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 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 interquartile range: 7 mL 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 from sex-specific interpretation of early infarct volume in clinical practice.