Multivariate Analysis Of Hemorrhagic Transformation After Endovascular Therapy Inacute Ischemic Stroke Of Anterior Circulation

Objective:To explore the influencing factors of hemorrhagic transformation after endovascular therapy in acute ischemic stroke of anterior circulation and establish a prediction model.Methods:The clinical and imaging data of patients with anterior circulation acute ischemic stroke(AIS)treated in the Chongqing University Three Gorges Hospital from November 2020 to November 2021 were collected.All patients completed multimodal CT examination and obtained non-contrast CT(NCCT),CT angiography(CTA)and whole brain CT perfusion(CTP)images.cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time(MTT),time to peak(TTP),time to maximum(Tmax)and surface permeability(PS)in ischemic area and contralateral mirror area were measured,and calculate the relative values according to the ischemic hemisphere/healthy hemisphere to obtain rCBF,rCBV,rMTT,rTTP,rTmax and rPS.NCCT and CTP images were analyzed by RAPID software to obtain ASPECTS score,infarct core volume,Tmax>6s brain tissue volume,hypoperfusion index ratio(HIR)and CBV Index.The collateral circulation was evaluated by multiphase CTA collateral circulation score,and the correlation between HIR,CBV Index and collateral circulation was discussed.All patients completed CT or MRI reexamination within 1 week of symptom onset and divided into hemorrhagic transformation(HT)group and non-HT group according to the reexamination results.The clinical and imaging data of the two groups were compared and analyzed.Results:The study included 68 patients who met both inclusion and exclusion criteria,including 28 in HT group in which 7(25.0%)patients with good collateral circulation;In the non-HT group,there were 40 cases in which 27 cases(67.5%)had good collateral circulation.HIR was negatively correlated with collateral circulation;CBV Index was positively correlated with collateral circulation.The collateral circulation of HT group was worse than that of nonHT group,and the NIHSS score and proportion of adverse functional outcomes at day 90 were higher than that of non-HT group(P<0.05).The infarct core volume,Tmax>6s volume,HIR,MTT,PS,Tmax,rTTP,rMTT,rPS and rTmax in HT group were larger than those in non-HT group,and the ASPECTS score,CBV Index,CBV,CBF,rCBV and rCBF were smaller than those in non-HT group(P<0.05).LASSO regression analysis showed that collateral circulation,NIHSS score,ASPECTS score,infarct core volume,PS and rPS were the predictors of HT.Binary logistic regression showed that high NIHSS score,high rPS and poor collateral circulation were the risk factors of HT.The prediction formula was logit(P)=0.152×NIHSS+0.155×rPS=1.563×collateral circulation-3.227.The area under curve(AUC)of the formula is 0.891(95%CI:0.803～0.979),the sensitivity is 0.857 and the specificity is 0.825.Conclusions:HIR combined with CBV Index can better reflect the collateral circulation of patients with anterior circulation large vessel occlusion.The HT after endovascular treatment of anterior circulation AIS is affected by many factors.For patients with high baseline NIHSS score,high rPS and poor collateral circulation after admission,the possibility of HT after endovascular treatment should be highly vigilant.