Aneurysm Wall Enhancement in Patients With Unruptured Intracranial Aneurysm Using Aspirin or Statins: A Cross-Sectional Analysis of Three Prospective Cohorts

OBJECTIVE: To investigate the association between use of aspirin or statins and aneurysm wall enhancement (AWE) on 3T magnetic resonance vessel wall imaging (MR-VWI) in patients with unruptured intracranial aneurysms (UIAs). METHODS: For this cross-sectional study, we obtained individual patient data from three prospective UIA follow-up registries in which patients underwent 3.0T MR-VWI. Regular medication use was defined as aspirin ≥100 mg at least three times per week for ≥6 months, and statins at ≥20 mg daily for ≥6 months. AWE was classified as no AWE (no visible enhancement), focal AWE (enhancement limited to part of the aneurysm wall), or circumferential AWE (enhancement involving the entire wall). Multivariable ordinal logistic regression was used to assess the association between medication use and AWE in the full cohort. To isolate the effect of each drug, we conducted two separate propensity score matching analyses (PSM): statin users were excluded from the aspirin analysis, and aspirin users from the statin analysis. Logistic regression analyses were repeated within each matched group. RESULTS: We included 1351 patients with 1416 UIAs, of whom 141 (10.4%) used aspirin and 145 (10.7%) used statin. In the full cohort, multivariable ordinal logistic regression showed that aspirin use was associated with a lower likelihood of AWE (OR=0.51; 95%CI, 0.35-0.74), whereas statin use was not significantly associated with AWE (OR=1.44; 95% CI, 0.98-2.12). PSM based on age, sex, hypertension, diabetes, dyslipidemia, and aneurysm size yielded 83 matched pairs in the aspirin cohort and 97 in the statin cohort. In the matched cohorts, aspirin use remained inversely associated with AWE (OR=0.47; 95% CI, 0.26-0.85), while statin use remained unassociated (OR=1.49; 95% CI, 0.88-2.50). CONCLUSION: In this cross-sectional analysis, aspirin use was independently associated with reduced AWE in patients with UIAs, while statin use was not. However, the cross-sectional design precludes causal inference regarding a direct anti-inflammatory effect on the aneurysm wall.