B-type natriuretic peptide: prognostic marker in congenital diaphragmatic hernia

Congenital Diaphragmatic Hernia: Pulmonary Hypertension and Pulmonary Vascular Disease

This review provides a comprehensive summary of the current understanding of pulmonary hypertension (PH) in congenital diaphragmatic hernia, outlining the underlying pathophysiologic mechanisms, methods for assessing PH severity, optimal management strategies, and prognostic implications.

Prognostic value of echocardiographic parameters in congenital diaphragmatic hernia: a systematic review and meta-analysis

BACKGROUND

Prognostication of mortality and decision to offer extracorporeal membrane oxygenation (ECMO) treatment in infants with congenital diaphragmatic hernia (CDH) can inform clinical management.

OBJECTIVE

To summarise the prognostic value of echocardiography in infants with CDH.

METHODS

Electronic databases Ovid MEDLINE, Embase, Scopus, CINAHL, the Cochrane Library and conference proceedings up to July 2022 were searched. Studies evaluating the prognostic performance of echocardiographic parameters in newborn infants were included. Risk of bias and applicability were assessed using the Quality Assessment of Prognostic Studies tool. We used a random-effect model for meta-analysis to compute mean differences (MDs) for continuous outcomes and relative risk (RR) for binary outcomes with 95% CIs. Our primary outcome was mortality; secondary outcomes were need for ECMO, duration of ventilation, length of stay, and need for oxygen and/or inhaled nitric oxide.

RESULTS

Twenty-six studies were included that were of acceptable methodological quality. Increased diameters of the right and left pulmonary arteries at birth (mm), MD 0.95 (95% CI 0.45 and 1.46) and MD 0.79 (95% CI 0.58 to 0.99), respectively) were associated with survival. Left ventricular (LV) dysfunction, RR 2.40, (95% CI 1.98 to 2.91), right ventricular (RV) dysfunction, RR 1.83 (95% CI 1.29 to 2.60) and severe pulmonary hypertension (PH), RR 1.69, (95% CI 1.53 to 1.86) were associated with mortality. Left and RV dysfunctions, RR 3.30 (95% CI 2.19 to 4.98) and RR 2.16 (95% CI 1.85 to 2.52), respectively, significantly predicted decision to offer ECMO treatment. Limitations are lack of consensus on what parameter is optimal and standardisation of echo assessments.

CONCLUSIONS

LV and RV dysfunctions, PH and pulmonary artery diameter are useful prognostic factors among patients with CDH.

CA125: a novel cardiac biomarker for infants with congenital diaphragmatic hernia

BACKGROUND

The carbohydrate antigen 125 (CA125) was proven as a robust biomarker for risk stratification in adults with heart failure. This is the first study analyzing CA125 in a cohort of infants with congenital diaphragmatic hernia (CDH).

METHODS

Sixty-eight infants with CDH, treated at the University Children's Hospital Bonn (Germany), between January 2018 and February 2021, were prospectively enrolled for analysis. CA125 values were measured at the following timepoints: 6,12, 24, 48 h, and during ECMO daily from day 1 to day 7.

RESULTS

In infants not surviving to discharge, CA125 values were significantly higher at day 1 (6, 12, and 24 h). Infants with subsequent need for ECMO presented significantly higher CA125 values at 12 h of life. During ECMO, CA125 values measured at day 1 were significantly higher in infants not surviving to discharge. In the ROC analysis, a CA125 value of ≥10 U/ml was calculated as optimal cut-off for the prediction of ECMO and in-hospital mortality. CA125 values correlated significantly with the severity of PH and ventricular dysfunction.

CONCLUSIONS

CA125 values correlate significantly with echocardiographic markers of PH and ventricular dysfunction and correlate significantly with parameters of disease severity (need for ECMO, mortality).

