The use of B-type natriuretic peptide in paediatric patients: a review of literature

Evaluation of the impact of treatment with hematopoietic stem cells transplantation (HSCT) on biochemical markers of heart function and novel electrocardiographic markers of repolarization in patients with hematological malignancies

High-dose chemotherapy (HDC) followed by stem cell transplantation (HSCT) is a well-established method in patients with hematological malignancies, and for last few years, many efforts have been made to estimate short- and long-term efficacy of this method, as well as early and late complications. The present study concentrates on cardiotoxic effects, mainly early changes using biochemical markers such as N-terminal natriuretic peptide type B (NT-proBNP) and cardiac troponins (cTn). Simultaneously, the analysis of 12-lead ECG was done before and after the procedure in which the novel repolarization markers: T_p-e and T_p-e/QT ratio were measured, together with standard markers: QT, QTc. It was found that NT-pro BNP was significantly increased after HSCT in comparison to results before it, and no significant changes were present in Troponin levels. Simultaneously, T_p-e interval and T_p-e/QT ratio were significantly higher after HSCT. The use of cyclophosphamide, advanced age, and higher level of blood cholesterol concentration were risk factors for the increase in NT-proBNP and treatment with cyclophosphamide as well as fludarabine and higher creatinine levels were risk factors for the increase in T_p-e/QT ratio. In conclusion, in the early term evaluation after HSCT in patients with no previously diagnosed heart disease, the mild changes in markers of heart overload and repolarization were noted. The observations suggest that in all patients undergoing HSCT, even the ones without pre-existing cardiovascular disease, the evaluation, and monitoring of heart function should be considered.

Design for the sacubitril/valsartan (LCZ696) compared with enalapril study of pediatric patients with heart failure due to systemic left ventricle systolic dysfunction (PANORAMA-HF study)

BACKGROUND

Sacubitril/valsartan (LCZ696) is an angiotensin receptor neprilysin inhibitor approved for the treatment of adult heart failure (HF); however, the benefit of sacubitril/valsartan in pediatric HF patients is unknown.

STUDY DESIGN

This global multi-center study will use an adaptive, seamless two-part design. Part 1 will assess the pharmacokinetics/pharmacodynamics of single ascending doses of sacubitril/valsartan in pediatric (1 month to <18 years) HF patients with systemic left ventricle and reduced left ventricular systolic function stratified into 3 age groups (Group 1: 6 to <18 years; Group 2: 1 to <6 years; Group 3: 1 month to <1 year). Part 2 is a 52-week, efficacy and safety study where 360 eligible patients will be randomized to sacubitril/valsartan or enalapril. A novel global rank primary endpoint derived by ranking patients (worst-to-best outcome) based on clinical events such as death, initiation of mechanical life support, listing for urgent heart transplant, worsening HF, measures of functional capacity (NYHA/Ross scores), and patient-reported HF symptoms will be used to assess efficacy.

CONCLUSION

The PANORAMA-HF study, which will be the largest prospective pediatric HF trial conducted to date and the first to use a global rank primary endpoint, will determine whether sacubitril/valsartan is superior to enalapril for treatment of pediatric HF patients with reduced systemic left ventricular systolic function.

What Is High Enough? Elevated NT-pro-BNP in Decompensated Paroxysmal Supraventricular Tachycardia

