Atrial natriuretic peptide concentrations in children with pulmonary hypertension: correlation with hemodynamic measurements

Biological serum markers in the management of pediatric pulmonary arterial hypertension

Appropriate parameters are needed for the monitoring of children with pulmonary arterial hypertension (PAH). Various biologic markers seem to be of use in adults with PAH. No data are available on their value in children with PAH. In this study, the relation between serum markers, functional parameters, and hemodynamic variables in pediatric PAH and their ability to predict survival is determined. Serum N-terminal pro brain natriuretic peptide (NT-proBNP), uric acid, norepinephrine, and epinephrine were measured and correlated with invasive hemodynamics, functional parameters, and outcome in 29 pediatric patients with PAH who visited a tertiary reference center for pediatric PAH between 1997 and 2005. NT-proBNP correlated with functional class (R = 0.36; p = 0.03) and 6-min walking distance (6MWD) (R = -0.53; p < 0.001). Uric acid correlated with mean pulmonary arterial pressure, pulmonary vascular resistance, and cardiac index (R = 0.63, p = 0.01; R = 0.71, p = 0.03, and R = -0.65, p = 0.007, respectively). After initiation of treatment, NT-proBNP decreased. This decrease correlated with an increased 6MWD. Finally, norepinephrine and NT-proBNP levels were highly predictive for mortality. In this series of children with PAH, biologic markers were correlated with hemodynamics and functional capacity, as parameters of disease severity. The data indicate that these markers can be used to monitor treatment effects and predict mortality in pediatric PAH.

Clinical value of NT-ProBNP and BNP in pediatric cardiology

BACKGROUND

Although less common than in adults, heart disease is a significant cause for morbidity and death in infants and children. Congenital structural cardiac anomalies and acquired heart diseases may result in heart failure.

METHODS AND RESULTS

Available data suggest that the natriuretic peptide system has a similar role in health and disease in the pediatric age group as in adults. In healthy infants and children, levels of B-type natriuretic peptide (BNP) and the N-terminal segment of its pro-hormone (NT-proBNP) are elevated in the first few days after birth. Thereafter, their levels decrease and remain relatively constant throughout childhood. Infants and children with heart disease that causes significant pressure or volume overload of the right or the left ventricle have elevated BNP and NT-proBNP levels. In children with congestive heart failure, BNP and NT-proBNP levels correlate with functional capacity. Both peptides can differentiate cardiac from pulmonary causes in infants with respiratory distress. Limited data suggest that these peptides may also serve as markers in cyanotic, obstructive, and inflammatory heart diseases.

CONCLUSION

The present data suggest that both NT-proBNP and BNP are markers for heart disease in infants and children. Their use may improve clinical practice in pediatric cardiology.

Plasma atrial natriuretic peptide in fetuses with cardiac disease

OBJECTIVE

To investigate atrial natriuretic peptide (ANP) levels in fetuses with cardiac defects and to evaluate the relationships between plasma ANP levels and the presence of polyhydramnios.

METHODS

Plasma ANP levels were measured by radioimmunoassay in 27 fetuses with cardiac abnormalities and in 14 normal healthy fetuses.

RESULTS

Fetal plasma ANP levels were similar in the two studied groups (p = 0.18) but they were significantly higher in a subset of cases with cardiac disease and polyhydramnios (n = 7) than in those with cardiac disease and normal amniotic fluid (n = 20; p = 0.036) and controls (p = 0.01).

CONCLUSION

Polyhydramnios in fetuses with heart conditions might be explained by increased fetal diuresis secondary to increased ANP production.

Clinical implication of plasma natriuretic peptides in children with ventricular septal defect

BACKGROUND

There is little information available concerning plasma concentrations of B-type natriuretic peptide (BNP) in children with a ventricular septal defect. The aim of the present study was to determine hemodynamic factors that control plasma concentrations of BNP and the clinical implications of BNP compared with atrial natriuretic peptide (ANP) in children with ventricular septal defect.

METHODS

Fifty-nine patients with ventricular septal defect (28 boys and 31 girls) without pulmonary vascular disease were enrolled. The patients' ages ranged from 3 months to 13 years (mean 3.1 years). Plasma BNP and ANP were determined by immunoradiometric assay. Hemodynamic variables derived from cardiac catheterization were analyzed in terms of correlation with BNP and ANP.

RESULTS

It was found that plasma BNP significantly positively correlated with ANP (ANP = 2.1 x BNP + 25 pg/mL; r = 0.81, P < 0.0001) and BNP never exceeded ANP in the present patient series. Plasma BNP as well as ANP significantly positively correlated with pulmonary to systemic flow ratio (r = 0.65 and r = 0.59, respectively) and mean pulmonary artery pressure (r = 0.72 and r = 0.68, respectively). In addition, plasma BNP of > or =20 pg/mL and ANP of > or =50 pg/mL identified children with mean pulmonary artery pressure of > or =20 mmHg with a sensitivity of 82% and 97%, respectively, and a specificity of 89% and 84%, respectively.