IMPACT

CA125 was proven as robust cardiac biomarker in adult cohorts. Information about the utility as a biomarker in neonatal cohorts is lacking. This is the first study analyzing CA125 as a cardiac biomarker in a cohort of infants with congenital diaphragmatic hernia (CDH). CA125 correlates significantly with markers of echocardiographic assessment (PH and ventricular dysfunction) in infants with CDH and helps to identify infants at high risk for ECMO and in-hospital mortality. The results underline the need for the inclusion of cardiac biomarkers in the clinical routine in neonates at risk for cardiopulmonary failure.

Neonatal intensive care unit on-site surgery for congenital diaphragmatic hernia

The present study presents the experience gained in the Newborn Intensive Care Unit (NICU) of 'Maria S. Curie' Emergency Clinical Hospital for Children in Bucharest (Romania) after performing a series of bedside surgery interventions on newborns with congenital diaphragmatic hernia (CDH). We conducted a retrospective analysis of the data for all patients operated on-site between 2011 and 2020, in terms of pre- and post-operative stability, procedures performed, complications and outcomes. An analysis of a control group was used to provide a reference to the survival rate for non-operated patients. The present study is based on data from 10 cases of newborns, surgically operated on, on average, on the fifth day of life. The main reasons for operating on-site included hemodynamical instability and the need to administer inhaled nitric oxide (iNO) and high-frequency oscillatory ventilation (HFOV). There were no unforeseen events during surgery, no immediate postoperative complications and no surgery-related mortality. One noticed drawback was the unfamiliarity of the surgery team with the new operating environment. Our experience indicates that bedside surgery improves the likelihood of survival for critically ill neonates suffering from CDH. No immediate complications were associated with this practice.

Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare birth defect characterized by incomplete closure of the diaphragm and herniation of fetal abdominal organs into the chest that results in pulmonary hypoplasia, postnatal pulmonary hypertension owing to vascular remodelling and cardiac dysfunction. The high mortality and morbidity rates associated with CDH are directly related to the severity of cardiopulmonary pathophysiology. Although the aetiology remains unknown, CDH has a polygenic origin in approximately one-third of cases. CDH is typically diagnosed with antenatal ultrasonography, which also aids in risk stratification, alongside fetal MRI and echocardiography. At specialized centres, prenatal management includes fetal endoscopic tracheal occlusion, which is a surgical intervention aimed at promoting lung growth in utero. Postnatal management focuses on cardiopulmonary stabilization and, in severe cases, can involve extracorporeal life support. Clinical practice guidelines continue to evolve owing to the rapidly changing landscape of therapeutic options, which include pulmonary hypertension management, ventilation strategies and surgical approaches. Survivors often have long-term, multisystem morbidities, including pulmonary dysfunction, gastroesophageal reflux, musculoskeletal deformities and neurodevelopmental impairment. Emerging research focuses on small RNA species as biomarkers of severity and regenerative medicine approaches to improve fetal lung development.

Early diagnosis and targeted approaches to pulmonary vascular disease in bronchopulmonary dysplasia

Pulmonary hypertension has emerged as a life-threatening disease in preterm infants suffering from bronchopulmonary dysplasia (BPD). Its development is closely linked to respiratory disease, as vasculogenesis and alveologenesis are closely interconnected. Once clinically significant, BPD-associated pulmonary hypertension (BPD-PH) can be challenging to manage, due to poor reversibility and multiple comorbidities frequently associated. The pulmonary vascular disease process underlying BPD-PH is the result of multiple innate and acquired factors, and emerging evidence suggests that it progressively develops since birth and, in certain instances, may begin as early as fetal life. Therefore, early recognition and intervention are of great importance in order to improve long-term outcomes. Based on the most recent knowledge of BPD-PH pathophysiology, we review state-of-the-art screening and diagnostic imaging techniques currently available, their utility for clinicians, and their applicability and limitations in this specific population. We also discuss some biochemical markers studied in humans as a possible complement to imaging for the detection of pulmonary vascular disease at its early stages and the monitoring of its progression. In the second part, we review pharmacological agents currently available for BPD-PH treatment or under preclinical investigation, and discuss their applicability, as well as possible approaches for early-stage interventions in fetuses and neonates. IMPACT: BPD-associated PH is a complex disease involving genetic and epigenetic factors, as well as environmental exposures starting from fetal life. The value of combining multiple imaging and biochemical biomarkers is emerging, but requires larger, multicenter studies for validation and diffusion. Since "single-bullet" approaches have proven elusive so far, combined pharmacological regimen and cell-based therapies may represent important avenues for research leading to future cure and prevention.

