Cardiomyopathy is a cardiovascular disease occurring in the heart muscles, which makes it harder for the heart to pump blood to the rest of the body. The prevalence of non-ischemic dilated cardiomyopathy (DCM) is higher in people of African ancestry, but whether this association is due to functional genetic variants is not clear. This study aims to investigate whether BAG3 genetic variants are associated with DCM outcomes.

This multicohort study included a total of 509 African American individuals with dilated cardiomyopathy. The information on the samples of DNA of the participants was acquired from three clinical studies: GRAHF, GRACE, and IMAC-2. The primary outcomes of the study were the prevalence of BAG3 mutations in African American individuals and event-free survival.

Of 509 African American participants, 4 BAG3 genetic variants were identified in 42 individuals (10.4%) with ischemic heart failure and 9 individuals with ischemic heart failure. Of 4 BAG3 variants, 2 were nonsynonymous single-nucleotide variants, 1 was three-nucleotide, in-frame insertion, and 2 were single-nucleotide variants. The findings also suggested that the presence of BAG3 variants was associated with a nearly 2-fold increase in cardiac events in carriers, as compared with non-carriers.

The research concluded that in DCM patients of African ancestry, BAG3 variants were not associated with the cause of the disease but were associated with negative outcomes.