Cardiac dysfunction in congenital diaphragmatic hernia: Pathophysiology, clinical assessment, and management

Neonatal high-frequency oscillatory ventilation: where are we now?

High-frequency oscillatory ventilation (HFOV) is an established mode of respiratory support in the neonatal intensive care unit. Large clinical trial data is based on first intention use in preterm infants with acute respiratory distress syndrome. Clinical practice has evolved from this narrow population. HFOV is most often reserved for term and preterm infants with severe, and often complex, respiratory failure not responding to conventional modalities of respiratory support. Thus, optimal, and safe, application of HFOV requires the clinician to adapt mean airway pressure, frequency, inspiratory:expiratory ratio and tidal volume to individual patient needs based on pathophysiology, lung volume state and infant size. This narrative review summarises the status of HFOV in neonatal intensive care units today, the lessons that can be learnt from the past, how to apply HFOV in different neonatal populations and conditions and highlights potential new advances. Specifically, we provide guidance on how to apply an open lung approach to mean airway pressure, selecting the correct frequency and use of volume-targeted HFOV.

Cardiac function in congenital diaphragmatic hernia

Cardiac function is known to play critical role in the pathophysiological progression and ultimate clinical outcome of patients with congenital diaphragmatic hernia (CDH). While often anatomically normal, the fetal and neonatal heart in CDH can suffer from both right and left ventricular dysfunction. Here we explore the abnormal fetal heart, early postnatal right and left ventricular dysfunction, the interplay between cardiac dysfunction and pulmonary hypertension, evaluation and echocardiographic assessment of the heart, and therapeutic strategies for managing and supporting the pathophysiologic heart and CDH. Further, we take a common clinical scenario and provide clinically relevant guidance for the diagnosis and management of this complex process.

"Heart of the Matter": Cardiac Dysfunction in Congenital Diaphragmatic Hernia

Despite advances in caring for neonates with congenital diaphragmatic hernia (CDH), mortality and morbidity continues to be high. Additionally, the pathophysiology of cardiac dysfunction in this condition is poorly understood. Postnatal cardiac dysfunction in neonates with CDH may be multifactorial with origins in fetal life. Mechanical obstruction, competition from herniated abdominal organs into thoracic cavity combined with redirection of ductus venosus flow away from patent foramen ovale leading to smaller left-sided structures may be a contributing factor. This shunting decreases left atrial and left ventricular blood volume, which may result in altered micro- and macrovascular aberrations affecting cardiac development in the prenatal period. Direct mass effect from herniated intra-abdominal contents restricting cardiac growth and/or reduced left ventricular preload may contribute independently to left ventricular dysfunction in the absence of right ventricular dysfunction and or pulmonary hypertension. With variable clinical phenotypes of cardiac dysfunction, pulmonary hypertension, and respiratory failure in patients with CDH, there is increased need for individualized diagnosis and tailored therapy. Routine use of therapy such as inhaled nitric oxide and sildenafil that induces significant pulmonary vasodilation may be detrimental in left ventricle dysfunction, whereas in a patient with pure right ventricle dysfunction, they may be beneficial. Targeted functional echocardiography serves as a real-time tool for defining the pathophysiology and aids optimization of vasoactive therapy in affected neonates. KEY POINTS: · Cardiac dysfunction in neonates with CDH is multifactorial.. · Postnatal cardiac dysfunction in patients with CDH has its origins in fetal life.. · Right ventricular dysfunction contributes to systemic hypotension.. · Left ventricular dysfunction contributes to systemic hypotension.. · Supportive therapy should be tailored to clinical phenotype..

[Characteristics and Outcome of Neonates With Postnatally Diagnosed Congenital Diaphragmatic Hernia]

INTRODUCTION

Congenital diaphragmatic hernia (CDH) is one of the most severe neonatal malformations with a mortality of 20-35%. Currently, the rate of prenatally recognized CDHs is 60-80%. This study investigated the characteristics and outcome data of children with prenatally unrecognized CDH.

METHODS

Postnatally diagnosed CDH newborns treated at the University Hospital Bonn between 2012 and 2021 were included. Treatment and outcome data were compared according to type of maternity hospital, Apgar values, and between prenatally and postnatally diagnosed CDH.

RESULTS

Of 244 CDH newborns, 22 were included. Comparison for birth in a facility with vs. without pediatric care showed for mortality: 9% vs. 27%, p=0.478; ECMO rate: 9% vs. 36%, p=0.300; age at diagnosis: 84 vs. 129 min, p=0.049; time between intubation and diagnosis: 20 vs. 86 min, p=0.019. Newborns in the second group showed significantly worse values for pH and pCO2. Furthermore, there was a tendency for higher mortality and ECMO rates in children with an Apgar score<7 vs.≥7. Children diagnosed postnatally were significantly more likely to have moderate or severe PH and tended to have cardiac dysfunction more often than those diagnosed prenatally.