Increased N-terminal Pro-B-Type Natriuretic Peptide during Extracorporeal Life Support Is Associated with Poor Outcome in Neonates with Congenital Diaphragmatic Hernia

OBJECTIVES

To evaluate the prognostic information derived from the daily measurements of N-terminal pro-B-type natriuretic peptide (proBNP) in neonates with congenital diaphragmatic hernia undergoing extracorporeal life support (ECLS).

STUDY DESIGN

Plasma proBNP was prospectively measured daily during the first week of ECLS using an electrochemiluminescence immunoassay. Patients (n = 63) were allocated according to outcome: survivors (group 1, n = 35); nonsurvivors with successful weaning (defined as survival for >12 hours after ECLS discontinuation) (group 2, n = 16); nonsurvivors with unsuccessful weaning (group 3, n = 12). ProBNP kinetics were compared using Kruskal-Wallis testing and correlated with pulmonary hypertension and cardiac dysfunction on echocardiography using the Spearman correlation coefficient.

RESULTS

Infants in group 3 presented significantly higher proBNP values from day 3 to day 6 compared with group 1 and 2. Overall mortality among patients with the highest proBNP values on day 1 was 30.6% compared with 63% in those patients with at least 1 higher value on day 2 to day 7. In patients with a late increase (day 4 to day 7) in proBNP the mortality was 70%, compared with 32.6% in those with proBNP below the value on day 1. Weaning failure was 35% in patients with a late increase and 11.6% in those without a late increase. ProBNP correlated significantly with pulmonary hypertension and cardiac dysfunction before and during ECLS.

CONCLUSIONS

Absolute proBNP values are associated with weaning failure but not overall mortality in neonates with congenital diaphragmatic hernia undergoing ECLS. Echocardiographic findings correlate well with proBNP values.

Application of B-Type Natriuretic Peptide in Neonatal Diseases

Numerous congenital or secondary diseases, including, heart disease, respiratory disease, sepsis and many others, can lead to neonatal death. B-type natriuretic peptide (BNP) is a peptide hormone secreted by ventricular cells following an increase in ventricular wall tension. BNP functions to promote vasodilation, diuresis, and sodium release to regulate blood pressure. BNP is a sensitive index reflecting ventricular function, which may aid the diagnosis and monitoring of various neonatal diseases. In neonates, there is currently no consensus on a reference BNP level, as the plasma BNP concentration of healthy newborns varies with age, peaks in the first week after birth, and then gradually decreased to a stable level. In disease states, the correlation between the plasma BNP concentration and the results of echocardiography is good, which is of great significance in the screening, monitoring, and prognosis evaluation of neonatal cardiovascular diseases, including congenital heart disease, patent ductus arteriosus, etcetera. It also facilitates the judgment of the efficacy of treatment and perioperative management. Moreover, the monitoring of plasma BNP concentration provides guidance for the diagnosis, evaluation, and treatment selection of certain neonatal respiratory diseases and neonatal sepsis. This review summarizes the normal BNP values and discusses the application value of BNP in relation to physiological and pathological aspects in neonates.

Longitudinal B-Type Natriuretic Peptide Levels Predict Outcome in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate B-type natriuretic peptide (BNP) as a longitudinal biomarker of clinical outcome in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a retrospective study of 49 infants with CDH, classifying the cohort by respiratory status at 56 days, based on a proposed definition of bronchopulmonary dysplasia for infants ≥32 weeks' gestation: good outcome (alive with no respiratory support) and poor outcome (ongoing respiratory support or death). BNP levels were available at age 1-5 weeks. Longitudinal BNP trends were assessed using mixed-effects modeling. Receiver operating characteristic curves were generated to identify BNP cutoffs maximizing correct outcome classification at each time point. The time to reach BNP cutoff by outcome was assessed using Kaplan-Meier curves for weeks 3-5.

