Research On The Relationship Between Preoperative Albumin Corrected Anion Gap And Hospitalization And Long-term Death Of Patients Undergoing Coronary Artery Bypass Grafting

Background and ObjectiveCoronary artery disease is a global health concern and one of the main causes of death.Till today,coronary artery bypass grafting(CABG)is still one of the main treatment strategies for coronary artery disease,especially for patients with multivessel cornary disease or complex coronary artery disease.It is very important to study preoperative related indexes and risk factors and take targeted treatment for the prognosis of such patients.Albumin corrected anion gap(ACAG)is an effective index to evaluate the prognosis of critically ill patients.Therefore,the present study was to explore whether preoperative ACAG could be used as an index to predict the postoperative death risk of patients undergoing coronary artery bypass grafting and the relationship between preoperative ACAG and hospitalization and long-term death of these patients.MethodThis study,a retrospective study,reviewed patients who were hospitalized for CABG treatment from January 1,2001 to December 31,2012 in the Medical Information Mart for Intensive Care III database.Firstly,by drawing ROC(receiver operating characteristic)curve,the optimal cutoff value of preoperative ACAG for predicting the death of patients undergoing CABG during hospitalization was determined,and then the patients were divided into two groups,and the baseline data characteristics,surgical types and outcomes of the two groups were compared based on the optimal cutoff value.Kaplan-Meier survival curve was constructed to compare the long-term survival rate between the two groups,and the log-rank method was used to compare the two groups.Binomial Logistic regression analysis and COX risk regression analysis were used to determine the correlation between preoperative ACAG and CABG patients’ hospitalization and death within 4 years.ResultsA total of 2180 CABG patients were included in this study.According to the ROC curve analysis,the optimal cutoff value of ACAG for predicting CABG patients’death in hospital before operation was 16mmol/L,thereby the patients were divided into high ACAG group(ACAG≥16.0mmol/L)and low ACAG group(<16.0mmol/L).There were obvious differences between the two groups in baseline data characteristics,admission laboratory examination,and types of simultaneous operations.Patients in the high ACAG group presented with longer length of stay in intensive care unit(3.88(2.15,7.09)vs 2.29(1.29,3.94),P<0.001),higher inhospital mortality(28(4.5%)vsll(0.7%),P<0.001)and 4-year mortality(125(27.1%)vs111(12.7%),P<0.001).Kaplan-Meier survival curve analysis showed that the 4-year survival rate of patients with high ACAG after CABG was significantly lower(P<0.001).The results of binomial logistic regression analysis showed that there was a good correlation between preoperative ACAG and postoperative hospital death of CABG patients(OR:1.248(1.060,1.470),P=0.008).The preoperative ACAG≥16mmol/L suggested that CABG patients had about 2.7 times the risk of hospital death(OR:2.732(1.129,6.610),P=0.026).COX risk regression analysis showed that there was a good correlation between preoperative ACAG and CABG patients’ four-year postoperative death(HR:1.134(1.063,1.210),P<0.001),but there was no significant correlation between preoperative ACAG≥16mmol/L and CABG patients’ four-year postoperative death(HR:1.198(0.873,1.643,P=0.263).ConclusionsPreoperative ACAG was an early and rapid risk assessment index for patients undergoing coronary artery bypass grafting.Besides,There was a good correlation between the increase of ACAG before operation and the increase of hospitalization and long-term death risk of these patients.