Since the late 1980s, elevated atrial natriuretic peptide (ANP) was considered the cause of brisk diuresis in adult patients with paroxysmal supraventricular tachycardia (PSVT). Pro-brain natriuretic peptide (pro-BNP) and related molecules, e.g., N-terminal pro b-type natriuretic peptide (NT-pro-BNP) are known biomarkers of heart failure in adult patients from many causes with probable relevance in children. Perhaps, pro-BNP or related molecules such as NT-pro-BNP are useful in the management of PSVT in infants, thus hastening treatment in children who may otherwise significantly decompensate. Case series of one infant and two neonates presenting with cardiogenic shock and evidence of heart failure are presented. Cardiac monitoring or electrocardiogram (ECG) confirmed the presence of PSVT. Adenosine was administered resulting in successful chemical cardioversion with each case. Significantly elevated NT-pro-BNP levels correlated with heart failure prior to cardioversion. In each case, patients were discharged home with lower NT-pro-BNP levels and maintenance with a β-blocker. Due to documented relationships between elevated pro-BNP level and heart failure in adults, the authors measured the related biomarker NT-pro-BNP in each case, as the relationship could be similar in pediatric PSVT. Based on our experience with children in acute heart failure from other causes, NT-pro-BNP can increase to potentially extreme levels in infants. It appears to correlate with clinical signs of insufficient cardiac output, such as tachycardia, respiratory distress, and moribund appearance. Indeed, in the case series, extremely high NT-pro-BNP values were obtained when the patients appeared moribund from decompensated PSVT. The question arising from these observations is: At what level of elevated NT-pro-BNP, would patients be identified for cardioversion prior to appearance of other signs and symptoms? For each patient within the case series, NT-pro-BNP levels of approximately 20,000 pg/mL were indicative of decompensated heart failure, which was subsequently confirmed by examination of the patient. Further investigation is needed to determine the clinical significance of NT-pro-BNP and related peptides in pediatric patients with PSVT and intermittent PSVT. However, the possibility exists that an increase in NT-pro-BNP and related peptides could be a biomarker for cardiac decompensation after prolonged or intermittent PSVT, thereby shortening the time of diagnosis and intervention, and hence, potentially preventing morbidity, mortality, and extended hospitalization. Additional evidence-based research would help provide biomarker information during PSVT allowing practitioners to more objectively analyze risks.

Effect of Carvedilol on Serum Heart-type Fatty Acid-binding Protein, Brain Natriuretic Peptide, and Cardiac Function in Patients With Chronic Heart Failure

OBJECTIVE

To observe the changes of serum heart-type fatty acid-binding protein (h-FABP) and brain natriuretic peptide (BNP) in children with chronic heart failure (CHF) and evaluate the effects of carvedilol.

METHODS

A total of 36 patients with CHF, including 17 of endocardial fibroelastosis and 19 of dilated cardiomyopathy, were enrolled and were randomly divided into a carvedilol treatment group (group A) and a conventional treatment group (group B). Group A (n = 16) was treated with carvedilol and conventional treatment and group B (n = 20) was managed with conventional treatment only. Thirty healthy children were enrolled as controls. The concentrations of serum h-FABP and BNP were measured by enzyme-linked immunosorbent assay, and the left ventricular end-systolic diameter, left ventricular end-diastolic diameter, left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and cardiac index (CI) were measured by echocardiography.

RESULTS

The concentrations of serum h-FABP and BNP in patients with CHF were significantly higher than in the control group (21.7 ± 4.3 ng/mL vs. 6.3 ± 1.7 ng/mL, 582.4 ± 180.6 pg/mL vs.31.2 ± 9.8 pg/mL, all P < 0.01), positively correlated with the degree of heart failure (all P < 0.01), and were both higher in groups endocardial fibroelastosis and dilated cardiomyopathy than in the control group (all P < 0.01), but there was no statistically significant difference between the 2 groups (P > 0.05). h-FABP concentration in patients with CHF was positively correlated with BNP (r = 0.78, P < 0.01) but negatively correlated with LVEF, LVFS, and CI (r = -0.65, -0.64, and -0.71, respectively; all P < 0.01). BNP concentration was also negatively correlated with LVEF, LVFS, and CI (r = -0.75, -0.61, and -0.79, respectively; all P<0.01). After treatment with carvedilol, the serum concentrations of h-FABP and BNP in group A were lower than in group B, and the magnitude of heart rate reduction, improvement of LVEF, LVFS, and CI, and reduction of left ventricular end-systolic diameter and left ventricular end-diastolic diameter in group A were all greater than in group B (all P < 0.01). Treatment with carvedilol had no adverse events.

CONCLUSIONS

Serum concentrations of h-FABP and BNP can be used as biomarkers to evaluate the severity of heart failure, and carvedilol can significantly improve heart function in children with CHF.

