B-type natriuretic peptide levels in patients with functionally univentricular hearts after total cavopulmonary connection.

AIMS: To assess plasma B-type natriuretic peptide (BNP) levels in patients with univentricular hearts late after volume unloading by total cavopulmonary connection (TCPC). METHODS: Plasma BNP was measured by sandwich immunoassay in 67 patients after a modified Fontan procedure. BNP levels were compared with age and sex-specific normal values, clinical and echocardiographic data, and results of exercise testing. RESULTS: BNP had a wide range of 5-290 pg/ml, but was normal in 81% of patients, and median BNP was only 13 pg/ml. There was no difference between males and females, between patients with left or right ventricular morphology, and no correlation was found between BNP and age, post-operative follow-up period, maximum exercise capability, peak oxygen uptake, or blood oxygen saturation. New York Heart Association class I patients had lower BNP than class II patients (p=0.04). Plasma BNP concentration was positively correlated to the number of specific sequelae (r=0.59, p<0.001), and to severity of atrioventricular regurgitation (r=0.38, p=0.002). 5/13 patients with elevated BNP died during follow-up. CONCLUSION: BNP plasma concentration was normal in the majority of patients up to 15 years after TCPC. Elevated and increasing BNP levels were associated with increased morbidity and late mortality.

B-type natriuretic peptide in patients with systemic right ventricle.

OBJECTIVE: To examine the diagnostic value of B-type natriuretic peptide (BNP) in patients with systemic right ventricle. METHODS: Plasma BNP levels were measured in 48 outpatients with D-transposition of the great arteries after atrial switch procedure or congenitally corrected transposition of the great arteries. RESULTS: Plasma BNP was < or =20 pg/ml in 52% and <200 pg/ml in all patients, significantly higher in females compared to males (p = 0.004), and positively correlated with age (r = 0.3, p = 0.04). New York Heart Association class I patients had significantly lower BNP than class II patients (p = 0.03). A positive correlation was found between BNP and severity of tricuspid regurgitation (r = 0.5, p < 0.001). Plasma BNP was weakly, negatively correlated to maximum exercise capability, peak oxygen uptake, maximum heart rate during exercise testing and minimal heart rate in the 24-hour Holter monitoring. Additionally, BNP was negatively correlated with flow velocity across the pulmonary valve in patients with congenitally corrected transposition of the great arteries (r = -0.81, p = 0.03). CONCLUSION: Plasma BNP is normal in patients with systemic right ventricle, but increases with deterioration of clinical status and decreasing exercise capability. BNP is positively correlated with severity of tricuspid regurgitation, a prognostic factor for survival.

Plasma levels of B-type natriuretic peptide in patients with tetralogy of Fallot after surgical repair.

OBJECTIVE: To evaluate the utility of plasma BNP measurement in the long term follow-up of patients with surgically repaired tetralogy of Fallot (TOF). METHODS: From 2002 to 2008, plasma BNP concentration was measured in 130 patients with TOF at the age of mean 16.1+/-7.1 years and mean 13.0+/-6.5 years after surgically repair. BNP levels were compared to age and gender-specific normal values, results of exercise testing, clinical, electrocardiographic, and echocardiographic data. RESULTS: BNP was <200 pg/ml in all and elevated in 60% of patients. Higher values were found in females (p=0.001), in patients waiting for pulmonary valve replacement (p<0.001), and in NYHA class II compared to NYHA I patients (p=0.012) with an inverse correlation between BNP and exercise time (r=-0.59, p<0.001). BNP was correlated with right ventricular dilatation (r=0.29, p=0.005) and severity of both tricuspid (r=0.22, p=0.015) and pulmonary regurgitation (r=0.20, p=0.029). Longitudinal data revealed increasing BNP levels before (p=0.04) and a BNP decrease after pulmonary valve replacement (p=0.03), but no change in patients without surgery. CONCLUSIONS: In patients with surgically repaired TOF, plasma BNP is significantly correlated with right ventricular volume load. In clinical practice a considerable overlap limits the estimation of right ventricular volume load by BNP, but longitudinal evaluation helps to appoint the appropriate timing of pulmonary valve replacement.

Decreasing ratio of plasma N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide according to age.

BACKGROUND: B-type natriuretic peptide (BNP) and the N-terminal fragment of proBNP (NT-proBNP) seem to be useful diagnostic tools also in children with cardiac disease. Recent data suggest that plasma levels of both peptides show different patterns from infancy to adolescence. AIM: To investigate the relationship of BNP and NT-proBNP in children and adolescents according to age. SUBJECTS AND METHODS: In 46 individuals without cardiac disease (22 males, 24 females, aged 0.4-17.5 years) and 30 patients with congenital heart disease (17 males, 13 females, aged 0.2-18.4 years), plasma levels of BNP and NT-proBNP were measured in the same sample (triage BNP assay, Biosite and Elecsys NT-proBNP assay, Roche Diagnostics). RESULTS: The range of BNP plasma levels was 5-32 pg/ml in individuals without heart disease and 5-1300 pg/ml in the patient group, the range of NT-proBNP was 10-298 pg/ml and 30-18,966 pg/ml, respectively. In both groups, the ratio NT-proBNP/BNP decreased with increasing age (P<0.001). CONCLUSION: Although proBNP is cleaved into the two fragments NT-proBNP and BNP, there is a decreasing ratio of NT-proBNP/BNP with increasing age caused probably by age-dependent differences in the metabolic clearance of both peptides. This has to be considered in comparison studies on BNP and NT-proBNP regarding their benefit to paediatric cardiology.