factors, using modalities such as cardiac computed tomography (CT) or coronary angiography 1.
• The role of genetic testing in patients with familial history of cardiomyopathy or sudden cardiac death.
• The potential use of endomyocardial biopsy in specific situations, such as suspected myocarditis or infiltrative diseases. Additional specialized tests may include exercise stress testing to assess functional capacity, Holter monitoring for arrhythmia detection, and screening for systemic diseases that can cause cardiomyopathy (hemochromatosis, sarcoidosis) 1. This comprehensive approach helps identify the underlying cause, which is crucial for determining appropriate treatment strategies and providing prognostic information to patients with non-ischemic cardiomyopathy.

From the Research

Diagnostic Approach

• The workup of non-ischemic cardiomyopathy involves a comprehensive diagnostic approach, including clinical evaluation, electrocardiogram (ECG), echocardiography, and cardiac magnetic resonance (CMR) imaging 2.
• CMR imaging is considered the gold standard for noninvasive assessment of cardiac morphology, function, and myocardial tissue changes 2.
• The diagnostic workup should also include laboratory tests, such as complete blood count, erythrocyte sedimentation rate, and troponin levels, to identify potential underlying causes of non-ischemic cardiomyopathy 3.

Role of Cardiac Resynchronization Therapy

• Cardiac resynchronization therapy (CRT) is a useful therapeutic option for patients with symptomatic heart failure and non-ischemic cardiomyopathy, with benefits including improved symptoms, quality of life, and survival 4, 5.
• CRT is recommended for patients with left ventricular ejection fraction (LVEF) ≤35% and QRS duration ≥130 ms, regardless of the etiology of heart failure 5.
• However, the response to CRT can vary, and multimodality imaging, including CMR and nuclear imaging, may help refine the selection criteria and optimize the implant technique 4.

Management and Treatment

• The management of non-ischemic cardiomyopathy involves a multidisciplinary approach, including medical therapy, device therapy, and heart failure management 6.
• The treatment should be individualized based on the underlying cause and severity of the disease, as well as the presence of comorbidities and other factors 6.
• Immunologic workup and cardiac MRI can play a crucial role in etiologic diagnosis and outcomes in patients with non-ischemic cardiomyopathy 3.

Imaging Techniques

• CMR imaging can detect early and typical signs of ongoing myocardial remodeling in patients presenting with a 'hot phase' non-ischemic cardiomyopathy, including myocardial edema, perfusion abnormalities, and pathological mapping values 2.
• CMR imaging can also help differentiate non-ischemic cardiomyopathy from other acute heart conditions, such as acute coronary syndromes, takotsubo syndrome, myocarditis, pericarditis, and sarcoidosis 2.