Correlation Between Serum Cystatin C And Heart Failure With Preserved Ejection Fraction In Elderly Patients

Objective:Heart failure(HF)is the leading cause of death in cardiovascular disease.Heart failure with preserved ejection fraction(HFpEF)accounts for about 50%of HF,and its prevalence and mortality are increasing year by year.The left ventricular ejection fraction of HFpEF is normal,and the signs and symptoms of HFpEF are usually not specific.The diagnosis of HFpEF has so far been challenging.Serum cystatin C(Cys-C)is an endogenous marker that reflects glomerular filtration rate.Recent studies suggest that its close correlation with ventricular remodeling and the producing constancy make it possible as an important indicator to diagnose and detect cardiovascular disease.This study was to detect the serum Cys-C level in elderly patients with HFpEF,and to analyze its correlation with cardiac function grading and echocardiographic parameters,in order to provide a clinical basis for the diagnosis of serum Cys-C in elderly patients with HFpEF.Method:95 patients with HFpEF who were admitted to the Department of Geriatrics of the Affiliated Hospital of Chengde Medical College from September 2017 to December 2018 were enrolled in the HFpEF group,which met the diagnostic criteria of HFpEF of the 2016 European Society of Cardiology(ESC),including 54 males and 41 females,aged 60-92 years.According to the New York Heart Association(NYHA)cardiac function classification,there were 55 cases of NYHA class?,31 cases of NYHA class?and 9 cases of NYHA class?.55 patients without heart failure admitted to the same period were included in the control group,including 31 males and 24females,aged 60-93 years.The basic clinical data such as gender,age,underlying disease,and cardiac function classification were recorded in detail.Serum Cys-C,N-terminal pro-brain natriuretic peptide(NT-proBNP),blood urea nitrogen(BUN),uric acid(UA),creatinine(Cr),echocardiography parameters including left ventricular ejection fraction(LVEF),left atrial diameter(LAD),Peak early diastolic mitral inflow velocity(E),Peak late diastolic mitral inflow velocity(A),Peak early diastolic mitral annular velocity(E?)were recorded for all subjects and statistical analysis was performed.Normally distributed measurement data were presented as the mea±standard deviation,and differences of means were compared between two groups using the t test and in multiple groups using the one-factor ANOVA.Non-normally distributed measurement data were presented as the median(interquartile range),and the Mann-Whitney U test was used for comparison between the two groups,and the Kruskal-Wallis H test was used for comparison between multiple groups.Categorical variables were expressed as percentages,and differences were analysed by the X~2 test.Correlation between the indicators was tested by Spearman rank correlation.The receiver operating characteristic curve(ROC curve)was used to determine the diagnostic value of serum Cys-C for elderly patients with heart failure and preserved ejection fraction,and the optimal cut-off value was determined by the Youden index.A P value<0.05 was considered statistically significant.Results:1.There were no significant differences in gender composition,incidence of hypertension and diabetes mellitus,blood glucose,blood urea nitrogen,uric acid and creatinine between the two groups(P>0.05).The age of patients in the HFpEF group[79(70,85)]was significantly older than in the control group[71(64,77)],(P<0.05).2.Serum Cys-C(1.09±0.30)mg/L and NT-proBNP[385.00(158.00,915.00)]pg/ml were higher in the HFpEF group than in the control group(0.93±0.20)mg/L,[65.00(50.00,109.73)]pg/ml,and the differences were statistically significant(P<0.05).There was no significant difference in serum Cys-C between NYHA class?and NYHA class?(P>0.05).Serum Cys-C in NYHA class?(1.37±0.34)mg/L was significantly higher than in NYHA class?(1.03±0.30)mg/L and NYHA class?(1.14±0.24)mg/L,(P<0.05).The results of serum NT-proBNP in different NYHA classifications were grade?[256.00(146.50,475.75)]pg/ml,grade?[598.00(218.00,1304.00)]pg/ml,grade?[2070.00(1473.00,3663.50)]pg/ml.With the increase of NYHA classification,the level of NT-proBNP increased gradually,and the differences were statistically significant between different groups(P<0.05).3.LAD was larger in the NYHA class?[35.00(31.00,39.00)]mm,NYHA class?[37.00(33.00,39.00)]mm,NYHA class?[40.00(35.00,42.50)]mm than the control group[32.00(29.00,34.25)]mm,meanwhile LAD in NYHA class?was larger than in NYHA class?and NYHA class?,the differences were statistically significant(P<0.05).But there was no significant difference in LAD between NYHA class?and NYHA class?(P>0.05).E?in NYHA class?[5.10(4.43,5.68)]cm/s,NYHA class?[4.00(3.80,4.90)]cm/s was lower than the control group[5.65(4.80,6.93)]cm/s,and NYHA class?[4.00(3.80,4.90)]cm/s was lower than NYHA class?[5.10(4.43,5.68)]cm/s,and the differences were statistically significant(P<0.05).There was no significant difference between NYHA class?,NYHA class?and the control group(P>0.05).E/E?was higher in NYHA class?(21.15±5.35)than in control group(13.88±4.12),NYHA class?(15.00±4.09),NYHA class?(15.37±4.11),and the difference was statistically significant(P<0.05),while there was no significant difference between the control group,NYHA class?and NYHA class?(P>0.05).There were no significant differences in LVEF,E,A and E/A between HFpEF group and the control group(P>0.05).4.The serum Cys-C levels was positively correlated with NT-proBNP,age,BUN,UA and Cr in the HFpEF group(r=331,0.524,0.341,0.205,0.375,P<0.05),while negatively correlated with E?,E/A(r=-0.200,-0.167,P<0.05),and not associated with blood glucose,LVEF,LAD,E,A and E/E?(P>0.05).5.The area under the ROC curve(AUC)for serum Cys-C,NT-proBNP,E/E?were 0.668[95%CI(0.583-0.754)],0.884[95%CI(0.822-0.946)],0.624[95%CI(0.531-0.717)],respectively.All had statistical significance(P<0.05).In this study,the optimal cut-off value for the diagnosis of HFpEF by serum Cys-C was 1.035 mg/L,the sensitivity was 56.8%,and the specificity was 76.4%.Conclusion:1.Serum Cys-C can be used as one of the new biomarkers for assessing the severity of HFpEF in elderly patients.2.Serum Cys-C has diagnostic value for HFpEF in the elderly.The best cut-off value for its diagnosis in this study is 1.035mg/L.Combined detection of NT-proBNP and echocardiography is helpful for the early diagnosis of HFpEF.