N-terminal pro-B-type natriuretic peptide: reference plasma levels from birth to adolescence. Elevated levels at birth and in infants and children with heart diseases

The Trend of Urinary N Terminal Probrain Natriuretic Peptide in Extremely Low Birth Weight Infants during the Neonatal Period

OBJECTIVE

N-terminal probrain natriuretic peptide (NT-proBNP) is a biomarker of interest in many cardiopulmonary diseases in extremely low birth weight (ELBW) Infants. However, there is a gap in knowledge about the trend of ELBW infant's urinary NT-proBNP during the neonatal period.

AIM

To determine the trend of urinary NT-proBNP during the first 4 weeks of life of an ELBW infant.

STUDY DESIGN

We analyzed prospectively enrolled 87 ELBW infants. Urinary NT-proBNP to creatinine ratios were measured on days 1 to 7, 14, and 28 of life. We plotted each study point's means to determine the trend of urinary NT-proBNP over the entire neonatal period. Data were analyzed using the Friedman analysis of variance for comparative analysis of study points.

RESULTS

Urinary NT-proBNP/creatinine ratios were significantly elevated on days 1 to 7 (mean 2,452, ± 1,518) than day 14 (mean 747, ± 176), and day 28 (mean 149, ± 54), p = 0.001. Overall, urinary NT-proBNP levels were highest during days 1 to 3 (mean 3,232, ± 1,255) and lowest on day 28 (mean 149, ± 54).

CONCLUSION

Urinary NT-proBNP levels are higher during the first week in ELBW infants with a downward trend during the neonatal period, the lowest values at 4 weeks postnatal age. More studies are required to determine the clinical utility of this trend during and beyond the neonatal period.

KEY POINTS

· NT-proBNP is a biomarker for monitoring cardiac disease in premature infants.. · The trend of urinary NT-proBNP is unknown in premature infants.. · A trend of urinary NT-proBNP was determined during the first 4 weeks in premature infants..

Plasma Brain Natriuretic Peptide Levels in Children with Chronic Kidney Disease and Renal Transplant Recipients: A Single Center Study

Pediatric chronic kidney disease (CKD) patients, as well as kidney transplant patients, are at an increased risk of developing cardiovascular disease. BNP measurement, as a biomarker of cardiovascular risk, has been recommended to this high-risk population. Plasma BNP levels were measured in 56 CKD children in either pre-dialysis stage, hemodialysis (HD) or renal transplant recipients (RTRs) and in 76 sex- and age-matched healthy controls. BNP levels were investigated in HD children, before and after the completion of their HD session. BNP levels in total CKD population, in pre-dialysis stage patients and on HD were significantly higher, compared to the respective controls. HD children had higher BNP levels compared to CKD patients in the pre-dialysis stage. Moreover, post-HD BNP concentration was slightly higher than pre-HD, with the difference being marginally statistically significant. BNP was positively correlated with eGFR, creatinine, cystatin-C and parathormone and negatively with albumin and 25-hydroxyvitamin D. A positive correlation between BNP concentration and the ratio of E/A in pulse-wave Doppler echocardiography was also observed. In conclusion, CKD pediatric patients, mainly those undergoing HD, have high plasma BNP levels which do not decrease after the HD session. This is indicative of a greater risk for future cardiovascular disease.

NT-proBNP Concentrations in the Umbilical Cord and Serum of Term Neonates: A Systematic Review and Meta-Analysis

The detection of NT-proBNP levels both in umbilical cord blood (UCB) samples and in serum samples collected from healthy term neonates during the neonatal period. A systematic review of relevant literature in accordance with PRISMA guidelines was conducted. For quality appraisal, the potential risk of bias was assessed using the BIOCROSS evaluation tool. The random-effects and fixed-effects models were used to calculate weighted mean differences with a corresponding 95% confidence interval. A total of forty (40) studies met the inclusion criteria for the systematic review. After further examination, eighteen (18) studies (1738 participants) from the UCB sample group and fourteen (14) studies (393 participants) from the serum sample group were selected to perform a meta-analysis. Using the fixed-effects model, the mean intervals of NT-proBNP in UCB and serum samples were 492 pg/mL (95% CI: 480−503 pg/mL) and 1341 pg/mL (95% CI: 1286−1397 pg/mL), respectively. A higher concentration of ΝΤ-proBNP was observed in the serum sample group compared to the UCB samples (p < 0.001). We present the intervals of NT-proBNP in UCB and in the serum of healthy term neonates. The determination of the potential effect of perinatal factors on the biomarker’s reference range was also aimed.

Early N-Terminal Pro B-Type Natriuretic Peptide (NTproBNP) Plasma Values and Associations with Patent Ductus Arteriosus Closure and Treatment-An Echocardiography Study of Extremely Preterm Infants

The aim was to investigate the association of gestational age (GA), echocardiographic markers and levels of plasma N-terminal pro-B-type natriuretic peptide (NTproBNP) with the closure rate of a haemodynamically significant patent ductus arteriosus (hsPDA). Ninety-eight Swedish extremely preterm infants, mean GA 25.7 weeks (standard deviation 1.3), born in 2012–2014, were assessed with echocardiography and for levels of NTproBNP. Thirty-three (34%) infants had spontaneous ductal closure within three weeks of age. Infants having spontaneous closure at seven days or less had significantly lower NTproBNP levels on day three, median 1810 ng/L (IQR 1760–6000 ng/L) compared with: infants closing spontaneously later, 10,900 ng/L (6120–19,200 ng/L); infants treated either with ibuprofen only, 14,600 ng/L (7740–28,100 ng/L); or surgery, 32,300 ng/L (29,100–35,000 ng/L). Infants receiving PDA surgery later had significantly higher NTproBNP values on day three than other infants. Day three NTproBNP cut-off values of 15,001–18,000 ng/L, predicted later PDA surgery, with an area under the curve in ROC analysis of 0.69 (0.54–0.83). In conclusion, the spontaneous PDA closure rate is relatively high in extremely preterm infants. Early NTproBNP levels can be used with GA in the management decisions of hsPDA.

Acute Myocarditis in Children: An Overview of Treatment and Recent Patents

BACKGROUND

Pediatric myocarditis is rare but challenging. This overview summarized the current knowledge and recent patents on childhood myocarditis.

METHODS

Clinical queries and keywords of "myocarditis" and "childhood" were used as search engine.

RESULTS

Viral infections are the most common causes of acute myocarditis. Affected children often have a prodrome of fever, malaise, and myalgia. Clinical manifestations of acute myocarditis in children can be nonspecific. Some children may present with easy fatigability, poor appetite, vomiting, abdominal pain, exercise intolerance, respiratory distress/tachypnea, dyspnea at rest, orthopnea, chronic cough with wheezing, chest pain, unexplained tachycardia, hypotension, syncope, and hepatomegaly. Supraventricular arrhythmias, ventricular arrhythmias, and heart block may be present. A subset of patients have fulminant myocarditis and present with cardiovascular collapse, which may progress to severe cardiogenic shock, and even death. A high index of suspicion is crucial to its diagnosis and timely management. Cardiac magnetic resonance imaging is important in aiding clinical diagnosis while, endomyocardial biopsy remains the gold standard. The treatment consists of supportive therapy, ranging from supplemental oxygen and fluid restriction to mechanical circulatory support. Angiotensinconverting enzyme inhibitors, angio-tensin II receptor blockers, β-blockers, and aldosterone antagonists might be used for the treatment of heart failure while, immunosuppression treatments remain controversial. There are a few recent patents targeting prevention or treatment of viral myocarditis, including an immunogenic composition comprising a PCV-2 antigen, glutathione-S-transferase P1, neuregulins, NF-[kappa] B inhibitor, a pharmaceutical composition which contains 2-amino-2- (2- (4-octyl phenyl) - ethyl) propane 1,3-diol, a composition containing pycnojenol, Chinese herbal concoctions, and a Korean oral rapamycin. Evidence of their efficacy is still lacking.

