The impact of inflammatory markers on clinical outcomes in acute ischemic stroke patients following mechanical thrombectomy: A multicentre study

BACKGROUND: Inflammation contributes to brain injury in acute ischemic stroke, but its role among patients treated with mechanical thrombectomy (MT) for large vessel occlusion (LVO) has not been fully established. The aim of this study was to explore the relationship between functional prognosis and the neutrophil-to-lymphocyte ratio (NLR) and derived ratios in patients undergoing MT. METHODS: This is a multicentre retrospective analysis of 970 consecutive patients treated with MT. Blood samples were collected on admission and after 24 h. Logistic regression was performed to assess the relationship between the ratios and 90-day modified Rankin scale (mRS) 0-2. Receiver-operating-characteristic (ROC) curves were used to estimate the ability of NLR and other ratios to predict the outcome. Restricted-cubic-spline (RCS) was used to investigate the association between NLR and 90-day mRS 3-6 and to determine a critical threshold. RESULTS: The 24-h NLR showed the strongest predictive performance (AUC = 0.670 alone; AUC = 0.784 when combined with other clinical variables) in patients treated with MT. An optimal NLR cutoff of 4.30 was identified, with patients below this threshold less likely to have poor 90-day outcome (RR 0.76 [95 % CI 0.65-0.89] p = 0.001) and significant shift toward better 90-day mRS scores (cOR 0.55, 95 %CI 0.40-0.74; p < 0.001). Restricted cubic spline analysis confirmed the cutoff's significance in predicting unfavourable mRS shifts. CONCLUSIONS: This study highlights the 24-h NLR as a powerful predictor of stroke outcomes post-MT, with a threshold of 4.30 strongly associated with poor prognosis. These findings suggest that NLR can guide personalized treatment approaches to improve recovery trajectories.