CONCLUSION

Plasma BNP and ANP reflect pressure and volume loads to the pulmonary artery and right ventricle and may help to identify children with ventricular septal defect complicated by pulmonary hypertension that demands early intervention.

Elevation of atrial natriuretic peptide prohormone. Hemodynamic background of the elevation of N-terminal natriuretic peptide prohormone in children with congenital heart disease

We postulated previously that variables related to pulmonary flow are independent predictors of levels of atrial natriuretic peptide in children with congenital heart disease. The aim of this study was to test this hypothesis in relation to other hemodynamic and clinical variables. During catheterization we measured the levels of plasma N-terminal atrial natriuretic peptide prohormone in the plasma of 68 children with congenital heart disease. All had undergone complete clinical, echocardiographic and invasive hemodynamic investigations. The influence on the prohormone was analyzed for 10 different variables in a multiple linear regression model. The variability could be explained in large parts (adjusted R2 =77.2%) by variations in atrial pressures or sizes, together with the degree of excessive pulmonary blood flow and signs of heart failure. A value for atrial natriuretic peptide prohormone above 800 pmol/l predicted hemodynamic imbalance (defined as elevated pressures in left or right atrium or the pulmonary arteries, and/or Qp/Qs > 1.5) with a specificity of 94%, a sensitivity of 73%, a positive likelihood ratio of 12.2, and a negative likelihood ratio of 0.29. In conclusion, variables related to pulmonary blood flow are influential determinants of the levels of atrial natriureic peptide in children with congenital heart disease. Atrial pressures, and symptoms of heart failure are also of major importance.

Interventional catheterization decreases plasma levels of atrial natriuretic peptide (ANP) in children with congenital heart defects

Atrial natriuretic peptide (ANP) is one of the cardiac peptides implicated in volume and sodium homeostasis. We investigated the effect of interventional catheterization on plasma levels of ANP, aldosterone, and cortisol in 28 children with various congenital heart defects (CHD). Patients were divided by age into two groups: group A--infants and children over 3 months of age (n = 22), and group B--newborns (n = 6). These were compared to age-matched control groups. In group A, interventions included pulmonic valvotomy (n = 8), aortic valvotomy (n = 4), balloon angioplasty of native coarctation of the aorta (n = 3), balloon dilatation of the mitral valve (n = 1), and Rashkind double umbrella closure of patent ductus arteriosus (n = 6). Group B interventions included pulmonic valvotomy (n = 3), aortic valvotomy (n = 1), and balloon atrial septosomy (n = 2). In group A, mean ANP levels were markedly higher than in age-matched controls (125.2+/-15.8 vs. 24.6+/-4.6 pg/ml) (P <0.0001), and decreased immediately after intervention (75.6+/-11.4 pg/ml, P <0.02), and more markedly on follow-up (42.9+/-5.0 pg/ml, P < 0.0001). In group B (newborns), mean basal plasma levels were high before and after intervention and were not different from age-matched controls (243+/-42.1 vs. 220.8+/-16.2 pg/ml). There was a significant decrease on follow-up measurement (62.1+/-12.7 pg/ml, P < 0.005). In both groups, plasma cortisol levels increased significantly immediately following catheterization (P < 0.02), and normalized on follow-up. Basal aldosterone levels were normal in group A and high in Group B (9.9+/-3.8 vs. 167.6+/-16.9 ng/dl) (P < 0.001). It is suggested that plasma ANP levels are increased in children with CHD, without overt heart failure, and decrease significantly following successful intervention. In newborns with CHD, the physiological high ANP levels obscure the effect of the CHD.

Correlation of Atrial Natriuretic Factor and Renin-Aldosterone System With Chronic Pulmonary Hypertension Among Residents in a High Altitude

The study was performed to evaluate right ventricular contractility, plasma renin activity, and atrial natriuretic peptide in high altitude pulmonary arterial hypertension (HAPH). Sixty-eight patients with signs of pulmonary artery hypertension (PPA,syst > 25 mmHg, PPA > 15 mmHg) (Group II) and 40 with normal coronary angiograms and normal pulmonary artery pressures (Group I) were included in the study. Right heart catheterization with estimation of right ventricular and pulmonary artery pressures were performed in all the patients. The blood samples were taken from the pulmonary artery for measurement of mean oxygen saturatioýn (SaO2), atrial natriuretic factor (ANF) level, plasma renin activity (PRA), aldosterone level, and sodium and potassium concentrations. Statistical analysis was performed using unpaired Student's t test and linear regression analysis. The patients with HAPH had higher pulmonary artery pressures (PPA,syst, PPA, PPA,diast), total pulmonary resistance (Rpulm,tot), and right ventricular systolic pressure (PRv,syst). The significant correlation was found between ANF and PRA with right ventricular contractility indices and pulmonary vascular resistance.