Effect Of Abnormal Renal Function On Diagnosis And Treatment Of Chronic Heart Failure With NT-proBNP

BackgroundsHeart failure means that the heart can not pump enough blood to meet all the needs of the body.The reason for its occurrence can be the systolic or diastolic dysfunction caused by myocardial injury,cardiac valve dysfunction and arrhythmia.Heart failure often have typical clinical symptoms and signs such as dyspnea,fatigue,Lower limbs edema;jugular venous,diffuse bilateral pulmonary rales,apical pulse position changes.Because the clinical symptoms and signs of heart failure are often not specific,the diagnosis of heart failure still needs some auxiliary examinations,such as chest radiography and echocardiography.However,these auxiliary inspections are expensive and subjective.Therefore,it is necessary to further look for objective,convenient and fast monitoring indicators.In 2001 the European Society of Cardiology for the first time put forward the use of serum BNP to assist in the diagnosis of chronic heart failure,afterwards a large number of studies also validated the value of BNP/NT-proBNP in the diagnosis of heart failure.The concentrations of serum BNP/NT-proBNP have been used clinically as a general indicator of screening and disease surveillance.BNP/NT-proBNP is produced by the cleavage of proBNP,and when cardiomyocytes are pulled by external force,a large number of ventricular myocytes synthesize and secrete proBNP.During this process,proBNP is decomposed into bioactive BNP And no bioactive NT-proBNP.Compared with BNP,NT-proBNP has a longer biological half-life in the human body(1 to 2h,BNP is about 20min),and the plasma concentration is relatively higher(about 15~20 times of BNP),so it become a Sensitive and specific marker for the diagnosis of congestive heart failure.However,As NT-proBNP mainly has renal clearance and is susceptible to renal function in patients.Therefore,the clinical value of NT-proBNP in the diagnosis of heart failure was questioned in patients with renal insufficiency.ObjectiveThe patients with heart failure were staging according to renal function to study the effect of renal dysfunction on plasma NT-proBNP concentration in patients with chronic heart failure,and further to get the cutoff values of serum NT-proBNP in patients with different renal function stages.MethodsA total of 303 patients with chronic heart failure admitted to the First Affiliated Hospital of Zhengzhou University from January 2016 to September 2017 were selected.Chronic heart failure is diagnosed according to the guidelines for diagnosis and treatment of heart failure in China in 2014.It requires a clear heart disease in the diagnosis of heart failure and satisfies the following three conditions:1.Clinical symptoms:chest tightness,dizziness,wheezing,and weakness,orthopnoea,etc.2.Signs:accelerated heart rate,edema of the lower limbs,wet rales of the lungs,galloping,etc.3.Auxiliary examinations:chest X-ray shows enlargement of the heart shadow or congestion of the lungs,Echocardiography shows abnormal of diastolic function or systolic function of the heart,increased serum NT-proBNP levels,etc.According to the 2002 American Society of Nephrology"chronic kidney disease clinical practice guidelines"provisions,The patients were divided into normal renal function group(eGFR?90ml/min/1.73 m~2,n=78)and mild renal insufficiency group(90ml/min/1.73 m~2>eGFR?60ml/min/1.73 m~2,n=72),moderate renal dysfunction group(60ng/min/1.73m~2>eGFR?30ml/min/1.73m~2,n=77)and severe renal dysfunction group(eGFR<30ml/min/1.73m~2).Patients admitted to the hospital were collected age,gender,medical history,heart rate,blood pressure,ECG and other general clinical datas.Serum creatinine,eGFR,troponin and NT-proBNP were also measured after admission.Left ventricular ejection fraction(LVEF)and left ventricular end-diastolic diameter(LVDd)were recorded by echocardiography.SPSS 21.0 statistical software is used for statistical processing of data.Measured data with normal distribution are expressed as?x±s,Measurement data that do not meet the normal distribution are represented by the median(M)and the interquartile range(P75-P25),and the comparison of multiple sets of data is performed using a single factor variance analysis,The two sets of data are compared using t test between two independent samples;Comparisons of non-normally distributed sets of data use rank sum tests,?~2 test is used to compare the categorical variables;Spearman correlation analysis is used to analyze the correlation;ROC curves are plotted for the test results and the area under the ROC curve(AUC)for each group is analyzed to determine the NT-proBNP cutoff values for different renal function groups.P<0.05,the difference is statistically significant,while P<0.01,the difference is more statistically significant.Results1.The differences of eGFR between different renal function groups arestatistically significant(P<0.01).There are no significant differences in sex,age,and left ventricular ejection fraction.(P>0.05).2.Spearman correlation analysis showes that there is a significant negative correlation between NT-proBNP and eGFR in patients with chronic heart failure(r=-0.650,p<0.01).3.Spearman correlation analysis showes that there is aslo a negative correlation between NT-proBNP and LVEF in patients with chronic heart failure(r=-0.126,P<0.05).4.The comparisons of NT-proBNP levels among the groups with normal renal function,mild,moderate and severe renal dysfunction show significant differences(P<0.01).5.With mild renal insufficiency(90 ml/min/1.73 m~2>eGFR?60 ml/min/1.73 m~2),NT-proBNP has the best cut-off value for the diagnosis of heart failure of 3201pg/ml,with a sensitivity of 63%and a specificity of 65%,the area under the ROC curve(AUC)is 0.678(95%CI:0.593 to 0.763,P<0.001);As to moderate renal insufficiency(60 ml/min/1.73 m~2>eGFR?30 ml/min/1.73 m~2),The best cut-off value of NT-proBNP in the diagnosis of heart failure is 7397 pg/ml,the sensitivity is 65%,while the specificity is 76%,and the area under the curve(AUC)is 0.756(95%CI:0.677 to 0.834,P<0.001).For severe renal insufficiency(eGFR<30 ml/min/1.73 m~2),NT-proBNP having the best cut-off for heart failure is 11310pg/ml,sensitivity is68%,specificity is 87%,The area under the curve(AUC)is 0.742(95%CI:0.659 to0.826,P<0.001).Conclusions1.When patients with heart failure have renal dysfunction,serum NT-proBNP levels increase significantly and are positively correlated with renal insufficiency.2.when we use NT-proBNP to diagnose heart failure,the renal function status of the patients should be taken into account;for different renal function states,the cut off values of NT-proBNP in the diagnosis of heart failure will be different.