Rosenbaum, Blake L.

Background: The risk for intracranial (IA) and abdominal aortic aneurysms (AAA) is partially heritable, with evidence mounting in favor of shared genetic risk for both. Methods: The Brain and Aortic Aneurysm Study (BAAS, NCT#17341) at University of Virginia seeks to determine the coprevalence of IA and AAA recruiting patients presenting with an aneurysm at one site and screening for aneurysm at the other. Participants undergo genetic screening and an interview where clinical, demographic, and radiographic data are collected. Recruitment and screening are ongoing, so preliminary demographic data regarding between group differences (IA vs. AAA) are presented. All clinical and demographic data were collected and recorded in REDCap and exported to Excel. We compared a total of 256 participants (IA=164, AAA=92) for demographic factors: age, sex, smoking and past medical history. Results: The AAA cohort was older (70.98 vs. 58.51, p<.001) and more male (79.34% vs. 23.78% p<.001). The AAA cohort had a higher proportion with diabetes mellitus (28.26% vs. 15.24%, p=.012), with hyperlipidemia (67.39% vs. 44.51%, p<.001) and higher smoking pack years (44.07 vs. 17.85, p<.001). The two groups did not differ in proportion with hypertension, coronary artery disease, or peripheral vascular disease (all p>.05). Conclusions: These data suggest that there may be subtle differences in the clinical profile of patients presenting with IA and AAA, especially when considering known aneurysmal risk factors like hypertension, diabetes, and smoking history. Further analyses will consider whether these factors modulate the coprevalence of the two types of aneurysms.

Introduction: Aneurysm rupture is associated with high mortality and morbidity, including both intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA). Despite potential preemptive treatment in those identified prior to IA or AAA rupture, the evidence for whom to screen remains limited. IA and AAA share both environmental and genetic risk, and prior cost-effectiveness models suggest the potential efficacy of screening in these high-risk individuals. We hypothesized that reciprocal screening in those presenting with IA for AAA would yield positive results. Methods: The BAAS study sought to establish the co-prevalence of IA and AAA. In this arm of BAAS, we recruited patients presenting with IA and screened them for AAA using abdominal ultrasound (aU/S) at two sites: Mayo Clinic and the University of Virginia (UVA). All participants underwent a detailed interview to collect demographic, radiographic, and clinical data. At UVA, participants also received genetic counseling. Results: At Mayo Clinic, we enrolled and screened 81 consecutive patients with aSAH (3 patients with known AAA were excluded) with 3 (3.7%) positive aU/S for AAA. At UVA, we recruited 195 consecutive patients presenting with ruptured or unruptured IA and completed screening aU/S in 178 (93%). Only one (0.6%) had an AAA. Conclusion: The lower positive screening at UVA (0.6%) which enrolled both ruptured and unruptured IA compared to the 3.7% positive results at Mayo suggests that future efforts to identify who with IA might benefit from AAA screening should focus on those with aneurysmal subarachnoid hemorrhage (aSAH).

Introduction: Abdominal aortic aneurysm (AAA) rupture has a mortality rate of 64% and intracranial aneurysm (IA) rupture has a mortality rate of 50%. Despite the high mortality rates, early detection and treatment of these vascular lesions prior to rupture can prevent devastating clinical outcomes, underscoring the need to identify high-risk populations for screening. Current evidence demonstrates shared genetic and environmental risk factors for both AAA and IA. Methods: The BAAS study sought to establish the co-prevalence of AAA and IA. In one arm of BAAS, we recruited patients presenting with AAA and screened them for IA. All participants underwent a detailed interview to collect demographic, radiographic, and clinical data and also had genetic counseling. Results: Of the 126 individuals with an AAA enrolled, 65% (82/126) completed the MRA. Difficulty with logistics of obtaining the research MRA with long distance travel to clinic was the principal reason for failure to obtain MRA. We identified 20.7% (17/82) with one or more IA, including 21 aneurysms found during systematic screening. IA ranged in size from 1.5-14 mm (height) x 1.4-7 mm (width) and varied in location. 9.5% (2/21) had a maximum diameter of 7 mm or more. One participant with a positive MRA underwent early coil embolization with the remainder undergoing continued clinical surveillance. Of the 15 individuals completing the genetic counseling screening, two underwent recommended clinical genetic testing, revealing one negative screen and one variant of unknown significance in the MYH11 gene. Conclusion: Consistent with our prior cost effectiveness models, these prospective data support the clinical utility of routine screening for IA in patients presenting with AAA.