CONCLUSION

This article reviews the current literature regarding etiology, clinical manifestations, diagnosis, and management of acute myocarditis in children.

Prenatal Particulate Matter (PM) Exposure and Natriuretic Peptides in Newborns from Mexico City

(1) Background: The aim of this study was to assess associations between particulate matter (PM) exposure and natriuretic peptide concentrations in cord blood from newborns. (2) Methods: we conducted a cross-sectional study in Mexico City with 101 pregnant women from CIMIGEN Hospital. Atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) were measured in plasma from cord blood in 51 newborns by ELISA. We estimated PM exposure (PM2.5 and PM10) at first, second and third trimester of pregnancy. (3) Results: The median and interquartile range for ANP, BNP and CNP plasma concentrations were 66.71 (46.92-80.23), 98.23 (73.64-112.30) and 1129.11 (944.10-1452.02) pg/mL, respectively. PM2.5 and PM10 levels for the whole pregnancy period were 22.2 µg/m³ and 41.63 µg/m³, respectively. Employing multivariable linear regression models adjusted for maternal age, newborn sex, smoking before pregnancy, maternal occupation and newborns' length and height, we observed a 2.47 pg/mL (95%CI: -4.67, -0.27) decrease in BNP associated with PM2.5 exposure during second trimester. Adjusted for the same set of confounders, third trimester PM10 exposure was inversely associated with ANP concentrations (beta estimate: -0.90; 95% CI: -1.80, -0.03). Neither PM10 nor PM2.5 were associated with CNP at any trimester of pregnancy. (4) Conclusions: Prenatal exposure to particulate matter was associated with ANP and BNP decrease in newborns.

The different manifestations of COVID-19 in adults and children: a cohort study in an intensive care unit

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has collapsed health systems worldwide. In adults, the virus causes severe acute respiratory distress syndrome (ARDS), while in children the disease seems to be milder, although a severe multisystem inflammatory syndrome (MIS-C) has been described. The aim was to describe and compare the characteristics of the severe COVID-19 disease in adults and children.

Methods

This prospective observational cohort study included the young adults and children infected with SARS-CoV-2 between March–June 2020 and admitted to the paediatric intensive care unit. The two populations were analysed and compared focusing on their clinical and analytical characteristics and outcomes.

Results

Twenty patients were included. There were 16 adults (80%) and 4 children (20%). No mortality was recorded.

All the adults were admitted due to ARDS. The median age was 32 years (IQR 23.3–41.5) and the most relevant previous pathology was obesity (n = 7, 43.7%). Thirteen (81.3%) needed mechanical ventilation, with a median PEEP of 13 (IQR 10.5–14.5). Six (37.5%) needed inotropic support due to the sedation. Eight (50%) developed a healthcare-associated infection, the most frequent of which was central line-associated bloodstream infection (n = 7, 71.4%). One patient developed a partial pulmonary thromboembolism, despite him being treated with heparin.

All the children were admitted due to MIS-C. Two (50%) required mechanical ventilation. All needed inotropic support, with a median vasoactive-inotropic score of 27.5 (IQR 17.5–30).

The difference in the inotropic requirements between the two populations was statistically significant (37.5% vs. 100%, p < 0.001). The biomarker values were higher in children than in adults: mid-regional pro-adrenomedullin 1.72 vs. 0.78 nmol/L (p = 0.017), procalcitonin 5.7 vs. 0.19 ng/mL (p = 0.023), and C-reactive protein 328.2 vs. 146.9 mg/L (p = 0.005). N-terminal pro-B-type natriuretic peptide and troponins were higher in children than in adults (p = 0.034 and p = 0.039, respectively).

Conclusions

Adults and children had different clinical manifestations. Adults developed severe ARDS requiring increased respiratory support, whereas children presented MIS-C with greater inotropic requirements. Biomarkers could be helpful in identifying susceptible patients, since they might change depending on the clinical features.

Continuous, complete and comparable NT-proBNP reference ranges in healthy children

Background

NT-proBNP is one of the most important biomarkers for the diagnosis and risk assessment of heart failure in adults. Age- and gender-independent reference intervals (RIs) have been reported. In contrast, RIs in children are strongly age-dependent, do not exist for all ages and reveal a right-skewed distribution. Accordingly, no common Z-score can be formed and a cross-age interpretive method, so far, is missing.

Methods

Within the paper on hand, new evaluation techniques are applied to already published NT-proBNP study results and additionally to newly gained data. Upper limits (ULs), lower limits (LLs) and 50th percentiles are tested for power-like behavior as a function of age using linear regression analysis. Functions for continuous RIs are derived and reference limits are calculated on a per day basis. A corresponding Zlog formula is deduced and its usefulness is stated in two clinical examples.

Results

The power-like behavior of NT-proBNP concentration from birth to 18 years is demonstrated. With age in days t and measured NT-proBNP value x in pg/mL, an age-specific Zlog value may directly be calculated using the equation:

Zlog NT-proBNP = log   x + 0.512 ⋅ log   t − 3.417 1.489 + 0.014 ⋅ log   t ⋅ 3.92 ${\rm{Zlo}}{{\rm{g}}_{{\rm{NT - proBNP}}}} = {{\log \;x + 0.512 \cdot \log \;t - 3.417} \over {1.489 + 0.014 \cdot \log \;t}} \cdot 3.92$

Conclusions

Using formulas for UL and LL, continuous RIs from 0 to 18 years may be obtained. Continuity corresponds to physiological changes in the body much better than discrete RIs. With the advent of an NT-proBNP-specific Zlog value, a cross-age Z-score equivalent is providing an easy interpretation aid in everyday pediatric practice. This new approach allows to identify clinical worsening much better, sooner and more clearly than previous absolute values.

Role of NT-proBNP in the prediction of moderate to severe Bronchopulmonary Dysplasia in preterm infants

OBJECTIVE

The objective of the study was to determine the clinical utility of brain natriuretic peptide (NT-proBNP) for prediction of moderate to severe bronchopulmonary dysplasia (BPD). We hypothesized that elevated NT-proBNP levels at 4 weeks of postnatal age may predict the severity of BPD in preterm infants.

STUDY DESIGN

The study design was a prospective observational study. The research team enrolled and followed a cohort of 70 infants with gestational age less than or equal to 30 weeks. The plasma NT-proBNP levels were measured at the postnatal day 28th. We further followed and categorized infants into two groups. Infants with no or mild BPD (Group 1) and infants with moderate or severe BPD (Group 2). We compared plasma NT-proBNP levels at 28th day of postnatal life between Groups 1 and 2. The difference in NT-proBNP levels on day 28th between groups was used to predict the severity of BPD.

RESULTS

Plasma NT-proBNP was significantly elevated in Group 2 compared with Group 1, median (IQR) of 845 pg/mL (553, 1632) compared with 726 pg/mL (391, 923), P = 0.02. NT-proBNP had a fair predictive accuracy (C statistics of 0.68) to determine moderate to severe BPD.

