Prognostic Value of Neutrophil To Lymphocyte Ratio In Acute Ischemic Stroke Patients Treated With Intravenous Thrombolysis: A Meta-Analysis

Background: The neutrophil to lymphocyte ratio (NLR) has been shown to be an important independent inflammatory indicator in stroke. The relationship between NLR and poor prognostics in acute ischemic stroke (AIS) patients who received intravenous thrombolysis (IVT) still unclear. The purpose of this meta-analysis was to evaluate the association between NLR and poor prognosis after IVT. Furthermore, we aim to concluded whether admission NLR or post-IVT NLR play a role in AIS. Methods: : Pubmed, Embase, Wed of Science and China National Knowledge Infrastructure were searched for relevant articles until October 7, 2020. Cohort and case-control studies were included if related to NLR in AIS patients treated with IVT. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were pooled to estimate the relationship between NLR and poor prognosis after IVT. A random effects model was used to calculate the pooled data. Results: : Twelve studies, including 3641 patients met the predefined inclusion criteria. Higher NLR levels were associated with an increased risk of hemorrhagic transformation (HT) (OR=1.33,95%CI=1.14-1.56, P <0.001) and 3-month poor functional outcome (OR=1.64,95%CI=1.38-1.94, P <0.001) in AIS patients receiving IVT. Subgroup analysis of HT suggested that admission NLR levels rather than post-IVT NLR levels was associated with higher risk of HT (OR=1.33,95%CI=1.01-1.75, P=0.039). But There had no statistically significant difference between higher NLR levels and 3-month mortality (OR=1.14, 95%CI=0.97-1.35, P =0.120). Conclusions: : High NLR can predict HT and 3-month poor functional outcome in AIS patients received IVT. Admission NLR rather than post-IVT NLR was independent risk factor of increased risk of HT.