Association between neutrophil-to-lymphocyte ratio and functional outcomes in patients with large vessel occlusion stroke treated with endovascular thrombectomy

Systemic inflammation plays a critical role in secondary brain injury following acute ischemic stroke. The neutrophil-to-lymphocyte ratio (NLR) has emerged as a readily accessible inflammatory biomarker; however, its prognostic value in large vessel occlusion (LVO) stroke patients undergoing endovascular thrombectomy (EVT) remains incompletely characterized. This study aimed to investigate the association between admission NLR and 90-day functional outcomes in LVO stroke patients treated with EVT. We conducted a retrospective cohort study of consecutive LVO stroke patients who underwent EVT at a comprehensive stroke center between January 2019 and December 2023. The primary outcome was poor functional outcome, defined as modified Rankin Scale (mRS) score of 3–6 at 90 days. Multivariable logistic regression, restricted cubic spline analysis, and subgroup analyses were performed to evaluate the association between NLR and outcomes. A total of 486 patients were included (mean age 66.75 ± 13.18 years; 50.82% female). The median NLR was 5.51 (interquartile range [IQR]: 3.98–8.26). Poor functional outcome occurred in 327 patients (67.28%). Patients with poor outcomes demonstrated significantly higher NLR compared to those with favorable outcomes (median 5.97 vs. 4.71; P < 0.001). After multivariable adjustment, each unit increase in NLR was independently associated with poor functional outcome (adjusted odds ratio [aOR]: 1.15; 95% confidence interval [CI]: 1.08–1.22; P < 0.001). Patients in the highest NLR tertile exhibited substantially elevated risk compared to the lowest tertile (aOR: 2.64; 95% CI: 1.54–4.59; P for trend < 0.001). The optimal NLR cutoff was 5.53, yielding an area under the receiver operating characteristic curve of 0.649 (95% CI: 0.599-0.700). Subgroup analyses demonstrated consistent associations across age, sex, atrial fibrillation status, and diabetes subgroups. Elevated admission NLR is independently associated with poor 90-day functional outcomes in LVO stroke patients undergoing EVT. NLR represents a simple, cost-effective, and readily available biomarker that may facilitate early risk stratification and guide clinical decision-making in this high-risk population.