CONCLUSION

NT-proBNP may be a useful biomarker in conjunction with clinical factors as a predictor of severe BPD. For future directions, the trend of NT-proBNP in infants with BPD may have clinical significance in monitoring of the disease.

Establishment of normal reference values of NT-proBNP and its application in diagnosing acute heart failure in children with severe hand foot and mouth disease [corrected]

Hand, foot, and mouth disease (HFMD), caused by enteroviruses, is an acute contagious disease in children. Some severe infections caused by human enterovirus 71 (HEV71) lead to rapid death in children with acute heart failure (HF). N-terminal probrain natriuretic peptide (NT-proBNP) is an important indicator of HF; however, its normal reference values in children and role in HFMD remain unclear.This study aimed to investigate the correlation between NT-proBNP and heart function and establish normal reference values of NT-proBNP in children with HFMD aged 0 to 18 years.In this study, 95% normal reference values were established in 1031 healthy children aged 0 to 18 years. The correlation between NT-proBNP and left ventricular ejection (LVEF) was analyzed in 392 children with HFMD using Spearman correlation and receiver operating characteristic analysis.NT-proBNP levels were negatively correlated with LVEF in 392 children with HFMD. The median NT-proBNP level was 921 pg/mL in the early cardiorespiratory failure group, but only 55 pg/mL in the nervous system involvement group. Serum NT-proBNP levels were negatively correlated with age. The normal reference value in the neonatal period (0 to <1 month) and adolescence (13-18 years) was 250.0 to 3987.0 pg/mL and 20.0 to 145.0 pg/mL, respectively.NT-proBNP levels can reflect the severity of HFMD and discriminate the second stage from the third stage of HFMD effectively. NT-proBNP is a useful biomarker to predict the early stage of severe HFMD in children with HF. Different ages fit with different normal reference values of NT-proBNP in children.

Cardiac biomarkers and haemodynamically significant patent ductus arteriosus in preterm infants

Accurately defining haemodynamically significant patent ductus arteriosus (PDA) in preterm infants who are at risk of PDA related morbidities are active areas of neonatal research. Natriuretic peptides are cardiac hormones that respond to volume and pressure loading, with elevated plasma levels found in infants with PDA. In the preterm neonatal setting, studies to date have predominantly investigated the ability of these biomarkers to discriminate between infants with and without a PDA at various postnatal ages. Their clinical utility has therefore been exclusively evaluated as a method of triaging cases of suspected hsPDA to decrease the need for echocardiograms, and to monitor treatment response. Biomarkers are yet to be robustly investigated for their ability to predict important PDA associated morbidities. In this review, we examine the most recent literature to date on the use of biomarkers in the management of PDA.

The diagnostic value of plasma N-terminal connective tissue growth factor levels in children with heart failure

OBJECTIVE

The aim of this study was to assess the diagnostic value of plasma N-terminal connective tissue growth factor in children with heart failure. Methods and results Plasma N-terminal connective tissue growth factor was determined in 61 children, including 41 children with heart failure, 20 children without heart failure, and 30 healthy volunteers. The correlations between plasma N-terminal connective tissue growth factor levels and clinical parameters were investigated. Moreover, the diagnostic value of N-terminal connective tissue growth factor levels was evaluated. Compared with healthy volunteers and children without heart failure, plasma N-terminal connective tissue growth factor levels were significantly elevated in those with heart failure (p0.05), but it obviously improved the ability of diagnosing heart failure in children, as demonstrated by the integrated discrimination improvement (6.2%, p=0.013) and net re-classification improvement (13.2%, p=0.017) indices.

CONCLUSIONS

Plasma N-terminal connective tissue growth factor is a promising diagnostic biomarker for heart failure in children.

Cardiac biomarkers in pediatric heart disease: A state of art review

Every year there are more than 11000 hospitalizations related to heart failure in children resulting in significant morbidity and mortality. Over the last two decades, our understanding, diagnosis and management of pediatric heart failure is evolving but our ability to prognosticate outcomes in pediatric heart acute heart failure is extremely limited due to lack of data. In adult heart failure patients, the role of cardiac biomarkers has exponentially increased over the last two decades. Current guidelines for management of heart failure emphasize the role of cardiac biomarkers in diagnosis, management and prognostication of heart failure. It is also noteworthy that these biomarkers reflect important biological processes that also open up the possibility of therapeutic targets. There is however, a significant gap present in the pediatric population with regards to biomarkers in pediatric heart failure. Here, we seek to review available data regarding cardiac biomarkers in the pediatric population and also explore some of the emerging biomarkers from adult literature that may be pertinent to pediatric heart failure.

Endurance Exercise Training in Young Adults with Barth Syndrome: A Pilot Study

BACKGROUND

Barth syndrome (BTHS) is a rare X-linked disorder that is characterized by mitochondrial abnormalities, cardio-skeletal myopathy, exercise intolerance, and premature mortality. The effect on endurance exercise training on exercise tolerance, cardio-skeletal function, and quality of life in BTHS is unknown.

METHODS

Four young adults (23 ± 5 years, n = 4) with BTHS participated in a 12-week, supervised, individualized endurance exercise training program. Exercise training was performed on a cycle ergometer for 30-45' three times per week at a moderate intensity level. Exercise tolerance was measured by graded exercise testing and peak oxygen consumption, heart function via two-dimensional and M-mode echocardiography, skeletal muscle function by near-infrared spectroscopy, and quality of life through the Minnesota Living with Heart Failure questionnaire.

RESULTS

There were no adverse events during exercise testing or training for any participant. Peak oxygen consumption modestly (~5%) improved in three or four participants. Mean quality of life questions regarding dyspnea and side effects from medications significantly improved following exercise training. Mean resting heart function or skeletal muscle oxygen extraction during exercise did not improve after exercise training.

CONCLUSION

Endurance exercise training is safe and appears to modestly improve peak exercise tolerance and certain measures of quality of life in young adults with BTHS. However, compared to improvements resulting from endurance exercise training seen in other non-BTHS mitochondrial myopathies and heart failure, these improvements appear blunted. Further research into the most beneficial mode, intensity and frequency of exercise training in BTHS is warranted.

B-Type Cardiac Natriuretic Peptides in the Neonatal and Pediatric Intensive Care Units

During the last decade, interest in the brain natriuretic peptide (BNP) and N-terminal probrain natriuretic peptide (NT-proBNP) in the pediatric population has progressively increased. The aim of this article is to provide an up to date review of evidences regarding the use of BNP/NT-proBNP in pediatrics, with a particular focus on neonatal intensive care and congenital heart disease. The potentialities of the BNP have been demonstrated in multiple settings, particularly: the screening of congenital/acquired heart disease (CHD) versus pulmonary disease; the evaluation of CHD severity (grade of heart failure, degree of left-to-right shunts); the management of children undergoing cardiac surgery; and monitoring premature infants with patent arterial duct. BNP/NT-proBNP values may be considered an easy and relatively low cost additional diagnostic and prognostic tool. Interpretation of BNP values in children requires attention to important factors, including: laboratory methods, the type of cardiac defect, its severity, and the presence of extracardiac conditions. Of these, the hemodynamic characteristic of CHD and physiologic variations of BNP values occurring during the first weeks of life play a major role. The current evidences in favor of BNP use are mainly derived from single-center, nonrandomized studies, and cost-effectiveness analysis are still lacking. As such, despite sufficient evidences supporting the diagnostic and prognostic potentialities of BNP, these findings should be reinforced by multicenter, randomized studies specifically designed to evaluate outcomes and cost-effectiveness. In addition, standard consensus documents/guidelines, that are currently lacking, are warranted for a more systematic use of BNP in the pediatric age.

