Sex-based differences in inflammatory predictors of outcomes in patients undergoing mechanical thrombectomy: an inverse probability weighting analysis

Background: Inflammatory biomarkers, key predictors of ischemic stroke prognosis, may exhibit sex-specific predictive patterns. Objectives: This study investigates sex-based differences in inflammatory biomarkers as predictors of 90-day clinical outcomes in acute ischemic stroke patients undergoing mechanical thrombectomy (MT). Design: Multicenter retrospective study. Methods: This study included 970 patients consecutively treated with MT for anterior circulation large vessel occlusion between 2016 and 2023. Inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio (MLR), C-reactive protein (CRP), systemic inflammation response index, and systemic immune-inflammation index, were measured on admission and 24-h post-MT. Inverse probability weighting was used to balance baseline characteristics between male and female patients. Least absolute shrinkage and selection operator regression and logistic regression were used to identify independent predictors of 90-day good functional outcomes (modified Rankin scale (mRS) score 0–2) and death, stratified by sex and age groups (<55 and ⩾55 years). Results: In the male weighted population (516 patients), multivariable analysis showed that MLR (odds ratio (OR): 0.37, 95% confidence interval (CI): 0.13–0.95, p = 0.041), 24-h NLR (OR: 0.88, 95% CI: 0.83–0.94, p < 0.001), and 24-h MLR (OR: 0.33, 95% CI: 0.12–0.94, p < 0.001) were independent predictors of 90-day good functional outcome with age-specific differences noted. Twenty-four-hour MLR (OR: 5.05, 95% CI: 1.36–4.28, p = 0.047) and erythrocyte sedimentation rate (OR: 1.02, 95% CI: 1.01–1.04, p = 0.025) were independent predictors of death, respectively, for men <55 and men ⩾55 years. In the weighted female population (454 patients), 24-h NLR (OR: 0.89, 95% CI: 0.81–0.96, p = 0.007) and 24-h CRP (OR: 0.98, 95% CI: 0.97–0.99, p = 0.029) were independent predictors of good functional outcomes. Twenty-four-hour CRP was also an independent predictor of 90-day death (OR: 1.01, 95% CI: 1.00–1.02, p = 0.017) in women with no age-specific differences noted. Interaction analysis revealed significant sex-specific relationships for MLR and CRP but not for NLR. Conclusion: This study highlights sex-based differences in the predictive value of widely available inflammatory biomarkers for stroke outcomes. MLR was a distinct predictor in men, while CRP was uniquely associated with outcomes in women. These findings underscore the need for sex-stratified approaches in stroke management and research.