Phase II trial of trastuzumab in combination with cytotoxic chemotherapy for treatment of metastatic osteosarcoma with human epidermal growth factor receptor 2 overexpression: a report from the children's oncology group

PURPOSE

Despite efforts to intensify chemotherapy, survival for patients with metastatic osteosarcoma remains poor. Overexpression of human epidermal growth factor receptor 2 (HER2) in osteosarcoma has been shown to predict poor therapeutic response and decreased survival. This study tests the safety and feasibility of delivering biologically targeted therapy by combining trastuzumab with standard chemotherapy in patients with metastatic osteosarcoma and HER2 overexpression.

PATIENTS AND METHODS

Among 96 evaluable patients with newly diagnosed metastatic osteosarcoma, 41 had tumors that were HER2-positive by immunohistochemistry. All patients received chemotherapy with cisplatin, doxorubicin, methotrexate, ifosfamide, and etoposide. Dexrazoxane was administered with doxorubicin to minimize the risk of cardiotoxicity from treatment with trastuzumab and anthracycline. Only patients with HER2 overexpression received concurrent therapy with trastuzumab given for 34 consecutive weeks.

RESULTS

The 30-month event-free and overall survival rates for patients with HER2 overexpression treated with chemotherapy and trastuzumab were 32% and 59%, respectively. For patients without HER2 overexpression, treated with chemotherapy alone, the 30-month event-free and overall survival rates were 32% and 50%, respectively. There was no clinically significant short-term cardiotoxicity in patients treated with trastuzumab and doxorubicin.

CONCLUSION

Despite intensive chemotherapy plus trastuzumab for patients with HER2-positive disease, the outcome for all patients was poor, with no significant difference between the HER2-positive and HER2-negative groups. Although our findings suggest that trastuzumab can be safely delivered in combination with anthracycline-based chemotherapy and dexrazoxane, its therapeutic benefit remains uncertain. Definitive assessment of trastuzumab's potential role in treating osteosarcoma would require a randomized study of patients with HER2-positive disease.

B-type natriuretic peptide and amino-terminal pro-B-type natriuretic peptide in pediatric patients with pulmonary arterial hypertension

OBJECTIVES

B-type natriuretic peptide (BNP) and the amino-terminal fragment (NTproBNP) correlate with clinical variables, but have not been simultaneously studied in a large number of pediatric patients with pulmonary arterial hypertension (PAH). The purpose of our investigation was to compare BNP and NTproBNP with clinical indicators of disease in a pediatric PAH population for which biomarkers are much needed.

DESIGN

We retrospectively compared BNP and NTproBNP levels with exercise capacity, echocardiographic data, and hemodynamics in PAH patients under 21 years old. Two hundred sixty-three blood samples from 88 pediatric PAH patients were obtained, with BNP and NTproBNP drawn at the same time.

RESULTS

There was a correlation between BNP and NTproBNP with mean pulmonary arterial pressure/mean systemic arterial pressure ratio (r= 0.40, P < .01; r= 0.45, P < .01; respectively), mean right atrial pressure (r= 0.48, P < .01; r= 0.48, P < .01), and tricuspid regurgitant velocity (r= 0.36, P < .01; r= 0.41, P < .01). BNP and NTproBNP are associated with 6-minute walk distance, mean pulmonary arterial pressure, mean pulmonary arterial pressure/mean systemic arterial pressure ratio, mean right atrial pressure, pulmonary vascular resistance index, and tricuspid regurgitant velocity when investigated longitudinally. On the average, a 1-unit increase in log BNP or NTproBNP was associated with 4.5 units × m(2) or 3.4 units × m(2) increase in pulmonary vascular resistance index, respectively. There was a strong correlation between log BNP and log NTproBNP measurements (r= 0.87, P < .01).

CONCLUSION

In pediatric PAH, BNP and NTProBNP are strongly correlated and predict changes in clinical variables and hemodynamics. In a cross-sectional analysis, NTproBNP correlated with echocardiographic and exercise data better than BNP; NTproBNP showed less within patient variability over time; therefore, NTproBNP can add additional information toward predicting these clinical measurements.

N-terminal pro-brain natriuretic peptide level as a screening tool for cardiac involvement in paediatric diseases of extracardiac origin

BACKGROUND

Serum concentrations of N-terminal natriuretic pro-brain natriuretic peptide (NT-proBNP) correlate well with the severity of cardiac disease in children and adults. There are also paediatric illnesses of extracardiac origin that may cause deterioration of the cardiac function in some patients (pts). A high NP level can signify a concomitant cardiac involvement in respiratory distress, or secondary to a systemic disease.

