The value of serum N-terminal pro-brain natriuretic peptide levels in the differential diagnosis and follow-up of congestive cardiac failure and respiratory distress due to pulmonary aetiologies in infants and children

Serum Biomarkers for the Detection of Cardiac Dysfunction in Childhood Cancers Receiving Anthracycline-Based Treatment

Anthracyclines are routinely used in cancer chemotherapy in many childhood cancers. A serious adverse effect of doxorubicin chemotherapy is cardiotoxicity which may lead to congestive heart failure for long-term survivors years after treatment. Currently, echocardiography is used to control the heart function during anthracyclines therapy. B-type natriuretic peptide (BNP) and NT-proBNP as well as cardiac troponins have been proposed as clinical markers for subclinical anthracycline-induced cardiotoxicity. The BNP and pro-BNP can be easily measured in plasma and initial data indicate that the NT-proBNP could be sensitive predictor for the development of congestive heart failure.

Mitral Regurgitation and Serum N-Terminal Pro-Brain Natriuretic Peptide Levels in Children: A Modification of Adult Criteria

Mitral regurgitation can result from congenital heart disease, rheumatic valve disease, or other congenital malformations of the mitral valve. Faulty valves require surgical repair or replacement. However, echocardiographic and biochemical parameters that inform surgical decision-making for adults may not be appropriate for children. To investigate whether adult parameters can be used in children, we correlated echocardiographic parameters with serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in children with chronic mitral regurgitation. Our sample comprised 45 patients and 38 healthy children. M-mode measurements, left atrial and left ventricular volumes, and Doppler and tissue Doppler echocardiograms were collected. We graded mitral regurgitation according to European Association of Echocardiography recommendations and indexed effective regurgitant area, vena contracta, and regurgitant volume to body surface area. Patients were grouped by regurgitation severity (mild vs moderate or severe) and left ventricular end-systolic dimension (normal vs enlarged). The NT-proBNP level was higher in patients than in controls (P=0.003), higher in patients with moderate or severe regurgitation (P=0.02), and higher in patients with an enlarged left ventricle (P=0.003). Serum NT-proBNP levels correlated with effective regurgitant area (r=0.47; P=0.002), vena contracta width (r=0.46; P=0.003), regurgitant volume (r=0.32; P=0.04), left ventricular end-systolic diameter (r=0.58; P <0.001), and left atrial diameter (r=0.62; P <0.001). An NT-proBNP value of 66 pg/mL differentiated the mild regurgitation group from the moderate or severe regurgitation group. Our results correlating NT-proBNP and echocardiographic parameters indexed to body surface area indicate that these adult criteria can be used in children to grade mitral regurgitation and inform surgical decision-making.

How to use N-terminal pro-brain natriuretic peptide (NT-proBNP) in assessing disease severity in bronchiolitis

Bronchiolitis is a common viral illness which can lead to severe respiratory compromise and can coexist with or mask cardiac failure. Brain natriuretic peptide (BNP) and the inactive portion of its pro-hormone: N-terminal pro-BNP (NT-proBNP) are excreted in response to cardiomyocyte stretching and are established biomarkers in cardiac failure. Here, we discuss the technicalities of NT-proBNP testing and review available evidence regarding NT-proBNP testing in bronchiolitis. We identified and appraised seven studies assessing the role of BNP or NT-proBNP as biomarkers of bronchiolitis severity, in children with and without underlying congenital cardiac disease. One study of 76 children with dyspnoea showed that the median NT-proBNP level in children with cardiac failure was 7321 pg/mL vs 241 pg/mL in children with a respiratory cause of dyspnoea vs 87.21 pg/mL in healthy controls (p<0.05). A cut-off of 726 pg/mL could aid differentiation between cardiac and respiratory causes of respiratory distress. Other evidence showed a positive correlation between BNP levels and bronchiolitis severity, and that raised BNP can predict acute heart failure in children with congenital cardiac disease presenting with bronchiolitis. However, most studies consisted of small cohorts with conflicting evidence between them. Furthermore, several studies assessed BNP rather than NT-proBNP directly. BNP has a shorter half-life, which may affect analysis. In conclusion, NT-proBNP is a rapid and inexpensive test with the potential to be a useful biomarker in severe bronchiolitis and cases complicated by acute cardiac failure. However, studies with larger cohorts are required to better establish this role.

Alterations in cerebral blood flow in children with congestive heart failure due to ventricular septal defect

OBJECTIVE

We aimed to investigate the effect of ventricular septal defect (VSD) and heart failure on cerebral blood flow (CBF) in children, whether heart failure treatment improves CBF, and if there is any relationship between CBF and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) level.

