To Investigate The Relationship Between Preoperative Mean Corpuscular Volume And Contrast Induced Nephropathy After Percutaneous Coronary Intervention

Background: Contrast induced nephropathy(CIN)is an acute kidney injury that occurs in 2 or 3 days after using contrast medium,without other renal damage factors.With the widely application of contrast media in modern imaging and interventional therapy,the incidence of CIN is becoming increasingly common,and gradually increases to the third leading cause of hospital acquired acute renal failure.Already known risk factors for CIN include chronic kidney disease(CKD),diabetes mellitus(DM),hypovolemia,the application of nephrotoxicity drugs,such as aminoglycoside,the instability of hemodynamic,the application of intra-aortic balloon counterpulsation,and so on.In the study of contrast induced nephropathy,its pathogenesis mainly includes: hemodynamic factors,renal medullary ischemia,renal tubular injury,renal tubule occlusion,apoptosis,oxygen free radical damage,immune factors,contrast agent on renal tubular toxicity.Renal medullary ischemia and hypoxia is one of the most important pathogenesis of CIN(5).As the carrier of oxygen,red blood cells play an important role in the oxygen supply and demand balance of kidney,and then affect the renal function.The majority of studies have shown that anemia may promote the occurrence of contrast induced nephropathy.Because it aggravates renal ischemia and hypoxia,which can damage renal function.However,three common red blood cell indexes in clinic are cytometry,hemoglobin content and mean corpuscular volume.There are few studies on the correlation between preoperative mean corpuscular volume and CIN after PCI and the relationship between them is not clear.Objective: To investigate the correlation between preoperative mean corpuscular volume(MCV)and contrast induced nephropathy(CIN)after percutaneous coronary intervention(PCI).It may provide a way to prevent the occurrence of contrast induced nephropathy for CIN high-risk groups,Methods:The subjects of this study were 300 patients with coronary heart disease who underwent PCI in our hospital from January to December of 2016..The general situation of the selected patients,past medical history,current medical history,medication history,allergic history,preoperative routine examination were recorded.The time for blood extraction is the second day without eating.Blood examination were used in emergency laboratory Backman blood cell analyzer(MCV normal range of 82-100fl).The patients were hydrated with 0.9 percent saline intravenously at a rate of 1 ml per kilogram of body weight per hour beginning 4 hours before the scheduled angiography,then started to PCI in the Department of Cardiology of the catheterization laboratory,and continued to hydrate 24 hours after PCI,and rechecked the patient's renal function at postoperative 48 hours.Computered the incidence of contrast induced nephropathy according to the current diagnostic criteria for contrast induced nephropathy.The patients were divided into contrast group(CIN group)and non contrast nephropathy group(non CIN group).Observe the clinical features between the two groups,to find the relative risk of contrast nephropathy factors,and the correlation between the average red cell volume and contrast induced nephropathy.The ROC curve is used to obtain the best prediction value of MCV to CIN.MCV was divided into two groups according to the ROC value,and the incidence rate of CIN in the two groups was compared between the groups.Data analysis using SPSS 21.0 statistical software.Categorical Continuous variables were expressed as the mean value ± standard deviation(SD)or median(inter-quartile range);ategorical variables were summarized as percentages.The two samples were compared by t test or rank-sum test.The incidence of CIN was compared by the chi-square test.Using single factor Logistic regression analysis to find the risk factors which may cause contrast nephropathy,Using Logistic regression analysis to explore the correlation between preoperative CIN and the average volume of red blood cells occurred.ROC curve is used to obtain the best prediction value of MCV for CIN.P<0.05 was considered statistically significant.Results:1 CIN group has 19 patients,and non CIN group has 281 patients.There is significantly difference between CIN group and non CIN group in the age,preoperative mean corpuscular volume(P<0.05);The clinical baseline characteristics such as gender,height,weight,albumin,phemoglobin level,total cholesterol,reoperative fasting blood glucose,smoking history,hypertension,diabetes,hyperlipidemia and acute myocardial infarction history,the use of drugs,like statin,ACEI/ARB,LVEF%,contrast agen type and dosage,Operation path,ejection fraction and so on were not significantly different between the two groups.(P>0.05).2 Logistic regression analysis showed that the types of contrast media and preoperative MCV levels were correlated with the incidence of contrast induced nephropathy.Preoperative MCV level was the independent predictor of CIN,as well as other known risk factors.3 ROC curve: according to the ROC curve,91.95 fl is the best predictor of the occurrence of CIN in MCV.Its sensitivity was 0.63,specificity was 0.684,and the area under the ROC curve was 0.642.4 According to the ROC value,the MCV group was divided into two groups.The high MCV group has 179 patients,and low MCV group is 121 cases.There is significantly difference between high MCV group and low MCV group in the gender and smoking history.(P<0.05);The clinical baseline characteristics such as age,height,weight,fasting blood glucose,hemoglobin level,hypertension,diabetes,hyperlipidemia,acute myocardial infarction,the use of drugs,like statin,ACEI/ARB,contrast agent type and dosage,LVEF% and so on were not significantly different between the two groups.(P>0.05).5 Comparison of the incidence of contrast induced nephropathy between the high levels MCV group and the low levels MCV group.The incidence of CIN is 10.7% in high levels MCV group,the incidence of CIN is 3.4% in low levels,and incidence of CIN in two groups were statistically significant(P=0.01).The incidence of contrast induced nephropathy in low levels of MCV was higher than MCV group with high.Conclusions:When hemoglobin is in the normal range,the preoperative mean corpuscular volume(MCV)is related to CIN.Mean corpuscular volume decreased as one of the risk indicators of CIN,can be used as a predictive factor in CIN.According to the ROC curve,91.95 fl is the best predictor of the occurrence of CIN in MCV...