OBJECTIVE

To assess the potential of NT-proBNP as a screening tool for cardiac involvement in paediatric diseases of extracardiac origin.

METHODS

A literature search was performed in PubMed for the relevant studies with the subject brain natriuretic peptide (BNP) and NT-proBNP from 1995 to 2010 with stress on characteristics of the natriuretic peptides, paediatric reference values and systemic paediatric diseases with potential influence on the myocardial performance. The main focus has been NT-proBNP being the most stable NP and correlating well with BNP.

RESULTS

Most studies agree that a high NT-proBNP level indicates cardiac dysfunction in different systemic diseases such as thalassemia and cystic fibrosis or in pts after chemotherapy. In special clinical scenarios as sepsis or respiratory distress, NT-proBNP helps to narrow down the differential diagnosis or can be used for risk stratification.

CONCLUSION

NT-proBNP can serve as a screening tool in various primarily non-cardiac paediatric diseases. Together with the clinical picture, a high level suggests further assessment by a paediatric cardiologist.

Reference intervals for brain natriuretic peptide in healthy newborns and infants measured with an automated immunoassay platform

BACKGROUND

In order to assess the reference intervals for B-type natriuretic hormone (BNP) in the first days of life, we measured peptide concentrations using the fully automated Access platform.

METHODS

Plasma BNP was measured in 188 apparently healthy newborns and infants throughout the first month of extra-uterine life, as well as in 245 healthy infants ranging from 1 month to 12 years of age.

RESULTS

BNP showed the highest concentrations in the first 2 days of life, with a progressive decline afterwards. Moreover, BNP values in the first week of life were significantly higher (p<0.0001) than values observed in the next periods. As a result, a significant negative correlation was found between BNP and age values when considering all 433 samples (rho=-0.816, p<0.0001 by the Spearman rank correlation test). There was no significant difference between BNP values found in males and females.

CONCLUSIONS

According to this data, our study indicates that at least two reference intervals should be used for newborns and infants. The first, with higher BNP values for neonates in the first week of extra-uterine life, and the other, with lower BNP values for infants aged 2 weeks to 12 years.

Early markers of cardiovascular dysfunction in young girls affected by Cushing's syndrome before and after successful cure

BACKGROUND

even after successful surgical cure, Cushing's Syndrome (CS) may induce cardiovascular (CV) diseases including hypertension, or elicit onset of CV risk factors, such as obesity.

OBJECTIVES

to evaluate some early markers of CV dysfunction in adolescent girls before and after successful surgical cure of CS; to compare after surgery data with those of a control group (C) of healthy young girls.

METHODS

23 girls affected by CS were enrolled (range: 11-17 years; mean: 14.3 +/- 1.7 years). Epicardial fat thickness (EFT), intima-media thickness (IMT), N-terminal pro B-type natriuretic peptide (NT-proBNP) were assessed; transthoracic echocardiogram coupled with Tissue Doppler imaging (TDI) was performed. RESULTS (CS before surgery vs. CS after surgery): EFT (p < 0.05). (CS after surgery vs. C): EFT (p = 0.0001); IMT (p = 0.0001); NT-proBNP (p = 0.0001). TDI: isovolumetric relaxation time (p = 0.001); isovolumetric contraction time (p = 0.001); myocardial performance index (p = 0.001). Significant correlations: NT-proBNP with IRT (r = 0.45, p = 0.026 ), ICT (r = 0.47, p = 0.028), and myocardial performance index (r = 0.51, p = 0.0032).

CONCLUSIONS

important structural and functional modifications of heart and vessels are present in young female CS despite successful surgical cure, even in paediatric age. It underlines their significantly higher cardiovascular risk. Our findings confirm that EFT, IMT, NT-proBNP and TDI diastolic parameters, not previously tested in paediatric CS, are early markers of cardiovascular dysfunction. Because of its relationship with TDI, the assessment of NT-proBNP proves to be the best marker in detecting a cardiovascular dysfunction in this specific population.