Abstract 4364899: Trends and Disparities in Genetic Testing Among Patients at Risk for Heritable Thoracic Aortic Disease: A Multicenter Cohort Study

Introduction: Heritable thoracic aortic disease (HTAD) encompasses a spectrum of genetic syndromes and mutations that increase the risk of aortic aneurysm, dissection, and rupture. International guidelines recommend genetic evaluation in patients with thoracic aortic disease diagnosed before age 60, those with a family history of thoracic aortic dissection, and individuals with aneurysms in other vascular beds. Despite recommendations, real-world uptake of genetic testing remains unclear. Research Question: This study examined national trends in genetic testing among patients at elevated risk for HTAD using a large multicenter health network, evaluating adherence to testing recommendations and disparities across demographic subgroups. Methods: A retrospective cohort study was conducted using TriNetX, a federated database of de-identified EHRs from academic and community health systems across the U.S. Three guideline-based risk cohorts were identified using ICD-10 codes: thoracic aortic aneurysm or dissection diagnosed before age 60, family history of TAD, and non-thoracic arterial aneurysms. Genetic testing was defined using codes for screening or confirmed genetic diagnoses. Demographic variables included age, sex, race, and ethnicity. Results: Among 57,935 patients diagnosed with thoracic aortic disease before age 60, genetic testing prevalence was 2.09%, higher in females (3.56%) than males (1.50%), and most common in children aged 0–9 (4.6%). By race/ethnicity, testing was highest in American Indian/Alaska Native (4.98%). In 2,811,862 patients with a family history of TAD, testing prevalence was 2.38%, higher in females (3.12%) than males (1.37%) and most common in those aged 10–19 (~4.6%). Among 347,000 patients with non-thoracic aneurysms, testing prevalence was 1.42%, higher in females (1.80%) than males (1.08%), and most frequent in ages 10–19 (~2.8%). By race, rates were highest in White patients (1.60%), followed by Black or African American (1.23%) patients. Conclusion: Genetic testing for heritable aortic disease is markedly underutilized, with fewer than 2.5% of at-risk patients screened, even when clinically indicated. Testing rates were consistently low across age, sex, and racial/ethnic groups, though modestly higher in younger patients and females. The higher testing rate in women may reflect data that shows a more severe disease progression in women, despite higher overall prevalence in men. These findings reveal a gap between guidelines and practice.