Distribution of circulating cardiac biomarkers in healthy children: from birth through adulthood

Aim: While circulating biomarkers are critical tools for cardiovascular adult care, their relevance in childhood is unknown. Methods: We evaluated the behavior of plasma concentrations of clinically relevant cardiac biomarkers (NT-proBNP, hs-cTnI, sST2, Galectin-3) in 106 healthy children. Results: Subjects were divided into age subgroups: 24 newborns (0–30 days), 26 infants (1–12 months), 30 children (1–12 years) and 26 adolescents (13–18 years). Healthy adults were used as control. NT-proBNP (newborns: 504.3 [211.07–942.7] ng/L, median [25–75 percentiles]; infants: 200.64 [76.88–306.73]; children: 97.27 [49.24–271.80]; adolescents: 24.35 [13.14–58.83]; p < 0.001) and hs-cTnI (newborns: 9.3 [3.3–93.8] ng/L; infants: 13.8 [4.82–72.52]; children: 11.45 [4.0–48.10]; adolescents: 2.6[2.07–3.90]; p < 0.001) were highest in the first month of life, showing a decline in the next years. sST2 and Galectin-3 showed no differences. Conclusion: Changes in hs-cTnI and NT-proBNP suggest the design of age- and sex-based reference intervals that will have to be explored in a larger population.

Pro-brain natriuretic peptide (ProBNP) levels in North Indian children with Kawasaki disease

The diagnosis of Kawasaki disease (KD), a common pediatric vasculitis, is based solely on clinical criteria. There is a need for a robust laboratory marker that can help differentiate KD from other acute, febrile, childhood illnesses and also to predict cardiac involvement. We conducted a cross-sectional study of 25 consecutive patients admitted with diagnosis of KD from January 2013 to April 2014 and compared them with age- and sex-matched febrile controls. We studied the serum pro-brain natriuretic peptide (ProBNP) [ProBNP and N-terminal pro-B-type natriuretic peptide (NT-ProBNP) levels], a marker of myocardial dysfunction, in children with KD in acute and convalescent phases of disease. These levels were also estimated in febrile controls for comparison. The ProBNP (ProBNP and NT-ProBNP) levels were much higher in the acute phase of the KD patients compared to levels in the convalescent phase of KD (p = 0.000014). Similarly, the levels in the acute phase were higher when compared to the age- and sex-matched febrile controls (p = 0.000126). The receiver operating curve (ROC) analysis for the ProBNP levels in the acute phase of KD yielded an area under the curve of 0.954 ± 0.034 (p < 0.000, 95 % CI 0.886-1.0). Based on ROC analysis, a cutoff of 1025 pg/mL for ProBNP levels in the acute phase of KD had 88 % sensitivity and 96 % specificity for the diagnosis of KD. A lower cut-off of 514 pg/mL yielded a 100 % sensitivity and 80 % specificity for the diagnosis of KD. The ProBNP levels were higher in those with coronary artery abnormalities (CAA) compared to those without CAA in both acute (p = 0.013) and convalescent (p = 0.045) phases. ProBNP levels may be used as a surrogate marker for the differentiation of KD from other febrile, infectious illnesses and may also predict the involvement of coronary arteries.

Cardiac biomarkers in children with congenital heart disease

BACKGROUND

Most congenital heart diseases (CHDs) have specific hemodynamics, including volume and pressure overload, as well as cyanosis and pulmonary hypertension, associated with anatomical abnormalities. Such hemodynamic abnormalities can cause activation of neurohormones, inflammatory cytokines, fibroblasts, and vascular endothelial cells, which in turn contribute to the development of pathologic conditions such as cardiac hypertrophy, fibrosis, and cardiac cell damages and death. Measuring biomarker levels facilitates the prediction of these pathological changes, and provides information about the stress placed on the myocardial cells, the severity of the damage, the responses of neurohumoral factors, and the remodeling of the ventricle. Compared to the ample information on cardiac biomarkers in adult heart diseases, data from children with CHD are still limited.

DATA SOURCES

We reviewed cardiac biomarkers-specifically focusing on troponin as a biomarker of myocardial damage, amino-terminal procollagen type III peptide (PIIIP) as a biomarker of myocardial fibrosis and stromal remodeling, and B-type natriuretic peptide (BNP)/N-terminal proBNP as biomarkers of cardiac load and heart failure, by introducing relevant publications, including our own, on pediatric CHD patients as well as adults.

RESULTS

Levels of highly sensitive troponin I are elevated in patients with atrial septal defects (ASDs) and ventricular septal defects (VSDs). PIIIP levels are also elevated in patients with ASD, VSD, pulmonary stenosis, and Tetralogy of Fallot. Measurement of BNP and N-terminal proBNP levels shows good correlation with heart failure score in children.

CONCLUSIONS

In the treatment of children with CHD requiring delicate care, it is vital to know the specific degree of myocardial damage and severity of heart failure. Cardiac biomarkers are useful tools for ascertaining the condition of CHDs with ease and are likely to be useful in determining the appropriate care of pediatric cardiology patients.

The untapped potential of proteomic analysis in pediatric pulmonary hypertension

Analysis of the human proteome has become increasingly sophisticated, and offers invaluable potential insight into the pathophysiology of human disease. The increasing standardization of methods, speed, and sophistication of mass spectrometric analysis, availability of reliable antibodies, and dissemination of information among the scientific community has allowed for exponential growth of our knowledge base. The continued effort to provide a molecular explanation for future medical applications based on biomarker discovery is epitomized by the outstanding efforts of the human proteome project, whose goal is to generate a map of the human proteome. However, proteomic analysis is underrepresented in pediatric illness; given the unique challenges of research in the pediatric population, proteomic analysis represents enormous untapped potential, especially in the further elucidation of the pathophysiology of rare diseases such as pulmonary hypertension (PH). In this article, we will describe the unique challenge of pediatric research, the importance of alternative avenues such as proteomics for in-depth analysis of pediatric pathobiology at the cellular level, the specific need for proteomic investigation of pediatric PH, the current status of PH proteomics, and future directions.

Proteomics of pediatric heart failure: from traditional biomarkers to new discovery strategies

Heart failure in children is a complex clinical syndrome with multiple aetiologies. The underlying disorders that lead to heart failure in children differ significantly from those in adults. Some clinical biomarkers for heart failure status and prognosis appear to be useful in both age groups. This review outlines the use and the present status of biomarkers for heart failure in paediatric cardiology. Furthermore, clinical scenarios in which development of new biomarkers might address management or prognosis are discussed. Finally, strategies for proteomic discovery of novel biomarkers and application to practice are described.

BNP in children with congenital cardiac disease: is there now sufficient evidence for its routine use?

Interest in brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the management of children with CHD has increased. There are, however, no current guidelines for their routine use. The aim of this review article is to provide an update on the data regarding the use of BNP/NT-proBNP in the evaluation and surgical treatment of children with CHD. BNP/NT-proBNP levels in children with CHD vary substantially according to age, laboratory assay methods, and the specific haemodynamics associated with the individual congenital heart lesion. The accuracy of BNP/NT-proBNP as supplemental markers in the integrated screening, diagnosis, management, and follow-up of CHD has been established. In particular, the use of BNP/NT-proBNP as a prognostic indicator in paediatric cardiac surgery has been widely demonstrated, as well as its role in the subsequent follow-up of surgical patients. Most of the data, however, are derived from single-centre retrospective studies using multivariable analysis; prospective, randomised clinical trials designed to evaluate the clinical utility and cost-effectiveness of routine BNP/NT-proBNP use in CHD are lacking. The results of well-designed, prospective clinical trials should assist in formulating guidelines and expert consensus recommendations for its use in patients with CHD. Finally, the use of new point-of-care testing methods that use less invasive sampling techniques - capillary blood specimens - may contribute to a more widespread use of the BNP assay, especially in neonates and infants, as well as contribute to the development of screening programmes for CHD using this biomarker.

