Recent advances in biotechnology provide an opportunity to interrogate the human genome in a highly efficient, rapid and cost-effective manner, augmenting our understanding of the genetic underpinnings of many diseases, including cardiomyopathy. The genetic basis of hypertrophic cardiomyopathy has been recognized for some time, but it was not known until recently that at least one-third of so-called idiopathic dilated cardiomyopathy (IDCM) cases have a genetic (familial) basis. Familial dilated cardiomyopathy (DCM) is usually inherited in an autosomal dominant mode, so a three-generation detailed family history is recommended when a patient presents with DCM. However, the family history has low negative predictive value for a variety of reasons, including inaccurate classification or incomplete knowledge of family deaths and the genetic phenomena of incomplete penetrance and variable expressivity. The Temple Inherited Cardiomyopathy Program (TICP) directed by Daniel L. Dries, MD, combines family history and targeted genetic screening to better identify, counsel and treat patients with familial DCM or its genetic risk factors.
The most recent HRS/EHRA Expert Consensus Statement on the State of Genetic Testing for the Channelopathies and Cardiomyopathies1 recommends that genetic testing be conducted in all cases of DCM, and that all of a patient’s first-degree relatives be screened. This is especially recommended in cases of idiopathic dilated cardiomyopathy with associated cardiac conduction disease or family history of sudden cardiac death. Current technologies allow the identification of the disease-causing variant in approximately 40 to 50 percent of hypertrophic cardiomyopathy cases. Family screening can then be facilitated by testing at-risk first-degree relatives for this specific mutation.
The TICP provides comprehensive diagnostic and management assistance for the full spectrum of inherited cardiomyopathies. The initial evaluation includes extending the pedigree, genetic counseling and targeted genetic testing, and the Program’s trained staff makes recommendations for screening potentially at-risk, asymptomatic family members.
The Temple Inherited Cardiomyopathy Program helps diagnose and manage all inherited myopathies, including:
- Familial dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Arrhythmogenic cardiomyopathy (formerly called arrhythmogenic right ventricular dysplasia)
- Left-ventricular non-compaction
- Restrictive cardiomyopathy
- Cardiac amyloid disease
The Temple Hypertrophic Cardiomyopathy (HCM) Program consists of a multidisciplinary care team that provides services spanning the full spectrum of HCM care—including evaluation, genetic testing and family screening, genetic counseling, assessment of risk for sudden cardiac death and need for implantable cardiac defibrillator, and counseling for activity restrictions if any. The HCM Program also offers state-of-the-art cardiac imaging, including quantification of cardiac fibrosis (a newly recognized independent criterion in HCM patients for placement of a cardiac defibrillator for primary prevention of sudden cardiac death) and identification of patients who may benefit from surgical septal myectomy or alcohol septal ablation, both procedures that are available at Temple.