RESULTS

Twenty-nine infants (59%) had a poor outcome. Infants with a poor outcome were more likely than those with a good outcome to have liver herniated into the thorax (90% vs 50%; P = .002) and to undergo nonprimary repair (93% vs 35%; P < .001). Mixed-effects modeling demonstrated a differing decline in BNP over time by outcome group (P = .003 for interaction). BNP accurately predicted outcome at 3-5 weeks (area under the curve, 0.81-0.82). BNP cutoffs that maximized correct outcome classification decreased over time from 285 pg/mL at 3 weeks to 100 pg/mL at 4 weeks and 48 pg/mL at 5 weeks. Time to reach the cutoffs of 100 pg/mL and 48 pg/mL were longer in the poor outcome group (log-rank P = .006 and <.0001, respectively).

CONCLUSIONS

Elevated BNP accurately predicts poor outcome in infants with CDH at age 3-5 weeks, with declining cutoffs over 3-5 weeks of age.

Early postnatal changes of circulating N-terminal-pro-B-type natriuretic peptide in neonates with congenital diaphragmatic hernia

BACKGROUND

Severity of lung hypoplasia, pulmonary hypertension (PH) and cardiac dysfunction are major contributors to mortality in congenital diaphragmatic hernia (CDH). Therefore, early assessment and management is important to improve outcome. NT-proBNP is an established cardiac biomarker with only limited data for early postnatal risk assessment in CDH newborns.

AIMS

To investigate the correlation of NT-proBNP at birth, 6 h, 12 h, 24 h, and 48 h with PH and cardiac dysfunction and the prognostic information of NT-proBNP for the use of ECMO support or mortality.

SUBJECTS

44 CDH newborns treated at our institution (December 2014-October 2017) were prospectively enrolled.

OUTCOME MEASURES

Primary clinical endpoint was either need for ECMO or death within the first 48 h (group A). Infants not receiving ECMO support were allocated to group B. Mortality was tested as secondary endpoint.

RESULTS

NT-proBNP levels measured at 6 h, 12 h, 24 h and 48 h postpartum correlated significantly with PH severity following NICU admission and at 24 h, and with severity of cardiac dysfunction at birth, 24 h, 48 h and after 7 days of life. There was no difference in NT-proBNP levels between survivors and non-survivors. NT-proBNP levels were significantly higher in group A at 6 h (p = 0.007), 12 h (p = 0.036), and 24 h (p = 0.007), but not at birth (p = 0.785) or 48 h (p = 0.15) compared to group B.

CONCLUSION

NT-proBNP analysis in the first 48 h of life may be useful to assess PH and cardiac dysfunction in CDH newborns and to predict the need for ECMO support.

Congenital diaphragmatic hernia-associated pulmonary hypertension

Congenital diaphragmatic hernia (CDH) is a neonatal pathology in which intrathoracic herniation of abdominal viscera via diaphragmatic defect results in aberrant pulmonary and cardiovascular development. Despite decades of study and many advances in the diagnosis and treatment of CDH, morbidity and mortality remain high, largely due to pulmonary hypertension (PH), along with pulmonary hypoplasia and cardiac dysfunction. In patients with CDH, hypoplastic pulmonary vasculature and alterations in multiple molecular pathways lead to pathophysiologic pulmonary vasculopathy and, for severe CDH, sustained, elevated pulmonary arterial pressures. This review addresses the multiple anatomic and physiologic changes that underlie CDH-associated PH (CDH-PH), along with the multimodal treatment strategies that exist currently and future therapies currently under investigation.