Diagnosing significant PDA using natriuretic peptides in preterm neonates: a systematic review

BACKGROUND AND OBJECTIVES

Echocardiogram is the gold standard for the diagnosis of hemodynamically significant patent ductus arteriosus (hsPDA) in preterm neonates. A simple blood assay for brain natriuretic peptide (BNP) or amino-terminal pro-B-type natriuretic peptide (NT-proBNP) may be useful in the diagnosis and management of hsPDA. Our objectives were to determine the diagnostic accuracy of BNP and NT-proBNP for hsPDA in preterm neonates and to explore heterogeneity by analyzing subgroups.

METHODS

The systematic review was performed as recommended by the Cochrane Diagnostic Test Accuracy Working Group. Electronic databases, conference abstracts, and cross-references were searched. We included studies that evaluated BNP or NT-proBNP (index test) in preterm neonates with suspected hsPDA (participants) in comparison with echocardiogram (reference standard). A bivariate random effects model was used for meta-analysis, and summary receiver operating characteristic curves were generated.

RESULTS

Ten BNP and 11 NT-proBNP studies were included. Studies varied by methodological quality, type of commercial assay, thresholds, age at testing, gestational age, and whether the assay was used to initiate medical or surgical therapy. Sensitivity and specificity for BNP at summary point were 88% and 92%, respectively, and for NT-proBNP they were 90% and 84%, respectively.

CONCLUSIONS

The studies evaluating the diagnostic accuracy of BNP and NT-proBNP for hsPDA varied widely by assay characteristics (assay kit and threshold) and patient characteristics (gestational and chronological age); therefore, generalizability between centers is not possible. We recommend that BNP or NT-proBNP assays be locally validated for specific patient population and outcomes, to initiate therapy or follow response to therapy.

Cerebral tissue oxygen saturation is associated with N-terminal probrain natriuretic peptide in preterm infants on their first day of life

AIM

This prospective observational study investigated if N-terminal probrain natriuretic peptide (NT-proBNP), a cardiac biomarker, correlated with cerebral tissue oxygen saturation (crSO2) in preterm infants on their first day of life.

METHODS

Using near infrared spectroscopy (NIRS), crSO2 was measured on the right forehead of preterm infants for 24 h. We also recorded arterial oxygen saturation (SpO2 ) and calculated fractional tissue oxygen extraction (cFTOE) values. At the end of the NIRS measurement, blood was taken to analyse NT-proBNP. Mean values for the 24-h period were calculated for crSO2 , cFTOE, SpO2 and these values were correlated to NT-proBNP. An echocardiography was performed in all infants during the measurement period.

RESULTS

We analysed 35 preterm neonates (33 ± 2 weeks, 1965 ± 523 g). NIRS measurements started at 3 ± 1 h and blood samples were taken at 24 ± 5 h postnatal. Echocardiography showed an open ductus arteriosus in all infants. Mean NT-proBNP was 4978 ± 3566 pg/mL, crSO2 was 76 ± 8%, and cFTOE was 0.20 ± 0.08. NT-proBNP correlated negatively with crSO2 (r = -0.75; p ≤ 0.001) and positively with cFTOE (r = 0.731; p ≤ 0.001).

CONCLUSION

These results emphasise that crSO2 is influenced by cardiac function, in addition to oxygen consumption, arterial oxygen saturation and vascular resistance, and this can be measured by NT-proBNP.

Importance of N-terminal pro-brain natriuretic peptide in monitoring acute rheumatic carditis

PURPOSE

To detect the relationship of N-terminal pro-brain natriuretic peptide levels with clinical and laboratory findings by measuring them at diagnosis, during, and after treatment in children with acute rheumatic carditis.

METHOD

A total of 40 children including 20 acute rheumatic carditis patients aged between 5 and 16 years 20 healthy children as controls were included in the study. Blood was drawn from patients at diagnosis and in the first week, first month and third month after treatment in order to detect pro-brain natriuretic peptide, C-reactive protein levels and erythrocyte sedimentation rates. All patients underwent echocardiography.

RESULTS

The N-terminal pro-brain natriuretic peptide levels of children with acute rheumatic carditis were significantly higher than those of the control group at diagnosis and during treatment (p<0.05). Echocardiographic evaluation of acute rheumatic carditis patients revealed that the left atrium diameter continued to decrease during the study and that the mean left atrium diameters measured at diagnosis and in the first week were statistically higher than the mean left atrium diameters measured in the third month. There was significant correlation between left atrium diameters at diagnosis and in the first month and N-terminal pro-brain natriuretic peptide levels during the same periods in the patient group.

CONCLUSION

Previous studies have used N-terminal pro-brain natriuretic peptide levels as a marker of enlargement of the left atrium, whereas in this study we want to emphasise its role as a marker of inflammation. This increase was significantly correlated with enlargement in the left atrium. N-terminal pro-brain natriuretic peptide levels were found to be a valuable determinant in indicating cardiac inflammation and haemodynamics.

Clinical characteristics and serum N-terminal pro-brain natriuretic peptide as a diagnostic marker of Kawasaki disease in infants younger than 3 months of age

PURPOSE

The incidence of Kawasaki disease (KD) is rare in young infants (less than 3 months of age), who present with only a few symptoms that fulfill the clinical diagnostic criteria. The diagnosis for KD can therefore be delayed, leading to a high risk of cardiac complications. We examined the clinical characteristics and measured the serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) levels of these patients for assessing its value in the early detection of KD.

METHODS

We retrospectively reviewed the data of young infants diagnosed with KD from 2004 to 2012. The control group included 20 hospitalized febrile patients. Laboratory data, including NT-proBNP were obtained for each patient in both groups.

RESULTS

Incomplete KD was observed in 21/24 patients (87.5%). The mean fever duration on admission was 1.36±1.0 days in the KD group. Common symptoms included erythema at the site of Bacille Calmette-Guerin inoculation (70.8%), skin rash (50.0%), changes of oropharyngeal mucosa (29.1%), and cervical lymphadenopathy (20.8%). The mean number of major diagnostic criteria fulfilled was 2.8±1.4. Five KD patients (20.8%) had only one symptom matching these criteria. The incidence of coronary artery complications was 12.5%. The mean serum NT-proBNP level in the acute phase, in the KD and control groups, were 4,159±3,714 pg/mL and 957±902 pg/mL, respectively, which decreased significantly in the convalescent phase.

CONCLUSION

Incomplete KD was observed in 87.5% patients. Serum NT-proBNP might be a valuable biomarker for the early detection of KD in febrile infants aged <3 months.

Thiamine deficiency and cardiac dysfunction in Cambodian infants

OBJECTIVES

To compare blood thiamine concentrations, echocardiography findings, and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in infants with clinically diagnosed beriberi and healthy matched controls, and to evaluate changes after thiamine treatment.

STUDY DESIGN

Sixty-two Cambodian infants (20 cases and 42 controls), aged 2-47 weeks, were enrolled in this prospective study. Echocardiography and phlebotomy were performed at baseline and after thiamine treatment.

