Family members of patients with idiopathic dilated cardiomyopathy have a “substantial” one-in-five risk of developing the condition, supporting a role for wider screening, researchers say.

Early identification in at-risk family members could provide the opportunity to initiate treatment early but accurate recent estimates of the prevalence of familial dilated cardiomyopathy (DCM) have been lacking, the US team says.

They conducted a cross-sectional study of 1220 patients with DCM, defined as left ventricular systolic dysfunction and left ventricular enlargement after excluding usual clinical causes, and 1693 of their first-degree relatives.

The prevalence of familial DCM was estimated at 29.7% in first-degree relatives and the estimated cumulative risk of DCM by age 80 years in family members was 19%, they reported in JAMA.