Detection platforms for point-of-care testing based on colorimetric, luminescent and magnetic assays: A review

Along with the considerable potential and increasing demand of the point-of-care testing (POCT), corresponding detection platforms have attracted great interest in both academic and practical fields. The first few generations of conventional detection devices tend to be costly, complicated to operate and hard to move on account of early limitations in the level of technological development and relatively high requirement of performance. Owing to the requirements for rapidity, simplicity, accuracy and cost controlling in the POCT, reader systems are urgently needed to be developed, upgraded and modified constantly, realizing on-site testing and healthcare management without a specific place or cumbersome operation. Accordingly, numerous rapid detection platforms with diverse size and performance have emerged such as bench-top apparatuses, handheld devices and intelligent detection devices. This review discusses various devices developed mainly for the detection of lateral flow test strips (LFTSs) or microfluidic strips in the POCT and summarizes these devices by size and portability. Furthermore, on the basis of various detection methods and diverse probes usually containing specific nanoparticles composites, three most common aspects of detection rationale in the POCT are selected to elaborate each kind of detection platforms in this paper: colorimetric assay, luminescent detection and magnetic signal detection. Herein, we focus on their structures, detection mechanisms and assay results, accompany with discussions and comments on the performances, costs and potential application, as well as advantages and limitations of each technique. In addition, perspectives on the future advances of detection platforms and some conclusions are proposed.

Use of prostaglandin E1 to treat pulmonary hypertension in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE.

METHODS

We performed a retrospective chart review of CDH infants treated at our center between 2011 and 2016. In a subset, PGE was initiated for echocardiographic evidence of severe PH, metabolic acidosis, or hypoxemia. To assess PH response, we evaluated laboratory data, including B-type natriuretic peptide (BNP) and echocardiograms before and after PGE treatment. Categorical and continuous data were analyzed with Fisher's exact tests and Mann-Whitney t-tests, respectively.

RESULTS

Fifty-seven infants were treated with PGE a mean 17 ± 2 days. BNP levels declined after 1.4 ± 0.2 days of treatment and again after 5.2 ± 0.6 days. After 6 ± 0.8 days of treatment, echocardiographic estimates of severe PH by tricuspid regurgitation jet velocity, ductus arteriosus direction, and ventricular septum position also improved significantly. Treatment was not associated with postductal hypoxemia or systemic hypoperfusion.

CONCLUSIONS

In patients with CDH and severe PH, PGE is well tolerated and associated with improved BNP and echocardiographic indices of PH, suggesting successful unloading of the RV.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

N-Terminal Pro-B-Type Natriuretic Peptide as a Biomarker of Bronchopulmonary Dysplasia or Death in Preterm Infants: A Retrospective Cohort Analysis

Objectives: To investigate the association between serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) level on the first day of life and a composite outcome of bronchopulmonary dysplasia (BPD) or death in a cohort of infants born before 32 weeks of gestation. Methods: We retrospectively identified infants born before 32 weeks of gestation who had serum NT-proBNP levels measured when they were admitted to the Neonatal Intensive Care Unit shortly after birth. The outcome of BPD or death was assessed at 36 weeks of postmenstrual age. The association of serum NT-proBNP levels with BPD or death was evaluated. Receiver operator characteristic (ROC) curve analysis was used to evaluate the predictive performance of serum NT-proBNP levels. Results: A 100 and 47 preterm infants had serum NT-proBNP levels measured on the first day of life. Serum NT-proBNP level was significantly higher in preterm infants who developed moderate/severe BPD or died [3,855 (2,567-6,369) vs. 1,259 (950-2,035) in control infants, P < 0.001]. On binary regression analysis, a high natural logarithm of serum NT-proBNP levels was associated with increased risk of moderate/severe BPD or death adjusted for gestational age, birth weight, birth weight z-score, and Apgar scores at 1 and 5 min (odds ratio [OR] = 5.195, 95% confidence interval [CI] 2.667-10.117, P < 0.001). ROC analysis identified a NT-proBNP level of 2002.5 pg/mL to have 87.5% sensitivity and 74.7% specificity for predicting moderate/severe BPD or death. The area under the curve (AUC) was 0.853 (95% CI 0.792-0.914). Conclusion: Serum NT-proBNP level measured on the first day of life is a promising biomarker for predicting the development of moderate/severe BPD or death in preterm infants. Our findings warrant a larger prospective study to incorporate measurement of NT-proBNP in prognosticating outcomes in very preterm infants.