RESULTS

Both cases and controls were thiamine-deficient, with median blood thiamine diphosphate (TDP) concentrations of 47.6 and 55.1 nmol/L, respectively (P = .23). All subjects had normal left ventricular ejection fraction. The median NT-proBNP concentration in cases (340 pg/mL [40.1 pmol/L]) was higher than previously reported normal ranges, but not statistically significantly different from that in controls (175 pg/mL [20.7 pmol/L]) (P = .10), and was not correlated with TDP concentration (P = .13). Two cases with the lowest baseline TDP concentrations (24 and 21 nmol/L) had right ventricular enlargement and elevated NT-proBNP levels that improved dramatically by 48 hours after thiamine administration.

CONCLUSION

Only a minority of thiamine-deficient Cambodian infants demonstrate abnormal echocardiography findings. Thiamine deficiency produces echocardiographic evidence of right ventricular dysfunction, but this evidence is not apparent until deficiency is severe. NT-proBNP concentrations are mildly elevated in sick infants with normal echocardiography findings, indicating possible physiological changes not yet associated with echocardiographic abnormalities.

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.

Biomarkers in congenital heart disease: do natriuretic peptides hold the key?

Congenital heart disease is the most common congenital abnormality. The long-term prognosis of these patients has changed significantly over the last half century, thanks to improvements in cardiovascular diagnosis, surgery and postoperative care. However, residual lesions are not uncommon and many of the interventions performed remain palliative rather than reparative, leading to the development of ventricular dysfunction and heart failure. Natriuretic peptides are well-established markers of disease severity and prognosis in patients with heart failure due to noncongenital (acquired) heart disease. However, the role of biomarkers in congenital heart disease is unclear. This review highlights the impact of neurohormonal activation in patients with congenital heart disease, as well as the usefulness of assessing natriuretic peptide levels in specific clinical situations.

N-terminal pro-brain natriuretic peptide as a useful predictor of early surgery in neonates with congenital heart diseases: a prospective observational study

Pediatric studies have found a correlation between the clinical heart failure score and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. However, the clinical usefulness of this marker remains unclear in neonates. At hospitals without pediatric cardiologists, neonatologists or general pediatricians must judge whether surgery is indicated and transfer patients to a specialized hospital in a timely fashion as required. Thus, we tested the hypothesis that increased NT-proBNP levels predict short-term outcomes in neonates with congenital heart diseases (CHDs) and are thus a useful tool for evaluating clinical status and guiding treatment. Subjects were term or near-term newborns (≥36 weeks' gestation) with CHDs confined to left-to-right shunt lesions. Clinical parameters and NT-proBNP levels were measured on the first 7, 14, 21, and 28 days of life (DOL). We divided patients into a surgical (n = 7) and a conservative-treatment group (n = 21), and then compared clinical variables and outcomes between the groups. In the surgical group, NT-proBNP levels had a tendency to increase during the first 14 postnatal days and were significantly greater than in the conservative-treatment group on 7 DOL [median (range), 13,983 pg/mL (4,732-26,524) vs. 1,954 pg/mL (671-10,881); p = 0.0028] and on 14 DOL [29,274 pg/mL (14,006-33,740) vs. 2,050 pg/mL (1,304-9,250); p = 0.0055]. In contrast, NT-proBNP levels tended to decrease sequentially in the conservative-treatment group. The values of additional markers, such as mean NT-proBNP level on 7 and 14 DOLs (M7-14) and NT-proBNP level on 14 DOL minus that on 7 DOL (Δ7-14), were both significantly greater in the surgical group than in the conservative-treatment group. To examine the usability of M7-14 and Δ7-14 when the difference and mean cut-off levels were set at 10,000 and 3,000 pg/mL, respectively, the sensitivity and specificity were both 100 %. In neonates who had CHDs with left-to-right shunt, analysis of the association between clinical variables and short-term outcomes showed that NT-proBNP, especially M7-14 and Δ7-14, is a useful predictor of early surgery.

The efficacy of cardiac findings in assessing the outcome in preterms with bronchopulmonary dysplasia

OBJECTIVES

To evaluate if cardiac dysfunctions are important in assessing the outcome in newborns with Bronchopulmonary Dysplasia (BPD), by evaluating cardiac functions with N-terminal prohormone of brain natriüretic peptide (NT-proBNP) levels, M-mode and tissue doppler echocardiography at 6-12 mo of age.

METHODS

Twenty eight patients were retrospectively classified as mild, moderate and severe according to the diagnostic criterias for BPD. All cases were assessed with standard M-mode, tissue doppler echocardiography and NT-proBNP levels. Control group consisted of 28 healthy infants, having similar postnatal ages as patients and were assessed with standard M-mode and tissue doppler echocardiography.

RESULTS

The age of patients with BPD was 9.8 ± 2.3 mo and control group was 9.5 ± 2.6 mo. There was no significant difference between the postnatal ages of two groups (p > 0.05). Neither pulmonary hypertension nor pulmonary/tricuspid regurgitation was detected. The M-mode echocardiography measurements did not differ between patients and control group (p > 0.05). Tissue doppler echocardiography, tricuspid valve medial segment early diastolic myocardial relaxation velocity (TME') measurements of patients were found significantly lower, peak transtricuspid filling velocity in the early diastole (TE)/TME' ratios and isovolumetric relaxation time (IVRT) measurements were found significantly higher than control group (p < 0.05). Tricuspid E, TE/TLE' (Tricuspid valve lateral segment early diastolic myocardial relaxation velocity), TE/RVLE'(Right ventricular lateral segment early diastolic myocardial relaxation velocity), TE/TME' levels were also found as significantly abnormal in patients with severe BPD. A significant correlation was found between right ventricular diastolic disfunctions and severity of BPD (p < 0.05). No statistically significant difference was found between NT-proBNP levels, BPD stages and tissue doppler echocardiography measurements (p > 0.05).

CONCLUSIONS

This is the first study evaluating cardiac findings in patients with BPD by tissue doppler echocardiography and NT-proBNP at the same time. On the basis of cardiac evaluations, tissue doppler echocardiography measurements were found as significant and specific for the early assessment of right ventricular diastolic disfunctions.

Evaluation by N-terminal prohormone of brain natriuretic peptide concentrations and ross scoring of the efficacy of digoxin in the treatment of heart failure secondary to congenital heart disease with left-to-right shunts

This study aimed to evaluate the effectiveness of digoxin in children with heart failure secondary to left-to-right shunt lesions and normal left ventricular systolic function. The study registered 37 such patients (ages 10 days to 24 months, groups 1 and 2) and used 20 healthy children as a control group (group 3). Left ventricular systolic function, as assessed by conventional echocardiography, was normal in all the subjects. Congestive heart failure was diagnosed by clinical evaluation and modified Ross scoring. Plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations and complete blood counts were assessed in all the children. Group 1 was treated with digoxin, enalapril, and furosemide and group 2 with enalapril and furosemide. Approximately 1 month after starting treatment, the patients were reevaluated by physical and echocardiographic examinations, modified Ross scoring, plasma NT-proBNP concentrations, and complete blood counts. The pre- and posttreatment Ross scores of group 1 (p = 0.377) and group 2 (p = 0.616) did not differ significantly. The NT-proBNP values in both groups decreased after treatment (p = 0.0001). The pre- and posttreatment NT-proBNP values did not differ significantly in group 1 (p = 0.094)) and group 2 (p = 0.372). The pretreatment NT-proBNP values in groups 1 and 2 (p = 0.0001) were significantly higher than in the control group (p = 0.003). A smaller difference was observed between posttreatment NT-proBNP values in group 1 and the control group (p = 0.045). We found no significant difference between the posttreatment NT-proBNP values of group 2 and those of the control group (p = 0.271). The study showed that both treatments currently used to treat heart failure secondary to congenital heart disease with left-to-right shunts and preserved left ventricular systolic function are effective and do not differ significantly. Thus, digoxin does not provide any extra benefit in the treatment of such patients.

