The Exchange

Commentary and Observations from
the Medical Front Lines

An Overview of Non-Compaction Cardiomyopathy

An Overview of Non-Compaction Cardiomyopathy

Non-compaction cardiomyopathy (NCCM) carries a significant risk of malignant arrhythmias, thromboembolic events, and left ventricular dysfunction. This post provides an overview of the characteristics, diagnosis, and management of this type of cardiomyopathy.

What is NCCM?

NCCM is characterized by the existence of prominent and significant myocardial trabeculations; it has also been referred to as spongy myocardium, spongiform cardiomyopathy, or persisting myocardial sinusoids. The etiology of NCCM is largely considered to be genetic—regarded as an autosomal dominant inherited disorder—resulting in disruption of compaction of loose myocardial meshwork during fetal development.

Structurally, NCCM has been identified as "including a 2-layered ventricular wall, comprising a thinner compact epicardial layer and an inner non-compacted layer, with prominent trabeculations associated with deep, intertrabecular recesses that communicate with the ventricular cavity but not with the coronary circulation."

Epidemiology

NCCM is considered rare, and the prevalence is still uncertain. It has been reported that about 3% to 4% of patients with heart failure have NCCM. Other sources report that NCCM is the third most common type of diagnosed cardiomyopathy. However, there is a wide variation in prevalence statistics due to challenges in recognition of this type of cardiomyopathy. In recent years, there has been an increase in the diagnosis of NCCM—likely due to increased awareness, improved imaging technology, and recommendations for screening in families with NCCM history.

Clinical Manifestations and Diagnosis

The clinical presentation of NCCM is variable. Clinical manifestations range from asymptomatic (diagnosed only through screenings) to progressive cardiac function decline and complications such as heart failure, arrhythmias, thromboembolic events, or sudden cardiac death. These complications—heart failure, arrhythmias (including sudden cardiac death), and thromboembolic events—make up the NCCM complication triad and are associated with unfavorable prognosis.

Echocardiogram is the first-line diagnostic modality for NCCM. It allows visualization and measurement of the degree of myocardial trabeculations. Cardiac MRI is another diagnostic method. It can help confirm the presence of anatomic features of NCCM and elicit accurate measurement of the compacted and non-compacted layers. The electrocardiographic findings can be nonspecific, but patients with NCCM may have evidence of left ventricular hypertrophy and repolarization abnormalities. It is important to note that the ECG can be normal, especially in asymptomatic patients. Genetic testing is done to determine the specific NCCM phenotypes and for family screenings.

Management

The main objectives of management are prevention and control of the triad of NCCM complications: Guideline-directed management and prevention of heart failure, arrhythmias, and thromboembolic events should be instituted in patients with NCCM. For advanced symptomatic NCCM with features of advanced heart failure, advanced therapies such as heart transplant should be a part of the therapeutic options and considerations.

References
  • Almeida AG, Pinto FJ. Non-compaction cardiomyopathy. Heart. 2013;99:1535.
  • Hänselmann A, et al. Dilated cardiomyopathies and non-compaction cardiomyopathy. Herz. 2020;45:212.
  • Towbin JA, et al. Left ventricular non-compaction cardiomyopathy. Lancet. 2015;22:813.

Filed under: Cardiometabolic

Development Widget