Predicting Risk of Infection in Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

To predict incident bloodstream infection and urinary tract infection (UTI) in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a retrospective analysis using the Children's Hospital Neonatal Database during 2010-2016. Infants with CDH admitted at 22 participating regional neonatal intensive care units were included; patients repaired or discharged to home prior to admission/referral were excluded. The primary outcome was death or the occurrence of bloodstream infection or UTI prior to discharge. Factors associated with this outcome were used to develop a multivariable equation using 80% of the cohort. Validation was performed in the remaining 20% of infants.

RESULTS

Median gestation and postnatal age at referral in this cohort (n = 1085) were 38 weeks and 3.1 hours, respectively. The primary outcome occurred in 395 patients (36%); and was associated with low birth weight, low Apgar, low admission pH, renal and associated anomalies, patch repair, and extracorporeal membrane oxygenation (P < .001 for all; area under receiver operating curve = 0.824; goodness of fit χ² = 0.52). After omitting death from the outcome measure, admission pH, patch repair of CDH, and duration of central line placement were significantly associated with incident bloodstream infection or UTI.

CONCLUSIONS

Infants with CDH are at high risk of infection which was predicted by clinical factors. Early identification and low threshold for sepsis evaluations in high-risk infants may attenuate acquisition and the consequences of these infections.

Treprostinil Improves Persistent Pulmonary Hypertension Associated with Congenital Diaphragmatic Hernia

OBJECTIVE

To evaluate the effect of continuous treprostinil in infants with severe pulmonary hypertension associated with congenital diaphragmatic hernia (CDH) on specific markers of pulmonary hypertension severity and to report the safety and tolerability of treprostinil.

STUDY DESIGN

We conducted a retrospective cohort study of infants with CDH-associated pulmonary hypertension treated with treprostinil from January 2011 to September 2016. Severity of pulmonary hypertension was assessed by echocardiogram and serum B-type natriuretic peptide (BNP) by using time points before initiation and 24 hours, 1 week, and 1 month after treprostinil initiation. Fisher exact tests, Wilcoxon-rank sum tests, and mixed-effects models were used for analysis.

RESULTS

Seventeen patients were treated with treprostinil for a median of 54.5 days (IQR 44.3-110 days). Compared with the concurrent CDH population (n = 147), infants treated with treprostinil were more likely to require extracorporeal support (76.5% vs 25.2%, P < .0001), to have a longer hospital stay (144 vs 60 days, P < .0001), and to need longer mechanical ventilator support (76.5 vs 30.9 days, P < .0001). Following treprostinil initiation, there was a significant reduction in BNP at 1 week (1439 vs 393 pg/mL, P < .01) and 1 month (1439 vs 242 pg/mL, P = .01). Severity of pulmonary hypertension by echocardiogram improved at 1 month (OR 0.14, CI 95% 0.04-0.48, P = .002). Despite these improvements, overall mortality remained high (35%). There were no adverse events related to treprostinil, including no hypotension, hypoxia, or thrombocytopenia.

CONCLUSIONS

In this cohort, treprostinil use was associated with improved severity of pulmonary hypertension assessed by echocardiogram and decreased BNP, with no significant side effects.

Predicting death or extended length of stay in infants with congenital diaphragmatic hernia

OBJECTIVE

To predict mortality or length of stay (LOS) >109 days (90th percentile) among infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a retrospective analysis using the Children's Hospital Neonatal Database during 2010 to 2014. Infants born >34 weeks gestation with CDH admitted at 22 participating regional neonatal intensive care units were included; patients who were repaired or were at home before admission were excluded. The primary outcome was death before discharge or LOS >109 days. Factors associated with this outcome were used to develop a multivariable equation using 80% of the cohort. Validation was performed in the remaining 20% of infants.

