Study Of Relationship Between Systemic Immune Inflammation Index And Acute Stroke-associated Pneumonia And Stroke Prognosis

BackgroundStroke is the main cause of disability and death in the world.Ischemic stroke is the main type,accounting for 80%-85%of all kinds of stroke.Stroke-associated pneumonia(SAP)is one of the most common complications during the admission period of acute ischemic stroke(AIS)patients.It increases the mortality rate of patients with AIS and cause serious economic burden.Therefore,it is imperative to look for markers that may be associated with SAP and poor prognosis in AIS patients.At present,there are accumulating research evidences that inflammatory mechanism plays an important role in the development and outcome of ischemic stroke.Neutrophils,lymphocytes and other peripheral blood cells have been proved that related to prognosis of ischemic stroke and post-stroke infection in many reports.The systemic immune-inflammation index(SII),as a new type of economic research factor that combines three types of blood cells in the periphery of neutrophils,platelets and lymphocytes,has become a hot spot in recent years.At present,SII has been widely used in prognosis prediction of various tumor diseases.However,its research in AIS is still scarce.ObjectiveThe purpose of this study was to investigate the relationship between S? and SAP,and further analyze the value of this value in predicting the prognosis of AIS patients.Methods1.This study is a prospective cohort study:prospectively included AIS patients who were admitted to the First Affiliated Hospital of Zhengzhou University within 24 hours from January 2015 to December 2017,collected patient demographic characteristics and clinical data,and selected patients for admission blood samples were measured routinely within 24 hours,and the SII value(×109/L)was calculated,S?=P(×109/L)× N(×109/L)/L(×109/L),where P,N and L is the count of peripheral platelets,neutrophils and lymphocytes,respectively.The study outcomes include:whether SAP occurred during admission and the prognosis in March and 1 year.2.Correlation analysis between S? and SAP:SPSS24.0 is used for data analysis.Use single factor and multi-factor Logistic regression to analyze the relationship between S? and SAP.Receiver operating characteristic(ROC)curve was used to evaluate the predictive value of S? to SAP.3.Correlation analysis of the prognosis of S? and AIS patients:the prognostic outcome indicators were evaluated using modified rankin scale(mRS),including moderate to severe disability(mRS 3-5 points),death(mRS 6 points)and combined Poor prognosis(mRS 3-6 points).SPSS24.0 and MedCalc.19.04 software were used for data analysis.Univariate and multivariate logistic regression were used to analyze the relationship between S? and the prognosis of AIS patients at 3 months and 1 year.The ROC curve was used to evaluate the predictive value of S? on the prognosis of AIS patients.The application of MedCalc.19.04 software used the Delong test to compare the difference between the baseline NIHSS single index and the combined index of SII+NIHSS for the predictive outcome of AIS patients.Kaplan-Meier curve was used for survival analysis,and Log-Rank method was used for testing.All statistics were tested using a two-sided test,P<0.05 was considered statistically significant.Results1.S? was grouped according to tertiles,and take the low tertile S? group as a reference.Multivariate logistic regression analysis shows that the high tertile SII group is related to SAP(P<0.001).The area under the curve(AUC)of the ROC curve is 0.762(95%CI 0.736-0.787;P<0.001).When the SII is at the optimal cutoff point 901.06,the SAP is predicted to have a sensitivity of 68.67%and a specificity of 78.00%.2.In March and 1 year follow-up,adjusted for age and gender,multivariate logistic regression analysis showed that the high tertile S? group was associated with moderate and severe disability,death,and combined poor prognosis(P<0.001);adjusted for age and gender,Previous medical history,baseline NHISS and other risk factors,multivariate logistic regression analysis showed that the high tertile SII group was still associated with death and combined poor prognosis(P<0.05),but no statistically significant correlation with moderate and severe disability(P>0.05).3.ROC curve analysis showed that S? predicted higher mortality in March(AUC=0.765)than in March predicted moderate and severe disability(AUC=0.557)and combined poor prognosis(AUC=0.612);similarly,SII predicted 1-year death(AUC=0.725)is also higher than the prediction of 1-year moderate and severe disability(AUC=0.575)and combined poor prognosis(AUC=0.662).4.The difference between SII and NIHSS in predicting death in March(0.783 vs 0.756;P=0.088)is not statistically significant after the combined use of NIHSS scores,but from a trend perspective,the predictive value is better.There is a statistical difference between the prediction of one-year death(0.758 vs 0.732;P=0.0437).5.Kaplan-Meier survival curve showed that the survival rate of the group with higher S? value(S?? 887.25 × 109/L)was lower than that of the group with lower S? value(P<0.0001).Conclusions1.Admission S? value is an independent risk factor for SAP.2.Admission S? value can predict early and long-term prognosis of AIS patients.Higher S? value indicates greater risk of poor prognosis.Compared with moderate to severe disability and combined poor prognosis,S? predicts early and long-term death better.3.When the S? value and the NHISS score are combined,the predicted death is better than that of a single NHISS.