The Clinical Study To Assess The Perioperative Risk Of Carotid Stent Implantation

Study background and objective:With improvement of living standard and aging of population,cerebral stroke incidence has increased year by year and fatality rate and disability rate of stroke are high,which brings a heavy economic burden to families and the society.Stroke caused by atherosclerotic stenosis of internal carotid accounts for 10-15%.At present,there are two main methods for treatment of internal carotid atherosclerotic stenosis : Carotid endarterectomy(CEA)and carotid artery stenting(CAS).In a random trial comparing CAS and CEA for symptomatic carotid stenosis,CAS has a higher risk of operation-related stroke.Related studies have also reported that severe or disabling stroke or death caused by internal carotid artery stenting mainly occurred during the perioperative period.A large number of previous studies have reported that the incidence of CAS perioperative complications is related to many factors.such as: a patient's baseline characteristic,stenotic lesion characteristic,operative approach factor,surgical procedure and material factor.At present,foreign studies have reported that there are 5 CAS risk assessment systems to quantify these relevant factors so as to assess perioperative risks before CAS operation:1.Post-CAS DWI new embolization infarct focus risk scoring system;2.Scoring system for pre-CAS prediction of all-cause mortality risk in asymptomatic carotid stenosis patients within 3 years;3.CHAS scoring system;4.BRASS risk scoring system;5.Siena CAS risk scoring system.All the above CAS risk assessment systems are the conclusions of foreign single center clinical research.At present,China does not have a CAS risk scoring system applicable to its own.Can we learn from foreign risk scoring systems to demonstrate their accuracy,sensitivity and specificity in Chinese CAS population?By comparing the five CAS risk assessment systems,we found that the Siena CAS risk scoring system was the most comprehensive,covering all factors related to the risk of occurrence of CAS perioperative complications,However,it is more complicated in clinical application.The CHAS scoring system has only four related factors,so its clinical application is relatively simple and clear,but its evaluation is not comprehensive enough.To choose the best scoring system,we should consider choosing the risk system wi th the best accuracy,sensitivity and specificity.Therefore,we intend to conduct a retrospective study of the Siena CAS risk score system and CHAS risk score system in a single center to compare the accuracy,sensitivity and specificity of the two risk score systems in predicting the perioperative risk of carotid artery stenting patients in our hospital.We find a perioperative risk scoring system more suitable for CAS population in our hospital,and hope to further improve the accuracy,sensitivity and specificity of the risk scoring system in predicting perioperative risk of CAS population in our hospital through this study.Study objects and methods:1.Study objectThis is a retrospective study,We collected patients who received CAS treatment in the clinical stroke center of xinqiao hospital from June 2014 to November 2017 according to the admission criteria.2.Research method(1)Patients were divided into the stroke group and the non-stroke group according to whether there was a stroke in the 30 days after CAS;(2)According to the Siena CAS scoring system,the Siena CAS score of each patient was calculated and divided into low risk,medium risk and high risk groups.Statistical analysis was conducted to determine whether there were statistical differen ces in the incidence of perioperative stroke among the three groups of CAS patients;(3)According to the Siena CAS score,the ROC curve was drawn to determine the accuracy,specificity and sensitivity;(4)The risk score of each patient was calculated according to the CHAS scoring system,and the perioperative stroke incidence of patients with different CHAS scores was statistically analyzed;(5)ROC curve was drawn according to CHAS score to clarify accuracy,specificity and sensitivity;(6)Based on the analysis of single factor and multi-factor logistic regression models,independent predictors of the perioperative risk of CAS were further found;(7)The accuracy,specificity and sensitivity of predicting the perioperative risk of CAS with multiple independent predictors were determined by drawing a ROC curve based on the combination of multiple independent predictors.The Siena CAS risk score system alone and multiple independent predictors of CAS perioperative risk were compared to evaluate the risk of CAS perioperative period.(8)Further statistical analysis of stroke incidence in CAS patients with different age groups and different fasting glucose levels.3.Statistical analysesData were expressed as mean and SD or were expressed as absolute frequency and percentage.Correlation between clinically relevant factor variables and stroke was assessed by t-test(measurement data)or chi-square test(enumeration data).Univariate logistic regression model and multivariate logistic regression model were used to analyze the correlation between the incidence of stroke and related factors within 30 days after CAS.Sensitivity and specificity of Siena CAS risk assessment system were reflected by drawing a ROC(receiver operating characteristic)curve.P<0.05 was considered to be statistically significant.All statistical analyses were performed using SPSS software version 22.0(IBM,Armonk,USA)Or Med Calc Software version 19.0.7(Med Calc Software,amazon,USA)and all graphs were made using Graph Pad Prism software version 7.02(Graph Pad software Inc.,San Diego,CA,USA)or SPSS software version 22.0(IBM,Armonk,USA).Results:1.A total of 425 