RESULTS

The median gestation and age at referral in this cohort (n=677) were 38 weeks and 6 h, respectively. The primary outcome occurred in 242 (35.7%) infants, and was distributed between mortality (n=180, 27%) and LOS >109 days (n=66, 10%). Regression analyses showed that small for gestational age (odds ratio (OR) 2.5, P=0.008), presence of major birth anomalies (OR 5.9, P<0.0001), 5- min Apgar score ⩽3 (OR 7.0, P=0.0002), gradient of acidosis at the time of referral (P<0.001), the receipt of extracorporeal support (OR 8.4, P<0.0001) and bloodstream infections (OR 2.2, P=0.004) were independently associated with death or LOS >109 days. This model performed well in the validation cohort (area under curve (AUC)=0.856, goodness-of-fit (GF) χ(2), P=0.16) and acted similarly even after omitting extracorporeal support (AUC=0.82, GF χ(2), P=0.05).

CONCLUSIONS

Six variables predicted death or LOS ⩾109 days in this large, contemporary cohort with CDH. These results can assist in risk adjustment for comparative benchmarking and for counseling affected families.

High-Sensitivity Troponin T and N-Terminal Pro-Brain Natriuretic Peptide in Prediction of Outcome in Congenital Diaphragmatic Hernia: Results from a Multicenter, Randomized Controlled Trial

Biomarkers may be helpful in prediction of outcomes of infants with congenital diaphragmatic hernia. The predictive value of high-sensitivity troponin T and N-terminal pro-brain natriuretic peptide was investigated in 128 infants with congenital diaphragmatic hernia. After correction for multiple testing, those biomarkers did not predict severe pulmonary hypertension, death, need of extracorporeal membrane oxygenation, or bronchopulmonary dysplasia.

TRIAL REGISTRATION

Netherlands Trial Registry: 1310.

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.

Antenatal BAY 41-2272 reduces pulmonary hypertension in the rabbit model of congenital diaphragmatic hernia

Infants with congenital diaphragmatic hernia (CDH) fail to adapt at birth because of persistent pulmonary hypertension (PH), a condition characterized by excessive muscularization and abnormal vasoreactivity of pulmonary vessels. Activation of soluble guanylate cyclase by BAY 41-2272 prevents pulmonary vascular remodeling in neonatal rats with hypoxia-induced PH. By analogy, we hypothesized that prenatal administration of BAY 41-2272 would improve features of PH in the rabbit CDH model. Rabbit fetuses with surgically induced CDH at day 23 of gestation were randomized at day 28 for an intratracheal injection of BAY 41-2272 or vehicle. After term delivery (day 31), lung mechanics, right ventricular pressure, and serum NH2-terminal-pro-brain natriuretic peptide (NT-proBNP) levels were measured. After euthanasia, lungs were processed for biological or histological analyses. Compared with untouched fetuses, the surgical creation of CDH reduced the lung-to-body weight ratio, increased mean terminal bronchial density, and impaired lung mechanics. Typical characteristics of PH were found in the hypoplastic lungs, including increased right ventricular pressure, higher serum NT-proBNP levels, thickened adventitial and medial layers of pulmonary arteries, reduced capillary density, and lower levels of endothelial nitric oxide synthase. A single antenatal instillation of BAY 41-2272 reduced mean right ventricular pressure and medial thickness of small resistive arteries in CDH fetuses. Capillary density, endothelial cell proliferation, and transcripts of endothelial nitric oxide synthase increased, whereas airway morphometry, lung growth, and mechanics remained unchanged. These results suggest that pharmacological activation of soluble guanylate cyclase may provide a new approach to the prenatal treatment of PH associated with CDH.