METHOD

Forty children with VSD (13 with heart failure) aged between 1 and 36 months were studied. The control group comprised 25 healthy children in the same age group. Maximum, minimum, and mean blood flow velocities and pulsatility indices of the right and left middle cerebral arteries were assessed using transcranial Doppler ultrasonography. Measurements of CBF and serum NT-proBNP levels were repeated in patients with heart failure a month post-heart failure treatment initiation. The groups were also compared in terms of defect diameters, cardiac structural changes, left ventricular systolic function, and findings related to pulmonary hypertension determined by echocardiography. Correlations between echocardiographic measurements and CBF parameters were analyzed.

RESULTS

Although no significant difference was found between patient and control groups for CBF, right and left maximum CBF velocities significantly increased posttreatment in patients with heart failure (P = .04 and P = .01, respectively). Serum NT-proBNP levels in children with VSD associated with heart failure were significantly higher than those in children with VSD alone (P = .04) or in healthy children (P < .001). NT-proBNP levels were negatively correlated with right and left maximum CBF velocities (r = -0.39, P = .013 and r = -0.32, P = .043, respectively).

CONCLUSION

Although no significant difference was found in CBF velocity among the study groups, increase in the CBF velocity post heart failure treatment and negative correlations between CBF velocity and both the VSD diameter and NT-proBNP levels indicate that the hemodynamic status due to VSD associated with heart failure has an effect on CBF.

N-terminal pro-brain natriuretic peptide in the assessment of respiratory distress in term neonates

BACKGROUND

N-terminal pro-brain natriuretic peptide (NT-proBNP) is used as a biomarker to differentiate congestive heart failure from lung disease in adults and children. The clinical significance of its use in term neonates has not yet been extensively studied.

METHODS

NT-proBNP level was measured in 62 term neonates admitted for respiratory distress (RD): 38 with congenital heart disease (CHD) and 24 with pulmonary disease. The control group consisted of 28 healthy neonates. Findings of auscultation, chest radiography, Silverman-Anderson score and echocardiography were recorded for each patient. Blood samples for measuring NT-proBNP were collected on admission, when blood sampling was indicated for the clinical management of the newborn.

RESULTS

In the control group NT-proBNP was significantly higher during the first week of life compared to the rest of the neonatal period (P < 0.001). The RD group, regardless of etiology, had significantly higher NT-proBNP than the control group (P < 0.001). Neonates with more severe RD had significantly higher NT-proBNP (P = 0.002). No significant difference was found between the RD group with CHD and those with pulmonary disease. Neonates with CHD and myocardial hypocontractility had significantly higher NT-proBNP than those with normal contractility (P = 0.022).

CONCLUSION

Term neonates with RD have significantly higher NT-proBNP than healthy neonates. A single measurement of NT-proBNP level cannot be used as the sole biomarker for distinguishing between cardiac and pulmonary cause of RD in term neonates.

The Ross classification for heart failure in children after 25 years: a review and an age-stratified revision

Accurate grading of the presence and severity of heart failure (HF) signs and symptoms in infants and children remains challenging. It has been 25 years since the Ross classification was first used for this purpose. Since then, several modifications of the system have been used and others proposed. New evidence has shown that in addition to signs and symptoms, data from echocardiography, exercise testing, and biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP) all are useful in stratifying outcomes for children with HF. It also is apparent that grading of signs and symptoms in children is dependent on age because infants manifest HF differently than toddlers and older children. This review culminates in a proposed new age-based Ross classification for HF in children that incorporates the most useful data from the last two decades. Testing of this new system will be important to determine whether an age-stratified scoring system can unify the way communication of HF severity and research on HF in children is performed in the future.

Natriuretic peptides in children: physiology and clinical utility

PURPOSE OF REVIEW

This article reviews the genetics, biochemistry, and physiology of the natriuretic polypeptide family and their receptors; their roles in cardiac, bone, and lipid metabolism in children; and pharmacological agents that utilize the natriuretic polypeptide system.

RECENT FINDINGS

Clinically, measurements of circulating levels of the natriuretic polypeptides are useful diagnostic and prognostic markers of cardiovascular disease in children. The natriuretic polypeptides also play an important role in growth and body composition. Therapeutic application of the natriuretic polypeptide system may provide new treatments for cardiac, renal, bone, and metabolic disease in children.

SUMMARY

The natriuretic polypeptide system has promising clinical utility in the care of pediatric patients with cardiac, renal, bone, and metabolic disease.