Abstract A044: Primary Prevention of Ischemic Stroke with Aspirin or Statins for Patients with Fibromuscular Dysplasia: A Retrospective Case-Control Study

Introduction: Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory vasculopathy predominantly affecting medium-sized, muscular arteries (e.g., carotid and renal). FMD is associated with cerebrovascular complications, including cervical artery dissection and intracranial aneurysms, but primary prevention of stroke in patients with FMD remains controversial despite consensus guidelines recommending daily aspirin use. This study aims to assess the efficacy of aspirin and statin use in the primary prevention of stroke for patients with FMD. Hypothesis: Adults with FMD taking aspirin or statins have lower odds of ischemic stroke compared to those not on aspirin or statins. Methods: This study identified adults with FMD using Epic SlicerDicer (a de-identified, aggregate medical record database) at a single academic medical center participating in the North American Registry for FMD. Exclusions included diagnosis of malignancy, thrombophilia, connective tissue disease, prior myocardial infarction, or stroke before FMD diagnosis. The outcome of interest was ischemic stroke, while the variables of interest were antecedent aspirin or statin use. Statistical analysis was conducted via multivariable logistic regression, stratifying by age and sex, to determine odds and associated 95% confidence intervals. Results: A total of 1438 patients with FMD were identified, with 385 excluded, leaving 1053 patients eligible. Of these, 806 (76.5%) were on aspirin, and 593 (56.3%) were on statins. Ischemic stroke followed FMD diagnosis in 30 (2.8%) patients. Aspirin use was associated with significantly decreased odds of ischemic stroke compared to those not on aspirin (OR: 0.33 [0.17-0.70], p-value: 0.004). Patients aged 60-69 years had the lowest odds (OR: 0.095 [0.02-0.55], p-value: 0.009). Women (OR: 0.40 [0.02-0.87], p-value: 0.021) had a higher risk of ischemic stroke than men (0.061 [0.005-0.825], p-value: 0.035). Statin use was not associated with any statistically significant change in odds (OR: 0.55 [0.28-1.17], p-value: 0.118). Conclusions: Aspirin use was associated with a statistically significant reduction in the odds of ischemic stroke in patients with a diagnosis of FMD. Statins were not associated with a change in odds of ischemic stroke. Further investigation is underway, including adjudication and subtyping of stroke outcomes and validation within the North American Registry for FMD.