[Diagnostic value of plasma concentration of pro-brain natriuretic peptide in congestive heart failure in pediatric patients with ventricular septal defects].

OBJECTIVE: The value of plasma brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) can reflect cardiac function and therefore can be used for diagnosing congestive heart failure (CHF) and evaluating cardiac function. There are few reports, however, on the value of BNP and NT-proBNP in pediatric cases of congenital heart defect. The aim of this study was to assess the value of plasma NT-proBNP in the diagnosis of CHF and evaluation of cardiac function in pediatric patients with ventricular septal defect (VSD).

METHODS: Fifty-one patients with VSD aged from 2 months to 2 years old (mean 7.9 months) were enrolled. According to the modified Ross Score, the patients were divided into three groups, no CHF group (20 patients), mild CHF group (18 patients) and moderate to severe CHF group (13 patients). Fifteen age-matched normal children were used as controls. Plasma NT-proBNP was measured using enzyme immunoassay. All patients had complete echocardiographic study, including measurement of left ventricular end diastolic volume index (LVEDVI), left ventricular end systolic wall stress (LVSEWS), heart rate corrected mean velocity of circumferential fiber shortening (mVcFc), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and contractility index (Con). The correlation between plasma NT-proBNP level and modified Ross Score and echocardiographic cardiac functional indexes was determined. The sensitivity, specificity and ROC curve of plasma NT-proBNP for diagnosing CHF was studied.

RESULTS: Plasma NT-proBNP was positively correlated with modified Ross Score (r = 0.75, P < 0.01). Plasma NT-proBNP concentration in moderate to severe CHF group (2061 +/- 908) fmol/ml was significantly higher than that of mild CHF group (810 +/- 335) fmol/ml, and Plasma NT-proBNP concentration in mild CHF group was higher than that in no CHF group (309 +/- 68) fmol/ml. 97.14% of normal controls and subjects in no CHF group had their plasma NT-proBNP below 400 fmol/ml. 83.3% of children in mild CHF group had their plasma NT-proBNP between (400-1400) fmol/ml while in moderate and severe CHF group 84.6% of children had their plasma NT-proBNP beyond 1400 fmol/ml. Plasma NT-proBNP was also positively correlated with LVEDVI and LVSEWS. There was no correlation among mVcFc, LVEF, LVFS, Con and plasma NT-proBNP concentration. Using plasma NT-proBNP concentration > or = 400 fmol/ml as cut-point for diagnosing CHF, the sensitivity was 89.3%, the specificity was 91.2%, and the area under the ROC curve was 0.944.

CONCLUSIONS: Plasma NT-proBNP level could be used to assess cardiac function and diagnose CHF in pediatric patients with VSD.