Effects Of Furosemide On Preventing Contrast-induced Nephropathy In High Risk Patients According To Brain Natriuretic Peptide Levels

ObjectiveTo investigate the effects of furosemide on preventing contrast-induced nephropathy(CIN)in high risk patients according to brain natriuretic peptide levels,and respectively compare it with the effects of simple hydration and furosemide combined with hydration.Methods1.Study objects: 160 patients who came to the Cardiology Department of the First Affiliated Hospital of Zhengzhou University undergoing coronary angiography from July 2015 to June 2016 were enrolled in this study.Among which 78 cases were male(48.75%)and 82 cases were female(51.25%).The average age was(62.14+ 8.39)years old.Inclusion criteria: 1).18 years or older;2).Undergoing CAG;3).Patients with chronic renal insufficiency,whose baseline estimated glomerular filtration rate was(15-90)ml/min/1.73m2;4).Patients who signed informed consent.Exclusion criteria: 1).Patients who died during operation.2).Patients with end-stage renal failure who required dialysis or after cardiac and renal transplantation.3).Patients who had a history of acute infectious diseases or contacted radioactive contrast agent in 72 hours before or 72 hours after operation.4).Acute decompensated heart failure.5).Thrombus in left ventricular.6).Allergic to radioactive contrast agents.7).Pregnant and lactating women.8).With malignant tumor or life expectancy less than 1 year.9).With valvular heart disease or undergoing surgery.10).With electrolyte disorder.11)Patients who had IV-grade cardiac function or obvious edema which are not suitable for hydration.2.Study methods: 160 patients undergoing CAG were randomly divided into three groups,among which 52 cases in control group,54 cases in furosemide group,and 54 cases in furosemide combined with BNP group.All the patients in three groups received 1ml/kg/h saline hydration from 12 hours before operation to 12 hours after operation,then they were checkd serum BNP level just after operation.Patients in control group received no management,and patients in furosemide group were intravenously injected 20 mg furosemide.For the patients in furosemide combined with BNP group,if BNP level was higher than 100pg/ml or higher than half of the baseline level,he or she received 20 mg furosemide,otherwise without any management.Before operation,we made a record of age,gender,height,weight,ejection fraction,serum creatinine(Scr),complication and the combined medication of every patient.The Creatinine Clearance was calculated according to the Cockcroft-Gault formula: Ccr(ml/min)=(140-age)*weight*1.23(*w*0.85 female)/Scr.The estimated glomerular filtration rate was calculated according to the simplified MDRD formula: eGFR = 186*(Scr)-1.154*(age)-0.203(×0.742 female).After operation,the CAG results were recorded.After 72 hours of operation,all the patients were checked Scr,then calculated Ccr and eGFR.The diagnostic criteria of CIN: An increase in serum creatinine of at least 0.5 mg/dl or to at least 1.25 times baseline over a 72-hour period after using contrast agent excluding other reasons.3.Statisical analysis: Data was analyzed using SPSS 21.0 software.Results were expressed as x—±s for quantitative variables and percentage for categorical variables.?2 test was used for comparison of categorical variables between groups.F test was used in the comparison of quantitative variables among multiple groups and the independent-samples t-test was used in the comparison of quantitative variables between two groups.The paired-samples t-test was used in the comparison of Scr,Ccr and eGFR within groups.P value less than 0.05 was accepted as the significance level.Results1.The comparison of general clinical data: There were no significant difference of baseline age,gender,height,weight,ejection fraction,Scr,Ccr,eGFR,complications,and CAG results among three groups(P>0.05),but the patients who took statins were much more than other two groups(P<0.05).2.The changes of renal function indexes: In control group and furosemide group,after operation Scr increased significantly(P<0.05),Ccr and GFR decrease significantly(P<0.05).While in furosemide combined with BNP group,there was no significant change of Scr,Ccr and eGFR after operation(P>0.05).Before operation,the differences of Scr,Ccr and eGFR among three groups did not have statistical significance(P>0.05).After operation,Scr in furosemide combined with BNP group was lower and GFR was higher than other two groups,which had statistical significance(P<0.05).All renal function indexes after operation in control group and furosemide group did not have statistical differences,neither did Ccr among three groups(P>0.05).3.The comparison of incidence rate of CIN: 0 patient in control group,54 patients in furosemide group,and 29 patients in furosemide combined with BNP group were received furosemide injection.As a result,the incidence rate of CIN among three groups had statistical differences(P=0.041).The incidence rate of CIN in furosemide combined with BNP group was obviously lower than another two groups,which had statistical significance(P<0.05).The incidence rate of CIN in control group an furosemide group did not have statistical difference(P>0.05).Conclusions1.Intravenous furosemide combined with hydration does not have extra clinical benefit compared with simple hydration.2.On the basis of adequate hydration,the effects of furosemide according to BNP levels on protecting renal function for patients with high risk are more obvious than that of directly using furosemide or simple hydration.3.Using furosemide according to BNP levels may reduce the incidence rate of CIN in high risk patients.