The Role Of Plasma Amino-terminal Pro-B-type Natriuretic Peptide In The Diagnosis Of Heart Failure In Children

Objective: To explore the role of plasma amino-terminal pro-B-typenatriuretic peptide(NT-proBNP) in the diagnosis of heart failure(HF) in children,andto further investigate its cut-off value and diagnostic value after age stratification.Methods: From July2011to February2013,145children patients suspectedof HF were admitted to Affiliated Shunde Women and Children’s Hospital of JinanUniversity,including63children with HF(HF group) and82children patients withoutHF(no HF group) diagnosed according to the modified Ross score criteria and clinicalevidences.100healthy children were enrolled as control group.Dry-type quantitativeimmunofluorescence method was used to determine the level of plasma NT-proBNPin all children from this study.The differences in the level of plasma NT-proBNP werecompared among the above-mentioned three groups.The correlations were analyzedbetween NT-proBNP and other HF-related clinical indicators such as heartrate,respiratory rate,hepatomegaly,ejection fraction(EF), the modified Ross score.According to the modified Ross score,the Children with HF were divided into threesubgroups: mild,moderate and severe degrees,of which the differences in the level ofplasma NT-proBNP were compared.The diagnostic test for NT-proBNP diagnosingHF was evaluated in the children with HF according to the modified Ross criteria.The correlation between NT-proBNP and increasing age was analyzed in healthychildren to assess the influence that NT-proBNP was used to diagnose HF.Thechildren with HF were categorized into two subgroups:those3years of age or belowand those above3years of age,for whom the diagnostic tests were evaluated tocompare the changes of diagnostic value of NT-proBNP by age stratification.K-S testwas used to analyze if the level of plasma NT-proBNP was of normal distribution.The differences of NT-proBNP among groups were analyzed according to nonparametrictest.Pearson correlation was used for correlation analysis.ROC(receiver opertorcharacteristic)curve and fourfold table were used to evaluate the diagnostic tests.Datewas analyzed by SPSS13.0.Results:1.The level of plasma NT-proBNP from the subject is not of normaldistribution(P all＜0.05).2.There was significant difference in the level of plasmaNT-proBNP among HF group,no HF group and control group(χ~2=140.053,P=0.000).The level of plasma NT-proBNP in HF group was higher than that of no HFgroup and control group(Z=-10.275，-10.725， P all=0.000).And there was nosignificant difference between no HF group and control group(Z=-1.120，P＞0.05).3.In children with HF,the level of plasma NT-proBNP and heart rate,respiratoryrate,hepatomegaly, the modified Ross score were positively correlated(r=0.743,0.710,0.686,0.867, P all=0.000), while that and EF was negatively correlated(r=-0.760，P=0.000).4.There was significant difference in the level of plasma NT-proBNP indifferent degrees of HF(χ~2=44.272，P=0.000). The level of plasma NT-proBNP insevere HF group was higher than that of moderate HF group(Z=-4.164，P=0.000),and itwas also higher in moderate HF group than that of mild HF group(Z=-5.121，P=0.000).5.The area under the ROC curve(AUC) for NT-proBNP diagnosing HF was0.932inHF group.The optimal cut-off value,sensitivity,specificity and Youden index were495ng/L,82.5%,84.1%and0.666.6.The level of plasma NT-proBNP and increasingage was negatively correlated in healthy children(r=-0.739，P=0.000).There wassignificant difference between the patients with HF below3years of age and thoseabove3years of age in the level of plasma NT-proBNP(Z=-2.448，P＜0.05).7.Afterage stratification,the AUC for NT-proBNP diagnosing HF rose to0.943in the patientsbelow3years of age and0.956in those above3years of age,and Youden indexcorrespondingly rose to0.785and0.783. The optimal cut-off values were respectively596ng/L and332.5ng/L.Conclusions:1.The level of plasma NT-proBNP in children with HF is significantly higher than that of children patients without HF and healthy children.Inchildren with HF, the level of plasma NT-proBNP and HF-related clinicalindicators(increasing heart rate,tachypnea and hepatomegaly),EF,the modified Rossscore are significantly correlated.The level of plasma NT-proBNP can reflect theseverity of HF in children,which is useful for diagnosing HF in children.2.It may beinfluenced by age factor that NT-proBNP diagnoses HF in children,and the cut-offvalue in children below3years of age is higher than that of children above3years ofage.3.After age stratification,the value for diagnosing HF in children is furtherimproved.