Sex differences in patients with and without high-risk factors associated with aneurysmal subarachnoid hemorrhage

Background Controversy remains regarding the appropriate screening for intracranial aneurysms or for the treatment of aneurysmal subarachnoid hemorrhage (aSAH) for patients without known high-risk factors for rupture. This study aimed to assess how sex affects both aSAH presentation and outcomes for aSAH treatment. Method A retrospective cohort study was conducted of all patients treated at a single institution for an aSAH during a 12-year period (August 1, 2007-July 31, 2019). An analysis of women with and without high-risk factors was performed, including a propensity adjustment for a poor neurologic outcome (modified Rankin Scale [mRS] score > 2) at follow-up. Results Data from 1014 patients were analyzed (69% [n = 703] women). Women were significantly older than men (mean +/- SD, 56.6 +/- 14.1 years vs 53.4 +/- 14.2 years, p < 0.001). A significantly lower percentage of women than men had a history of tobacco use (36.6% [n = 257] vs 46% [n = 143], p = 0.005). A significantly higher percentage of women than men had no high-risk factors for aSAH (10% [n = 70] vs 5% [n = 16], p = 0.01). The percentage of women with an mRS score > 2 at the last follow-up was significantly lower among those without high-risk factors (34%, 24/70) versus those with high-risk factors (53%, 334/633) (p = 0.004). Subsequent propensity-adjusted analysis (adjusted for age, Hunt and Hess grade, and Fisher grade) found no statistically significant difference in the odds of a poor outcome for women with or without high-risk factors for aSAH (OR = 0.7, 95% CI = 0.4-1.2, p = 0.18). Conclusions A higher percentage of women versus men with aSAH had no known high-risk factors for rupture, supporting more aggressive screening and management of women with unruptured aneurysms.