Idiopathic dilated cardiomyopathy (DCM), the most common type of heart failure in the United States, was found to have a familial etiology in 30 percent of individuals diagnosed with DCM, and the overall risk for a family member of developing DCM was nearly 20 percent by the age of 80, according to a family-based, cross-sectional study published in JAMA.
"This study is incredibly important because our goal at the outset was to create a large, diverse cohort of patients with DCM and their families to understand the risk of developing heart failure simply by being related to someone who has DCM," said Jane Wilcox, MD, '15 MSc, '10, '11 GME, associate professor of Medicine in the Division of Cardiology and a co-author of the study.
Dilated cardiomyopathy, one of the leading causes of heart failure in the U.S., is when one or both of the heart's ventricles stretches, or "dilates," and becomes weaker, and many patients will ultimately require a heart transplant. In the case of DCM, the cause of the heart muscle's dysfunction is often unknown, though recently investigators have learned that many cases are common in families, suggesting a genetic cause.
Furthermore, Black patients, who have a higher risk of heart failure hospitalization and death, have historically been underrepresented in clinical trials exploring heart failure, underscoring the importance of including more diverse patient cohorts in studies, according to Wilcox.
In the current study, 1,220 patients with DCM and their 1,693 first-degree relatives were recruited from 25 heart failure programs across the U.S. Participants with DCM demonstrated left ventricular systolic dysfunction and enlargement of the heart's left ventricle. The initial DCM patients were an average age of 53 years, 44 percent female, and 43 percent were Black, while 8 percent were Hispanic.
Through heart failure screenings, the investigators discovered that familial DCM was prevalent in 30 percent of patients with DCM and the risk of developing DCM by age 80 years in their family members was 19 percent. Notably, DCM risk was also higher for Black individuals compared to white individuals.
These findings emphasize that heart failure screening should be of the same rigor and consistency as is screening for other genetic illnesses, especially among Black individuals, Wilcox said.
Just like women should get a mammogram earlier if they have a family history of breast cancer, family members at risk for DCM should talk with their doctors about getting screened with an echocardiogram and talk with a cardiologist about their risk for heart failure."
Jane Wilcox, MD, Study's Co-Author
This study was supported by National Heart, Lung, and Blood Institute R01HL128857 and a supplement from the National Human Genome Research Institute.
Huggins, G.S., et al. (2022) Prevalence and Cumulative Risk of Familial Idiopathic Dilated Cardiomyopathy. JAMA. doi.org/10.1001/jama.2021.24674.