patients were collected in this study,and found that 24 patients did not meet the criteria.Finally,401 CAS patients were collected for statistical analysis.Eighteen patients were complicated with stroke within 30 d after CAS,with stroke incidence of 4.5%,and 383 patients had no complication,accounting for 95.5%.2.Baseline characteristics of CAS patients in this study: mean age 65.9±9.4 years;Age > 80 years old accounted for 2.5%;Males accounted for 84.8%;Symptomatic patients accounted for 46.6%;Fasting blood glucose(FBG)> 7.1mmol/L accounted for 6.7%.Pathological vascular features: severe stenosis accounted for 90%;Ulcer plaques accounted for 20.4%;Calcified plaques accounted for 37.2%;Open lesions accounted for 57.4%;Lesion length ?15mm accounted for 30.4%;Internal carotid artery contortions accounted for 8.2%.Related factors during operation: use of protective devices accounted for 99.5%;35.2 percent pre-expansion;Closed-loop support accounted for 9%;Open-ring bracket 78.1%;Hybrid stents accounted for 13%;Type III bows account for 14%;Operation time less than 15 minutes accounted for 38.9%;15 to 30 minutes accounted for 27.7%;30 to 45 minutes accounted for 17.5%;More than 45 minutes accounted for 16%;Surgical experience < 50 cases accounted for 22.4%;Surgical experience of 50 to 100 patients accounted for 14%;The surgical experience of 100 to 150 patients accounted for 29.9%;Surgical experience of more than 150 patients accounted for 33.7%.3.The average score of Siena CAS in the stroke group(19.08±6.24)was significantly higher than that in the non-stroke group(13.13±6.61),and the difference was statistically significant(P < 0.001).4.The incidence of stroke in the low-risk group(0.0%)was significantly lower than that in the moderate-risk group(3.0%),and that in the moderate-risk group(3.0%)was significantly lower than that in the high-risk group(9%).There was a statistically significant difference in the incidence of stroke between the three groups(P < 0.003).5.The Siena CAS score predicted the perioperative risk of CAS with 53.3% specificity,83.3% sensitivity and 0.743 accuracy(AUC: 0.743,95%CI: 0.638-0.848).6.CHAS score was 0:11 in 6 patients,accounting for 28.9%.2 patients had stroke,and the incidence of stroke was 1.7%.The score was 1:18 cases,accounting for 47.1%;12 patients had stroke,with a stroke incidence of 6.3%.The score was 2:85,accounting for 21.2%.4 patients had stroke,with a stroke incidence of 4.7%.The score was 3:11 cases,accounting for 2.7%,0 patients had stroke,and the stroke rate was 0%.The score was 4:0.There was no significant difference in stroke incidence among the five groups(P=0.343).7.ROC curve was drawn according to CHAS risk score,with specificity of 29.8%,sensitivity of 88.9% and accuracy of 0.561(AUC: 0.561,95%CI: 0.449-0.674).8.Single-factor logistic regression analysis showed that Siena CAS score,FBG > 7.1mmol/L,and age > 80 years were significantly correlated with the incidence of stroke within 30 days after CAS surgery(P < 0.001,OR value 1.140,95%ci: 1.059-1.226;P < 0.014,OR value 4.472,95% CI: 1.363-14.677;P < 0.033,OR value 5.859,95% CI: 1.150-29.854).9.Multivariate logistic regression model analysis showed that Siena CAS score,FBG > 7.1mmol/L,and age > 80 years were significantly correlated with the incidence of stroke within 30 days after CAS surgery(P < 0.001,OR value 1.141,95%ci 1.056-1.234;P < 0.031,OR value 3.929,95% CI: 1.132-13.629;P < 0.017,OR value 8.106,95% CI: 1.453-45.236).10.In this study,combined with Siena CAS risk score,age and fasting blood glucose,the area under the ROC curve was 0.917,the sensitivity was 100%,and the specificity was 71.8%.The area under the ROC curve drawn by Siena CAS score was significantly higher than 0.743,with a specificity of 53.3 percent and a sensitivity of 83.3 percent.The area difference under the two ROC curves was 0.174,which was statistically significant(P=0.0011).Therefore,the accuracy,sensitivity and specificity of the prediction of perioperative risks of CAS with Siena CAS score,age and fasting blood glucose were improved by 0.174,16.7% and 18.5% respectively,which were significantly better than the prediction of perioperative risks of CAS with Siena CAS score alone.11.Incidence of stroke in the 21-40 age group: 0%;41-60 year old group: 3.1%;61-80 year old group: 4.5%;Group aged 81-100:20.0%.There was no statistically significant difference in the incidence of stroke among the four groups(P=0.103).However,the incidence of stroke in the fasting blood glucose group(14.81%)was significantly higher than that in the fasting blood glucose group(3.74%).The difference in the incidence of stroke between the two groups was statistically significant(P=0.026).Conclusion:1.The higher the Siena CAS score or the higher the risk stratification among CAS population in our hospital,the higher the incidence of stroke within 30 days after CAS surgery.2.Siena CAS risk scoring system is basically suitable for preoperative risk assessment of patients undergoing CAS in our hospital,with specificity of 53.3% and sensitivity of 83.3%,However,sensitivity,accuracy and specificity need to be further improved.3.Although CHAS risk score system is simple,there is no significant correlation between CHAS risk score and CAS perioperative stroke incidence in this study,and ROC curve of CHAS score shows AUC0.561,The AUC around 0.5 has no practical significance.4.We further found that Siena CAS risk score,FBG > 7.1mmol/L,and age > 80 years were independent predictors of perioperative risk of CAS.5.We found that the accuracy of combining Siena CAS risk score,age,and fasting glucose in predicting the perioperative risk of CAS patients in our hospital was 0.917,with a sensitivity of 100% and a specificity of 71.8%,significantly better than that of Siena CAS risk score alone.