Multi-Center Study Finds Routine Genetic Testing Could Benefit Patients with Advanced Inherited Heart Muscle Disease

WASHINGTON – Genetic testing is an essential tool to look for gene mutations known to cause various inherited heart conditions, including cardiomyopathy, a condition that affects the heart muscle and makes it harder for the heart to pump blood to the rest of the body. Now, a multi-site, five-year study led by a MedStar Heart & Vascular Institute cardiologist and fellow researchers from across the country have demonstrated the benefits of routine genetic testing for patients with advanced disease from dilated cardiomyopathy (DCM), a disease of the heart muscle and their at-risk family members.

The DCM Precision Medicine Study analyzed clinical and genetic sequence data from 1,265 patients at 25 leading academic U.S. heart failure and heart transplant programs that are part of the Dilated Cardiomyopathy Consortium. It found DCM patients with advanced heart disease, defined as having a heart transplant or a mechanical heart pump called left ventricular assist device, or LVAD, were more than twice as likely to carry a disease-causing mutation in a relevant DCM gene than those without advanced heart disease.

“For years, we have known that dilated cardiomyopathy runs in families, but genetic testing is rarely performed on patients who had received heart transplants or LVADs,” said Mark Hofmeyer, MD, medical director of the Advanced Heart Failure Intermediate Care Unit at MedStar Heart & Vascular institute at MedStar Washington Hospital Center and the first author of the DCM Precision Medicine study. “These study results validate the concept that routine genetic testing performed on these patients allows us to identify their family members who may be at risk of developing DCM and when early signs of disease do appear, we can begin earlier treatment in those family members, perhaps ultimately avoiding the need for either heart transplantation or mechanical circulatory support.”

Dilated cardiomyopathy occurs when the heart muscle becomes weakened and the heart becomes enlarged, reducing its ability to pump blood throughout the body. It can occur at any age, although the typical onset is in the mid-40s. Symptoms may include shortness of breath, fatigue, swelling of the legs and feet, and irregular heartbeat. In severe cases, it can lead to heart failure or sudden cardiac death caused by abnormal heart rhythms.

“This is the first time that the association of rare variant genetics with advanced DCM has been systematically studied. Our study results provide additional insight for providers to help DCM patients manage their disease and improve their outcome,” added Dr. Hofmeyer.

Results of the study were published online this week, ahead of print publication, in the American Heart Association’s journal Circulation.

The DCM Consortium was funded by a $12.4 million grant from the National Heart, Lung, and Blood Institute of the National Institutes of Health and a supplemental grant from the National Human Genome Research Institute.