Supplementary Material for: Sex alters the effect of perfusion deficits on functional outcome in patients with acute ischemic stroke undergoing mechanical thrombectomy

Introduction: The discourse surrounding differences in cerebral hemodynamics and clinical outcomes among male and female patients treated with mechanical thrombectomy (MT) for acute ischemic stroke (AIS) remains unresolved. We aimed to elucidate these differences by employing computed tomography perfusion (CTP) imaging before MT and examining the influence of perfusion deficits on the 90-day functional outcome. Methods: This single-center retrospective analysis involved patients with anterior circulation AIS treated with MT at the Comprehensive Stroke Center, University Hospital, Krakow from January 2019 to July 2023. We compared male and female patients in terms of baseline characteristics, CTP deficits, hypoperfusion intensity ratio (HIR, defined as T10max/T6max) and complications. The endpoints included the 90-day excellent functional outcome, defined as modified Rankin Score (mRS)<2, and the 90-day mortality rate. Results: We included 794 patients, of whom 408 were female (51.4%). Female patients had a smaller early infarct volume (median: 7 mL; IQR: [0-24.8] vs 10 mL [0-33], p=0.004), smaller penumbra volume (77.5 mL [46-117] vs 99.5 mL [59.8-140], p<0.001), lower HIR (0.34 [0.16-0.5] vs 0.37 [0.2-9.53], p=0.043) and were less likely to achieve an excellent functional outcome (55.6% vs 66.1%, p=0.003). For every 10 mL increase in early infarct volume, the odds for achieving an excellent outcome were lower in females (odds ratio (OR): 0.82 [95% confidence interval: 0.73-0.92]) compared to males (OR: 0.96 [0.88-1.04]), whereas the risk of death was higher for females (OR: 1.25 [1.13-1.39] than for males (OR: 1.05 [0.98-1.14]). Discussion: Despite more favorable cerebral hemodynamic profile, female AIS patients have worse outcomes than their male counterparts. This effect seems to be independently mediated by the more pronounced impact of early infarct volume on the prognosis in female patients. These findings underscore the possible explanatory power arising for from sex-specific interpretation of early infarct volume in clinical practice.

引言：目前关于接受机械取栓术（mechanical thrombectomy, MT）治疗的急性缺血性脑卒中（acute ischemic stroke, AIS）患者中，男性与女性的脑血流动力学差异及临床结局的相关讨论仍未达成共识。本研究旨在通过机械取栓术前的计算机断层扫描灌注（computed tomography perfusion, CTP）成像，明确上述差异，并探究灌注缺损对患者90天功能预后的影响。

方法：本研究为单中心回顾性分析，纳入2019年1月至2023年7月期间，克拉科夫大学医院综合卒中中心接受机械取栓术治疗的前循环急性缺血性脑卒中患者。我们对比了男性与女性患者的基线特征、CTP灌注缺损情况、低灌注强度比（hypoperfusion intensity ratio, HIR，定义为T10max/T6max）及并发症情况。本研究的终点事件包括90天优良功能预后（定义为改良Rankin量表（modified Rankin Score, mRS）评分<2分）及90天死亡率。

结果：本研究共纳入794例患者，其中女性408例（占比51.4%）。与男性患者相比，女性患者的早期梗死体积更小（中位数：7 mL；四分位距[IQR]：0~24.8 mL vs 10 mL [0~33 mL]，p=0.004），半暗带体积更小（77.5 mL [46~117 mL] vs 99.5 mL [59.8~140 mL]，p<0.001），低灌注强度比更低（0.34 [0.16~0.5] vs 0.37 [0.2~9.53]，p=0.043），且达到优良功能预后的比例更低（55.6% vs 66.1%，p=0.003）。当早期梗死体积每增加10 mL时，女性患者达到优良功能预后的比值比（odds ratio, OR）为0.82 [95%置信区间（confidence interval, CI）：0.73~0.92]，低于男性患者的0.96 [0.88~1.04]；而女性患者的死亡风险更高（OR=1.25 [1.13~1.39]），高于男性患者的1.05 [0.98~1.14]。

讨论：尽管女性急性缺血性脑卒中患者的脑血流动力学特征更具优势，但其临床结局却劣于男性患者。这一差异似乎可通过早期梗死体积对女性患者预后的影响更为显著这一机制独立介导。本研究结果提示，在临床实践中针对早期梗死体积进行性别特异性解读，或可为解释上述性别差异提供理论依据。