Aminoterminal pro-B-type natriuretic peptide: heart or lung disease in the neonate?

OBJECTIVES

B-type natriuretic peptides have been shown to enable differentiation between heart and lung diseases in adults and children. In neonates, the role of natriuretic peptides for diagnosis of congenital heart defect (CHD) is not yet ascertained. The purpose of this single-center prospective study was to investigate aminoterminal B-type natriuretic peptide concentrations and their time courses during the first 5 days of life in neonates with CHD compared with neonates with respiratory distress.

DESIGN

Single-center prospective study.

SETTING

Tertiary-care neonatal ICU.

PATIENTS

Aminoterminal B-type natriuretic peptide levels of 40 neonates with arterial duct-dependent CHD and of 40 neonates with respiratory distress without CHD were analyzed on the first, second, third, and fifth day of life.

MAIN RESULTS

Mean aminoterminal B-type natriuretic peptide concentrations in the CHD group were significantly higher on the second (14191 vs. 4872 pg/mL), third (17790 vs. 3524 pg/mL), and fifth day (17015 vs. 4044 pg/mL), but not on the first day of life. Repeated measurements analysis of variance revealed a significantly different time course of aminoterminal B-type natriuretic peptide concentrations between the two groups.

CONCLUSIONS

On the first day of life, aminoterminal B-type natriuretic peptide cannot differentiate between CHD and respiratory distress without CHD in the neonate. From the second day onwards, aminoterminal B-type natriuretic peptide in neonates with CHD shows higher values and a different time course and enables differentiation between CHD and respiratory distress due to other than cardiac reasons.

Use of cardiac biomarkers in neonatology

Cardiac biomarkers are used to identify cardiac disease in term and preterm infants. This review discusses the roles of natriuretic peptides and cardiac troponins. Natriuretic peptide levels are elevated during atrial strain (atrial natriuretic peptide (ANP)) or ventricular strain (B-type natriuretic peptide (BNP)). These markers correspond well with cardiac function and can be used to identify cardiac disease. Cardiac troponins are used to assess cardiomyocyte compromise. Affected cardiomyocytes release troponin into the bloodstream, resulting in elevated levels of cardiac troponin. Cardiac biomarkers are being increasingly incorporated into clinical trials as indicators of myocardial strain. Furthermore, cardiac biomarkers can possibly be used to guide therapy and improve outcome. Natriuretic peptides and cardiac troponins are potential tools in the diagnosis and treatment of neonatal disease that is complicated by circulatory compromise. However, clear reference ranges need to be set and validation needs to be carried out in a population of interest.

The role of plasma N-terminal pro-B-type natriuretic peptide in predicting the severity of transient tachypnea of the newborn

BACKGROUND/AIM

Transient tachypnea of the newborn (TTN) is a consequence of inadequate neonatal lung fluid clearance. Natriuretic peptides play an important role in the regulation of extracellular fluid volume. The aim of the study was to investigate the relation between plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and TTN, and to find out its role in predicting disease severity.

METHODS

A prospective controlled study involving 67 infants with TTN and 33 controls ≥34 weeks gestational age was conducted. Study and control groups were compared for plasma NT-proBNP levels measured on the 6th, 24th, 72nd and 120th hours of life. Cardiac systolic functions were evaluated by echocardiography.

RESULTS

NT-proBNP levels were significantly higher in neonates with TTN compared to controls at 6th, 24th, 72nd and 120th hours (p<0.001). NT-proBNP levels at 24th and 72nd hours were significantly higher in infants with prolonged tachypnea (p=0.007 and p=0.03) and in those who required respiratory support (p=0.006 and p<0.001). Tachypnea duration was correlated with NT-proBNP levels at 24h (r=0.41, p=0.001). At a cut-off value of 6575 pg/ml, NT-proBNP had a sensitivity of 85% and specificity of 64% to predict mechanical ventilation requirement. Cardiac systolic functions were normal in all TTN patients.

CONCLUSION

Plasma NT-proBNP levels are increased in neonates with TTN. Measurement of plasma NT-proBNP can be useful for predicting infants who will have prolonged tachypnea and mechanical ventilation requirement.

B-type natriuretic peptides are reliable markers of cardiac strain in CKD pediatric patients

Myocardial damage and strain are common in children with chronic renal failure. The most prevalent pathologies, as defined by echocardiography, are left ventricular hypertrophy (LVH), diastolic and systolic dysfunction, and altered LV geometry. Troponin I and T, as well as B-type natriuretic peptide (BNP) and its cleavage fragment NT-proBNP, are known to be good markers of myocardial damage and stress, respectively, in the general adult population and among those with chronic kidney disease (CKD). In this study we measured the levels of troponins I and T, BNP, and NT-proBNP in a group of children and young adults with CKD stages 3-5 and determined their respective correlations with echocardiographic and laboratory abnormalities. BNP and NT-proBNP levels and their log values correlated well with the following parameters: diastolic blood pressure, estimated glomerular filtration rate, time-averaged hemoglobin levels, and LV mass. Both BNP and NT-proBNP levels, but not those of either troponin, were found to be reliable surrogate markers of strained hearts, defined as having LVH or diastolic or systolic dysfunction, in the pediatric CKD stages 3-4 group. The log NT-proBNP value was also found to be a good marker of cardiac strain in the CKD stage 5 group of patients. Serum BNP and NT-proBNP threshold concentrations of 43 and 529 pg/ml, respectively, were found to have the best sensitivity and specificity in predicting strained hearts. Based on these findings, we conclude that both BNP and NT-proBNP levels, but not those of troponins I and T, can serve as inexpensive, simple, and reliable markers of stressed hearts in the pediatric CKD patient population.

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.

Urinary N-terminal B-type natriuretic peptide predicts severe retinopathy of prematurity

OBJECTIVE

The goal of this study was to evaluate urinary N-terminal fragment of B-type natriuretic peptide concentrations, normalized to creatinine (UNBCR), to predict morbidities at discharge in preterm infants.

METHODS

UNBCR were determined in urine collected on day of life (DOL) 2, 7, 14, and 28 in 136 preterm infants <1500 g birth weight, 22 of whom developed bronchopulmonary dysplasia (BPD), defined as oxygen supplementation at 36 weeks' gestational age) and 11 infants developed severe retinopathy (ROP), defined as stage 3 or stage ≥ 2 requiring surgery).

RESULTS

UNBCR on DOL 7, 14, and 28 was elevated in infants who developed BPD or ROP compared with controls (P ≤ .001). On multiple regression analysis including birth weight and gestational age, ROP but not BPD remained independently associated with UNBCR on DOL 14 and 28. Areas under receiver operating characteristic curves for UNBCR on DOL 14 and 28 to predict ROP were 0.938 (0.027) and 0.954 (0.021), respectively. UNBCR DOL 14 and 28 thresholds exceeded by all infants with severe ROP (100% sensitivity, 100% negative predictive value) had a specificity of 66% and 85%, respectively.

