Preoperative Peripheral Blood CD4/CD8 Ratio Predicts The Prognosis Of Patients With Coronary Atherosclerotic Heart Disease After Off-pump Coronary Artery Bypass Grafting

Objective:Off-pump coronary artery bypass grafting(OPCABG)is an effective myocardial revascularization technique as the treatment of coronary atherosclerotic heart disease(CAD),but the occurrence of major adverse cardiac events(MACE)after OPCABG affects the prognosis of patients seriously.Recent studies had shown that T lymphocyte subsets played an important role in the pathological process of CAD,and the CD4/CD8 ratio was closely related to acute adverse events in CAD patients.This study was aimed to investigate the relationship between preoperative peripheral blood CD4/CD8 ratio and the prognosis of patients after OPCABG,as well as the predictive value for postoperative MACE.Methods:The CAD patients underwent OPCABG in Cardiovascular Surgery Department of The First Affiliated of Anhui Medical University from September 2016to April 2017 were enrolled in the study.Baseline data,preoperative related results of laboratory test and medical imaging examination were collected.Peripheral blood samples were collected from patients before the operation to detect the levels of CD3~+CD4~+and CD3~+CD8~+T cells by flow cytometry(FCM),and CD4/CD8 ratio was calculated.All patients were divided into the high CD4/CD8 group(CD4/CD8?1.4)and the low CD4/CD8 group(CD4/CD8<1.4)according to CD4/CD8 ratio.Patients were followed up with the end point of occurrence of MACE after discharge,and the results were recorded.Kaplan-Meier analysis was used to compare the prognosis of two groups.And the predictive value of CD4/CD8 ratio for postoperative MACE was evaluated by receiver operating characteristic(ROC)curve.Cox proportional hazards model was applied to screen out the independent risk factors of postoperative MACE.And Nomogram to predict postoperative MACE was constructed by R-3.6.3 with the rms package.The internal validation and calibration curves were used to evaluate the predictive efficiency of the model.Results:A total of 118 patients with an average age of 62.74±4.50 years were enrolled in the study,including 82(69.49%)males.The average postoperative follow-up time of all patients was 23.25(20.91,24.70)months,during which 4 patients(3.39%)lost to follow-up and 21 patients experienced MACE.The incidence of postoperative MACE was 17.80%.In addition,the median preoperative CD4/CD8 ratio in peripheral blood of all patients was 1.40(1.00,2.07).The high CD4/CD8 group enrolled 62 patients,and 16(25.81%)patients experienced MACE.Among the 56 patients in the low CD4/CD8group,5(8.93%)patients experienced MACE.The incidence of postoperative MACE in the high CD4/CD8 group was higher than that in the low CD4/CD8 group(P=0.02).The results of Kaplan-Meier survival curve analysis showed that the MACE free survival rate in the high CD4/CD8 group was lower than that in the low CD4/CD8group,and the difference was statistically significant.The area under the ROC curve of CD4/CD8 ratio predicting postoperative MACE was 0.778(95%CI:0.661-0.894,P<0.01),the optimal cut-off value was 2.24,the sensitivity was 57.1%,and the specificity was 87.6%.Furthermore,the study entered postoperative potential risk factors and traditional cardiovascular risk factors into Cox proportional risk regression model.Univariate analysis showed that hs CRP(HR=1.085,95%CI:1.043-1.129,P<0.01),LVEF?50%(HR=5.690,95%CI:2.082-15.546,P<0.01)and CD4/CD8 ratio(HR=5.560,95%CI:2.819-10.969,P<0.01)were risk factors of postoperative MACE.The predicted variables in univariate analysis results with P<0.10(HDL-C,hs CRP,LVEF?50%and CD4/CD8 ratio)were screened out and included into Cox model again.The backward selection method(LR)was used for multivariate stepwise regression analysis.The results showed that CD4/CD8 ratio(HR=3.178,95%CI:1.608-6.281,P<0.01),hs CRP(HR=1.066,95%CI:1.017-1.117,P<0.01),and LVEF?50%(HR=3.242,95%CI:1.123-9.358,P=0.03)were independent risk factors for postoperative MACE.The Nomogram showed good discrimination for internal validation with C-index of 0.821(95%CI 0.725-0.971).The predictive calibration curves in 1 year and 2years for the Nomogram were consistent with actual situation.Conclusions:The incidence of middle-term MACE in CAD patients after OPCABG is about 17.80%.And preoperative elevated CD4/CD8 ratio in peripheral blood is an independent risk factor for postoperative MACE with good predictive value.