Sex differences in aneurysmal subarachnoid haemorrhage (aSAH): aneurysm characteristics, neurological complications, and outcome

Background: Women are over-represented in aSAH cohorts, but whether their outcomes differ to men remains unclear. We examined if sex differences in neurological complications and aneurysm characteristics contributed to aSAH outcomes.

Methods: In a retrospective cohort (2010-2016) of all aSAH cases across two hospital networks in Australia, information on severity, aneurysm characteristics and neurological complications (rebleed before/after treatment, postoperative stroke < 48 h, neurological infections, hydrocephalus, seizures, delayed cerebral ischemia [DCI], cerebral infarction) were extracted. We estimated sex differences in (1) complications and aneurysm characteristics using chi square/t-tests and (2) outcome at discharge (home, rehabilitation or death) using multinomial regression with and without propensity score matching on prestroke confounders.

Results: Among 577 cases (69% women, 84% treated) aneurysm size was greater in men than women and DCI more common in women than men. In unadjusted log multinomial regression, women had marginally greater discharge to rehabilitation (RRR 1.15 95% CI 0.90-1.48) and similar likelihood of in-hospital death (RRR 1.02 95% CI 0.76-1.36) versus discharge home. Prestroke confounders (age, hypertension, smoking status) explained greater risk of death in women (rehabilitation RRR 1.13 95% CI 0.87-1.48; death RRR 0.75 95% CI 0.51-1.10). Neurological complications (DCI and hydrocephalus) were covariates explaining some of the greater risk for poor outcomes in women (rehabilitation RRR 0.87 95% CI 0.69-1.11; death RRR 0.80 95% CI 0.52-1.23). Results were consistent in propensity score matched models.

Conclusion: The marginally poorer outcome in women at discharge was partially attributable to prestroke confounders and complications. Improvements in managing complications could improve outcomes.