Cardiomyopathy genetic testing: insights into demographics, counseling, and cascade screening.

Background: Genetic testing (GT) is clinically indicated for patients with suspected inherited cardiomyopathy (CM) but is underutilized.

Methods: This single-center study included patients with CM who underwent outpatient GT from 2018 to 2023. Data were collected from the medical record.

Results: A total of 306 patients were included, with a mean age of 62 years and were predominantly male (63%) and White (59%). Heart failure (92%) cardiologists were most likely to order testing, followed by general cardiology (5%) providers at tertiary hospital clinics (89%). The most common phenotypes were hypertrophic (30%), amyloid (29%) and dilated (21%). There were 17% of patients who had a positive test and 53% of patients who had a variant of uncertain significance. Patients with a positive family history had a significantly higher positive yield compared to those without (p < 0.01). Genetic counselors were underutilized (17%). For patients who had a positive test result, only 40% had cascade screening.

Conclusions: Outpatient GT for CM was primarily ordered by heart failure cardiologists in tertiary hospital clinics. Cascade screening was low, which may reflect the limited use of genetic counselors. Further research is needed to understand implementation barriers to GT.