The Predictive Value Of Neutrophil/lymphocyte Ratio At Different Time Points For Clinical Outcome After Mechanical Thrombectomy

Background and purpose:Stroke is the leading cause of death and disability in China,among which ischemic stroke accounts for 70%.At present,the treatment options for ischemic stroke mainly include intravenous thrombolysis and endovascular mechanical thrombectomy.In recent years,endovascular treatment has been gradually developed,and the rate of implementation in hospitals has been greatly increased.However,there are still clinical results such as postoperative hemorrhagic transformation or malignant cerebral edema after endovascular treatment,which have a great impact on the outcome of patients’ diseases.Therefore,it is of great clinical significance to explore biomarkers for predicting relevant clinical outcomes,and to prevent and treat them in the early stage.Previous studies have also explored the relationship between neutrophil-lymphocyte ratio(NLR)and clinical outcomes.However,most of the previous studies focused on intravenous thrombolysis,while few studies on Endovascular Treatment(EVT),and most of them only focused on NLR at admission.Therefore,this study aims to explore the predictive value of neutrophil/lymphocyte ratio at different time points for clinical outcomes after EVT.Methods:A total of 168 acute ischemic stroke patients with anterior circulation occlusion who underwent direct mechanical thrombectomy or bridging thrombectomy in Taizhou People’s Hospital from October 2019 to April 2022 were retrospectively enrolled.All patients underwent head CTA+CTP examination in the emergency department,and the neutrophil and lymphocyte counts were detected by blood cell analyzer.The NLR at admission was recorded as NLR0,and the NLR at each time point after mechanical thrombectomy was collected and calculated.The NLR within 24 hours after operation was recorded as NLR1,and the maximum NLR within 7 days was recorded as NLR2.Postoperative imaging was used to determine the relevant clinical results such as postoperative hemorrhagic transformation and malignant brain edema,and the prognosis of patients was determined by 90 days telephone follow-up.Multivariate binary logistic regression analysis was used to explore the potential adverse factors affecting prognosis,and the Receiver operating curve(ROC)was used to analyze the predictive value of NLR in different periods for prognosis.Secondly,the predictive value of NLR0 and NLR1 for hemorrhagic transformation and malignant brain edema was analyzed by ROC curve.Results:A total of 168 patients with acute ischemic stroke who received endovascular treatment were enrolled,of which 95(56.5%)had poor prognosis.P<0.05 was included in the binary multivariate logistic regression analysis model.By constructing two models NLR1 and NLR2 are independent risk factors for poor prognosis.Model 1showed that the third percentile NLR1(OR=3.279,95%CI: 1.158-9.286)was approximately 3.3 times of the first percentile NLR1 for poor prognosis.Model 2showed that the third NLR2(OR=8.881,95%CI: 2.80-28.16)was about 8 times more likely to have poor prognosis than the first NLR2.The two models also showed that the occurrence of malignant cerebral edema,increased NIHSS score,and poor collateral circulation were independent risk factors for poor prognosis.According to the ROC curve analysis of NLR in different periods of time,when the optimal cut-off value of NLR1 was 10.145,the area under the curve was 0.751(95%CI: 0.678-0.824),the sensitivity was 74.7%,and the specificity was 68.5%.When the optimal cut-off value of NLR2 was 12.285,the area under the curve was 0.832(95%CI: 0.769-0.896),the sensitivity was 77.9%,and the specificity was 82.2%.We also analyzed the predictive value of NLR0 and NLR1 for clinical events,and found that in the ROC curve of postoperative Parenchymal hemorrhage(PH),when NLR1 was the best cut-off value of14.09,the area under the curve was 0.765.(95%CI:0.669-0.862),the sensitivity was77.4%,and the specificity was 71.5%.logistic regression analysis showed that the incidence of PH in the third quantile NLR1(OR=6.17,95%CI: 1.63=26-23.42)was about 6 times higher than that in the first quantile NLR1(OR=6.17,95%CI:1.63=26-23.42).Conclusions:NLR within 24 hours and maximum NLR within 7 days after mechanical thrombectomy are independent risk factors for poor prognosis at 90 days after mechanical thrombectomy.Among them,when NLR1>10.145,the poor prognosis rate increased significantly,and the area under the curve was 0.751.The prediction ability of the maximum NLR within 7 days was better when NLR2>12.285,the poor prognosis rate was significantly increased,and the area under the curve was 0.832.In addition,the occurrence of malignant cerebral edema,increased NIHSS score,and poor collateral circulation were also independent risk factors for poor prognosis.In addition,NLR1 has a certain predictive value for PH after mechanical thrombectomy,when NLR1>14.09,the incidence of PH increased greatly,with an area under the curve of 0.765.As a biomarker,NLR has shown considerable predictive value for prognosis and various clinical events.