Impact of Demographic Factors on Aneurysm Risk in Brain Arteriovenous Malformations

Background Brain arteriovenous malformations (bAVMs) are a significant cause of intracranial hemorrhages but can also present with seizures, headaches, and focal neurologic deficits. bAVM‐associated aneurysms have been hypothesized to increase hemorrhage risk and are often categorized as flow‐related and peri‐/intra‐nidal. Best management of these aneurysms is controversial because high‐quality data is sparse. This study aims to characterize bAVM‐associated aneurysms, assess their relationship to rupture risk, and evaluate demographic and clinical risk factors for aneurysm presence. Methods A retrospective review of patients presenting at a tertiary care academic medical center from 2010 to 2023 identified 214 patients with an AVM of the cerebrovascular system. Baseline clinical and demographic data was collected, and relevant imaging (CT, CTA, cerebral angiogram) were reviewed. All bAVM patients, whether ruptured or unruptured, were included in the statistical analysis. Logistic regression analysis and Cox proportional hazards models were conducted to assess the associations between aneurysm presence and type, patient demographics, and rupture risks. Results bAVM‐associated aneurysms were found in 29.4% of patients, with intra‐/peri‐nidal being the most common subtype (n=41), followed by flow‐related (n=22). While aneurysm presence was not found to be statistically significantly associated with rupture status (p=0.417), older age (HR=1.045; p=0.032) and male sex (HR=12.07; p=0.025) were associated with increased rupture risk. Caucasian race, on the other hand, was found to have a protective effect against AVM rupture (HR=0.075; p=0.032). Aneurysms were most frequently observed in Caucasian patients (44.4%), followed by Hispanic (20.6%), Other (14.3%), and Asian patients (7.9%), with race showing a borderline association with aneurysm presence (p=0.072). When stratifying by rupture status, 50.5% experienced at least 1 rupture during their clinical course, while 49.5% did not. Aneurysms were present in 32.4% of ruptured patients of ruptured patients and 26.4% of unruptured patients (p=0.417). These findings suggest that aneurysm presence alone does not significantly account for rupture risk in this cohort; rather, demographic factors appear to provide better prognostication for clinical outcomes. Conclusions Aneurysm presence and subtype were not found to predict ruptures in bAVM patients. Age, sex, and race were found to be more robust predictors of clinical course and outcome in patients with AVMs.