CONCLUSIONS

UNBCR might hold promise to reduce unnecessary eye examinations by timely and accurate identification of infants at risk of severe ROP.

Impaired cardiac reserve and severely diminished skeletal muscle O₂ utilization mediate exercise intolerance in Barth syndrome

Barth syndrome (BTHS) is a mitochondrial myopathy characterized by reports of exercise intolerance. We sought to determine if 1) BTHS leads to abnormalities of skeletal muscle O(2) extraction/utilization and 2) exercise intolerance in BTHS is related to impaired O(2) extraction/utilization, impaired cardiac function, or both. Participants with BTHS (age: 17 ± 5 yr, n = 15) and control participants (age: 13 ± 4 yr, n = 9) underwent graded exercise testing on a cycle ergometer with continuous ECG and metabolic measurements. Echocardiography was performed at rest and at peak exercise. Near-infrared spectroscopy of the vastus lateralis muscle was continuously recorded for measurements of skeletal muscle O(2) extraction. Adjusting for age, peak O(2) consumption (16.5 ± 4.0 vs. 39.5 ± 12.3 ml·kg(-1)·min(-1), P < 0.001) and peak work rate (58 ± 19 vs. 166 ± 60 W, P < 0.001) were significantly lower in BTHS than control participants. The percent increase from rest to peak exercise in ejection fraction (BTHS: 3 ± 10 vs. control: 19 ± 4%, P < 0.01) was blunted in BTHS compared with control participants. The muscle tissue O(2) saturation change from rest to peak exercise was paradoxically opposite (BTHS: 8 ± 16 vs. control: -5 ± 9, P < 0.01), and the deoxyhemoglobin change was blunted (BTHS: 0 ± 12 vs. control: 10 ± 8, P < 0.09) in BTHS compared with control participants, indicating impaired skeletal muscle extraction in BTHS. In conclusion, severe exercise intolerance in BTHS is due to both cardiac and skeletal muscle impairments that are consistent with cardiac and skeletal mitochondrial myopathy. These findings provide further insight to the pathophysiology of BTHS.

Current applications and Future Needs for Biomarkers in Pediatric Cardiomyopathy and Heart Failure: Summary From The Second International Conference On Pediatric Cardiomyopathy

Biomarkers have established an important role in the diagnosis and prognosis of heart failure in adults, with early indications being that their sensitivity and specificity will be similar in the pediatric population. Since early detection of remodeling is vital to preemptive management in cardiomyopathy and in heart disease arising from congenital lesions, biomarkers may offer a means of identifying high risk patients before they develop symptoms. Although in current use, natriuretic peptides high sensitivity troponins, and C-reactive protein need to have their applications more clearly defined in pediatrics, by evidence based guidelines. Exploratory work should meanwhile continue to define the risk of disease progression in patients with dilated cardiomyopathy, and of sudden death in hypertrophic cardiomyopathy based on biomarker profiles. Further research into the interaction of the genetic basis of disease and proteomic biomarkers will be a valuable means of assessing the importance of different pathways of disease related ventricular remodeling.

The evolving approach to paediatric myocarditis: a review of the current literature

Paediatric myocarditis remains challenging from the perspectives of diagnosis and management. Multiple aetiologies exist and the majority of cases appear to be related to viral illnesses. Enteroviruses are believed to be the most common cause, although cases related to adenovirus may be more frequent than suspected. The clinical presentation is extremely varied, ranging from asymptomatic to sudden unexpected death. A high index of suspicion is crucial. There is emerging evidence to support investigations such as serum N-terminal B-type natriuretic peptide levels, as well as cardiac magnetic resonance imaging as adjuncts to the clinical diagnosis. In the future, these may reduce the necessity for invasive methods, such as endomyocardial biopsy, which remain the gold standard. Management generally includes supportive care, consisting of cardiac failure medical management, with the potential for mechanical support and cardiac transplantation. Treatments aimed at immunosuppression remain controversial. The paediatric literature is extremely limited with no conclusive evidence to support or refute these strategies. This article summarises the current literature regarding aetiology, clinical presentation, diagnosis, and management of myocarditis in paediatric patients.

Serum Levels of Natriuretic Peptides in Children before and after Treatment for an Atrial Septal Defect, a Patent Ductus Arteriosus, and a Coarctation of the Aorta-A Prospective Study

Background and Objectives. We evaluated and compared the influence of treatment for atrial septal defect (ASD), patent ductus arteriosus (PDA), and coarctation of the aorta (CoA) on serum levels of N-terminal proatriopeptide and N-terminal probrain natriuretic peptide. Correlations between peptide levels and echocardiographic measurements were calculated. Patients and Methods. Peptide levels were measured and echocardiography performed before and 6-12 months after treatment in 21 children with ASD, 25 with PDA, 15 with CoA, and 76 control children. Results. ANPN levels were higher than in controls at baseline in all patient groups, and NT-proBNP in patients with ASD and PDA. Both peptide levels were elevated 6 months after treatment and decreased thereafter. Peptide levels were higher in patients with volume than pressure overload. They correlated with echocardiographic measurements. At the 6-month follow-up, dimensions of the originally overloaded ventricle had normalized only in patients with PDA. Conclusions. After intervention, peptide levels decrease but normalization takes over 6 months. The type of correlation between peptide levels and echocardiography varies according to the loading condition. Measurement of peptide levels can be used for monitoring the course of a patient's heart disease.

Clinical and functional characterisation of rheumatic mitral regurgitation in children and adolescents including the brain natriuretic peptide

Rheumatic fever is a public health problem of universal distribution, predominantly affecting individuals in developing countries. In individuals less than 20 years of age, pure mitral regurgitation is the most commonly found condition in chronic rheumatic valve disease. In the present study, rheumatic mitral regurgitation was assessed in children and adolescents, addressing its clinical (duration of the disease, symptoms, use of benzathine penicillin, and number of outbreaks of the acute phase of rheumatic fever), electrocardiographic (left atrium abnormality and/or left ventricle hypertrophy) and echocardiographic characteristics (left atrium and ventricle measurements, ejection fraction and pulmonary artery pressure), as well as plasma dose of N-terminal portion of the brain natriuretic peptide through electrochemiluminescence immunoassay. Fifty-three patients were studied. The patients had moderate (41.5%) or severe (58.5%) rheumatic mitral regurgitation; had not undergone surgery; were not in the acute phase of the disease; and were being treated at a paediatric cardiology reference hospital in Northeastern Brazil. Mean patient age was 10.6 years (minimum of 3 and maximum of 19 years). With the exception of the ejection fraction, the echocardiographic variables had a significant correlation to the natriuretic peptide, demonstrating that this hormone reflects the haemodynamic consequences of mitral regurgitation. It was concluded that cardiac remodelling that occurs in rheumatic mitral regurgitation in children and adolescents leads to the production of the brain natriuretic peptide, which could be used as a complementary diagnostic tool in the follow-up of such patients.

The Use of N-Terminal-Pro-BNP in Preterm Infants

The use of natriuretic peptides in the neonatal population is emerging. B-type Natriuretic Peptide (BNP) and N-terminal-Pro-BNP (NTpBNP) are used in the adult population to assess myocardial function and volume loading. Their role in prognosis following cardiac surgery has also been identified. In preterm infants NTpBNP is becoming increasingly recognised as a potential screening tool for patent ductus arteriosus (PDA), and a marker for myocardial performance. In addition, NTpBNP may provide prognostic information in preterm infants and term infants with congenital diaphragmatic hernia (CDH). In this paper, the role of NTpBNP in the preterm population will be discussed.