Risk Factors Analysis And Prediction Model Construction Of Acute Kidney Injury After Acute Type A Aortic Dissection Operation

Background and ObjectiveAcute type A aortic dissection(ATAAD)is a complex emergency that seriously threatens patients’ lives and has a poor natural prognosis.Surgical treatment is mainly used for ATAAD,but itself can tear important branch blood vessels and cause hypoperfusion of organs,as well as strong stress response caused by surgical trauma,the incidence of postoperative complications remains high.Acute kidney injury(AKI)is one of the common complications after ATAAD operation,and the incidence is significantly higher after aortic surgery than other types of cardiac surgery.However,the different diagnostic criteria lead to large differences in the incidence of AKI.AKI is recognized as an independent risk factor for predicting patient death,so maximal restoration of renal function is the goal of AKI prevention and treatment.So far,there is still no specific drug treatment for AKI in addition to renal replacement therapy.Early identification and intervention,correcting reversible factors,optimizing vascular volume status,maintaining hemodynamic stability,and reasonable nutritional support treatment are still the main contents of postoperative AKI clinical management.Therefore,exploring the risk factors of AKI after ATAAD operation,early identifying high-risk patients and adopting comprehensive management strategies are of great clinical significance to control the occurrence and development of postoperative AKI and improve the prognosis of ATAAD patients.Based on this,this study analyzes the relevant risk factors of AKI after ATAAD operation and establishes a postoperative AKI prediction model to provide an objective basis for better guiding clinical work.Materials and methodsSelecting ATAAD patients who underwent cardiovascular surgery at the Second Affiliated Hospital of Zhengzhou University from June 2016 to February 2019.A total of 112 patients are included in the study according to the inclusion and exclusion criteria.All patients are diagnosed with aortic CTA before surgery.Collecting relevant clinical data of 112 patients,including preoperative data[age,gender,weight,previous history,renal artery involvement,left ventricular ejection fraction(LVEF)and hemoglobin(Hb),serum creatinine(SCr),neutrophil-to-lymphocyte ratio(NLR),C-reactive protein(CRP),etc],surgical data[surgery method,cardiopulmonary bypass(CPB)time,deep hypothermia circulatory arrest(DHCA)time,aortic occlusion time,surgical time and intraoperative red blood cell infusion volume,etc.]and postoperative data(ventilator assisted breathing time,ICU stay time,hospitalization time and hospital mortality,etc.).According to whether acute kidney injury occurrs after surgery,112 patients are divided into acute kidney injury group(AKI group)and control group(Non-AKI group).SPSS statistics 24.0,medcalc 19.1 and R 3.6.2 are used to analyze the data.Firstly,the clinical data of the two groups of patients are analyzed by single factor,and the statistically significant indicators are selected to be included in multivariate Logistic regression analysis.According to the multivariate Logistic regression analysis,a prediction model is established.Drawing the receiver operating characteristic curve(ROC)to evaluate the prediction model,and using the Hosmer-Lemeshow test to evaluate the goodness of fit of the prediction model.Using R 3.6.2 software to draw the nomogram of predicting AKI after ATAAD operation.Bootstrap self-sampling method is used for internal verification,and C-index is used to evaluate the accuracy of the nomogram.The calibration curve is a graphic comparison between the predicted results and the actual results.The better the fit between the calibration curve and the ideal curve is,the higher the prediction accuracy of the nomogram is.Results(1)Univariate analysis shows that there are significant differences between the two groups in hypertension,renal artery involvement,preoperative SCR,preoperative NLR,CPB time,DHCA time,aortic occlusion time,operation time,intraoperative red blood cell infusion volume and ventilator-assisted breathing time(P<0.05).(2)Multivariate Logistic regression analysis shows that hypertension,renal artery involvement,CPB time,and ventilator-assisted breathing time are independent risk factors for AKI after ATAAD operation.Four groups of variables are included in the regression model,and the regression equation was established as Logit(P)=-15.041+1.440 × hypertension+1.675 × renal artery involvement+0.032 × CPB time+0.030 × ventilator-assisted breathing time.(3)The AUC of the Logistic regression model was 0.926(95%CI=0.861-0.967,P<0.001).The optimal cut-off point is 0.45,at which the sensitivity is 82.6%and the specificity is 87.9%.Hosmer-Lemeshow test shows that P=0.733,indicating that the model owns good goodness-of-fit.(4)According to the nomogram established by hypertension,renal artery involvement,CPB time and ventilator-assisted breathing time,the score of hypertension is 74 points,renal artery involvement is 69 points,and CPB time>213min is 97 points,and the ventilator-assisted breathing time>70h is 100 points.The final total score is obtained by adding all individual scores.The corresponding value of the total score is the probability of predicting AKI by the nomogram model.The bootstrap self-sampling method is used for internal verification.It is found that the nomogram has good accuracy and differentiation,and the C-index is 0.859(95%CI=0.788-0.930).Conclusions(1)AKI after ATAAD operation is associated with many risk factors,including hypertension,renal artery involvement,preoperative SCr,preoperative NLR,CPB time,DHCA time,aortic occlusion time,surgical time,intraoperative red blood cell transfusion volume,ventilator-assisted breathing time.Among them,hypertension,renal artery involvement,CPB time and ventilator-assisted breathing time are the independent risk factors.(2)The Logistic regression model established in this study is more effective in the diagnosis of AKI after ATAAD operation,and the probability of AKI can be more intuitively understood through the nomogram,which provides some basis for guiding clinical work.