A Closer Look at Potential Underlying Factors Related to Possible Disparity Between Sexes in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

<b>Background</b>: Aneurysmal subarachnoid hemorrhage (SAH) is over twice as common in females compared to males, who may also experience more severe hemorrhages and worse outcomes. Differences in SAH severity, susceptibility to delayed cerebral ischemia (DCI), and treatment responsiveness may underlie this disparity. This study evaluated sex-based differences in DCI timing, severity, treatment responsiveness, and outcomes after SAH. <b>Methods</b>: We analyzed 650 consecutive SAH patients admitted to RWTH Aachen University Hospital (2006-2021). SAH severity was assessed via the (World Federation of Neurological Surgeons) WFNS and modified Fisher scales. DCI-related infarction was defined as new infarcts on CT not present initially or within 48 h post-aneurysm occlusion. Endovascular rescue therapy (ERT) was used for treatment-resistant DCI. Outcomes were assessed at discharge and 12 months using the modified Rankin Scale (mRS). Generalized linear mixed-effects models adjusted for confounders. <b>Results</b>: Of 650 patients, 455 (70%) were female. DCI rates did not differ significantly between sexes (41.5% female vs. 36.4% male; <i>p</i> = 0.361). DCI-related infarction occurred in 19.4% of patients, with no sex-based differences in infarct volume (median 115 mL; <i>p</i> = 0.670) or location. ERT use was similar in females (22.4%) and males (23.9%; <i>p</i> = 0.825). Lower age, poor-grade SAH, and higher mFisher scores were associated with DCI and poor outcomes, but sex was not an independent predictor. <b>Conclusions</b>: Female sex was not associated with more severe SAH, a higher incidence of DCI, or more severe DCI manifestations. Although small effect sizes may become statistically significant in larger cohorts, our findings indicate that such effects are unlikely to be driven by differences in DCI timing, infarct size, or treatment responsiveness.