The likelihood of rupture of unruptured intracranial aneurysms that were less than 10 mm in diameter was exceedingly low among patients in group 1 and was substantially higher among those in group 2. The risk of morbidity and mortality related to surgery greatly exceeded the 7.5-year risk of rupture among patients in group 1 with unruptured intracranial aneurysms smaller than 10 mm in diameter.

No abstract

The prevalence of ASA based on this population-based study is 2.2%. The frequency of ASA is relatively higher in patients evaluated with transesophageal echocardiography after a cerebral ischemic event. ASA is frequently associated with PFO, suggesting paradoxical embolism as a mechanism of cardioembolism. In patients with cerebral ischemia and ASA, ASA (with or without PFO) commonly is the only potential cardioembolic source detected with transesophageal echocardiography.

Background and Purpose Chronic inflammation is postulated as an important phenomenon in intracranial aneurysm (IA) wall pathophysiology. This study was conducted to determine if aspirin use impacts the occurrence of IA rupture. Methods Subjects enrolled in the International Study of Unruptured Intracranial Aneurysms (ISUIA) were selected from the prospective untreated cohort (n=1691) in a nested case-control study. Cases were subjects who subsequently suffered a proven aneurysmal SAH during a 5-year follow-up period. Four controls were matched to each case by site and size of aneurysm (58 cases, 213 controls). Frequency of aspirin use was determined at baseline interview. Aspirin frequency groups were analyzed for risk of aneurysmal hemorrhage. Bivariable and multivariable analyses were performed using conditional logistic regression. Results A trend of a protective effect for risk of UIA rupture was observed. Patients who used aspirin 3x weekly - daily had an odds ratio (OR) for hemorrhage of 0.40 [95% CI=0.18-0.87, reference group = no use of aspirin], patients in the “< once a month” group had an OR of 0.80 (95% CI=0.31-2.05) and patients in the “> once a month – 2x/week” group had an OR of 0.87 (95% CI=0.27-2.81) (p= 0.025). In multivariable risk factor analyses, patients who used aspirin three times weekly to daily had a significantly lower odds of hemorrhage (Adjusted OR=0.27, 95% CI 0.11-0.67, p=0.03) compared to those who never take aspirin. Conclusions Frequent aspirin use may confer a protective effect for risk of IA rupture. Future investigation in animal models and clinical studies is needed.