Persistent Challenges in Pediatric Pulmonary Hypertension

Pulmonary hypertension and related pulmonary vascular diseases cause significant morbidities and high mortality and present many unique challenges toward improving outcomes in neonates, infants, and children. Differences between pediatric and adult disease are reflected in controversies regarding etiologies, classification, epidemiology, diagnostic evaluations, and therapeutic interventions. This brief review highlights several key topics reflecting recent advances in the field and identifies persistent gaps in our understanding of clinical pediatric pulmonary hypertension.

B-type natriuretic peptide as a parameter for pulmonary hypertension in children. A systematic review

Pulmonary hypertension (PH) is a life-threatening disease with a high mortality rate and a broad variety of underlying etiologies. The current golden standard for diagnosing PH and monitoring efficiency of treatment is right heart catheterization. As an alternative, serum biomarkers have been suggested. Cardiac troponin T (TnT), brain natriuretic peptide (BNP), and NT-proBNP seem the most potential. The aim of this systematic review was to evaluate the current literature on the prognostic value of these biomarkers in children with PH and their usefulness as a diagnostic tool. A systematic literature search yielded 14 studies on patients ≤18 years with proven PH with (NT-pro)BNP or TnT as primary outcome. TnT is suggested to be a promising biomarker, but its usefulness in clinical practice has not been proven. The levels of (NT-pro)BNP seemed to be reliable within one PH category, but differed significantly between categories. NT-proBNP showed a good correlation with mortality and might have a prognostic value.

CONCLUSION

The lack of absolute levels makes (NT-pro)BNP unsuitable as a diagnostic marker, but in view of the relative changes, it could be used to monitor patients. Further investigation should explore differences in normal (NT-pro)BNP levels between the different categories of PH.

WHAT IS KNOWN

• Pulmonary hypertension is a life-threatening disease. Diagnosis can be challenging in children; the current diagnostic options-right heart catheterization and echocardiography-are invasive and/or investigator-dependent procedures. • Biomarkers could be useful in this context because they are investigator independent and easy to obtain through blood samples. Brain natriuretic peptide (BNP) and its N-terminal cleavage product (NT-proBNP) seem to be the most promising. The value of these biomarkers in the diagnostic approach of PH has already been investigated in adults, with promising results. Pediatric studies are still scarce. What is new: • The levels of BNP and NT-proBNP in pediatric patients differ strongly between the different categories of PH. Within the same category, the levels are more or less equal. • The relative changes could render them a prognostic marker in the follow-up of a certain individual patient. At this moment there is not enough evidence to rely on BNP or NT-proBNP in clinical treatment of patients with PH.

Validation of circulating BNP level >1000 pg/ml in all-cause mortality: A retrospective study

Aim

To determine the primary diseases and prognoses of patients with highly elevated levels of B-type natriuretic peptide (BNP; >1000 pg/ml), with or without heart failure.

Methods

Medical records and echocardiograms of patients with BNP levels that fell within one of three predetermined categories (>1000 pg/ml, 200–1000 pg/ml and <200 pg/ml) were retrospectively reviewed.

Results

There were no significant between-group differences in duration of hospitalization. Patients with BNP levels >1000 pg/ml ( n = 103) or 200–1000 pg/ml ( n = 100) had significantly worse 3-year survival than those with BNP levels <200 pg/ml ( n = 100). The majority of patients (64/103) in the BNP >1000 pg/ml group had heart failure. The main cause of death in patients with other causes of BNP levels >1000 pg/ml (39/103) was community acquired pneumonia.

Conclusion

A BNP level >1000 pg/ml has clinical importance in primary care medicine and hospital settings.

Controversies in the management of severe congenital diaphragmatic hernia

Despite years of progress in perinatal care, severe congenital diaphragmatic hernia (CDH) remains a clinical challenge. Controversies include almost every facet of clinical care: the definition of severe CDH by prenatal and postnatal criteria, fetal surgical intervention, ventilator management, pulmonary hypertension management, use of extracorporeal membrane oxygenation, surgical considerations, and long-term follow-up. Breakthroughs are likely only possible by sharing of experience, collaboration between institutions and innovative therapies within well-designed multicenter clinical trials.