NICM: Nonischemic Cardiomyopathy
NICM stands for Nonischemic Cardiomyopathy (or Nonischemic Cardiomyopathies). 1
Definition and Scope
Nonischemic cardiomyopathies encompass a broad spectrum of myocardial disorders characterized by mechanical or electrical dysfunction leading to inappropriate ventricular hypertrophy or dilation, occurring without evidence of ischemia. 1
- The myocardial involvement can be either primary (genetic, acquired, or mixed) or secondary to a systemic disease process 1
- Valvular, hypertensive, and congenital diseases are typically treated separately from NICM 1
Classification of NICM
The five main morphological and functional variants include: 1
- Hypertrophic cardiomyopathy (HCM)
- Restrictive cardiomyopathy or infiltrative diseases
- Dilated cardiomyopathy (DCM) or unclassified cardiomyopathy
- Arrhythmogenic cardiomyopathy (arrhythmia of ventricular origin)
- Inflammatory cardiomyopathy
Each variant can be further subclassified as familial or nonfamilial types 1
Epidemiology and Clinical Significance
- NICM has an approximate prevalence of 0.02% with an annual death rate of 25,000 in the United States 1
- In adults, the prevalence of HCM is 1:250 to 500, DCM is 1:250 to 500, and arrhythmogenic right ventricular cardiomyopathy is 1:2,000 to 5,000 1
- In patients with clinical heart failure, a primary cardiomyopathy is diagnosed in 2% to 15% of patients 1
Clinical Presentation
Common presentations include: 1
- Dyspnea, edema, and ascites
- Chest discomfort and palpitations
- Syncope
- Heart failure, arrhythmia, sudden death, and acute chest pain
Unlike ischemic cardiomyopathy, the pathophysiology of NICM is usually unclear and multifactorial, the functional consequences are global, the prognosis is better, and the therapeutic response is different 1