DISCUSSION

In our cohort, ca. one in 10 newborns received a postnatal CDH diagnosis. Birth in a facility without pediatric care is associated with later diagnosis, which may favor hypercapnia/acidosis and more severe pulm.

HYPERTENSION

The impact of a care bundle with an emphasis on hemodynamic assessment on the short-term outcomes in neonates with congenital diaphragmatic hernia

OBJECTIVE

To evaluate the short-term outcomes of implementing a care bundle emphasizing frequent hemodynamic assessments by echocardiography in neonates with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

This was a retrospective cohort study of infants with CDH admitted to a quaternary perinatal unit from January 2013 to March 2021. The primary composite outcome was defined as mortality or use of extracorporeal membrane oxygenation or need for respiratory support at discharge.

RESULTS

We identified 37 and 20 CDH infants in Epoch I and II, respectively. More patch repairs (50% vs. 21.9%, p = 0.035) and echocardiograms (6[4-8] vs. 1[0-5], p = 0.003) were performed in Epoch II. While there were no differences in the primary outcome, there was a reduction in mortality in Epoch II (0% vs. 27%, p = 0.01).

CONCLUSION

With the implementation of a CDH care bundle with an emphasis on hemodynamic assessment, we demonstrated a significant reduction in mortality.

The role of point-of-care ultrasound in the management of neonates with congenital diaphragmatic hernia

In the last few years, current evidence has supported the use of point-of-care ultrasound (POCUS) for a number of diagnostic and procedural applications. Considering the valuable information that POCUS can give, we propose a standardized protocol for the management of neonates with a congenital diaphragmatic hernia (CDH-POCUS protocol) in the neonatal intensive care unit. Indeed, POCUS could be a valid tool for the neonatologist through the evaluation of 1) cardiac function and pulmonary hypertension; 2) lung volumes, postoperative pleural effusion or pneumothorax; 3) splanchnic and renal perfusion, malrotations, and/or signs of necrotizing enterocolitis; 4) cerebral perfusion and eventual brain lesions that could contribute to neurodevelopmental impairment. In this article, we discuss the state-of-the-art in neonatal POCUS for which concerns congenital diaphragmatic hernia (CDH), and we provide suggestions to improve its use. IMPACT: This review shows how point-of-care ultrasound (POCUS) could be a valid tool for managing neonates with congenital diaphragmatic hernia (CDH) after birth. Our manuscript underscores the importance of standardized protocols in neonates with CDH. Beyond the well-known role of echocardiography, ultrasound of lungs, splanchnic organs, and brain can be useful. The use of POCUS should be encouraged to improve ventilation strategies, systemic perfusion, and enteral feeding, and to intercept any early signs related to future neurodevelopmental impairment.

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.

Unique Cardiopulmonary Interactions in Congenital Diaphragmatic Hernia: Physiology and Therapeutic Implications

Congenital diaphragmatic hernia (CDH) results in abdominal contents entering the thoracic cavity, affecting both cardiac and pulmonary development. Maldevelopment of the pulmonary vasculature occurs within both the ipsilateral lung and the contralateral lung. The resultant bilateral pulmonary hypoplasia and associated pulmonary hypertension are important components of the pathophysiology of this disease that affect outcomes. Despite prenatal referral to specialized high-volume centers, advanced ventilation strategies, pulmonary hypertension management, and the option of extracorporeal membrane oxygenation, overall CDH mortality remains between 25% and 30%. With increasing recognition that cardiac dysfunction plays a large role in morbidity and mortality in patients with CDH, it becomes imperative to understand the different clinical phenotypes, thus allowing for individual patient-directed therapies. Further research into therapeutic interventions that address the cardiopulmonary interactions in patients with CDH may lead to improved morbidity and mortality outcomes.

Patent ductus arteriosus shunting direction and diameter predict inpatient outcomes in newborns with congenital diaphragmatic hernia

Objective

To evaluate whether the patent ductus arteriosus (PDA) can serve as a predictive factor for inpatient outcomes in congenital diaphragmatic hernia (CDH) patients.

Methods

A retrospective cohort study was conducted on 59 CDH patients at the Capital Institute of Pediatrics from January 2020 to August 2022. Echocardiography was performed at least three times: within 2-3 h after birth, pre-operatively, and post-operatively of CDH surgery. Based on the direction of the PDA shunt in the first echocardiogram, patients were classified into three groups: left-to-right shunting or closed PDA (L-R), bi-directional shunting, and right-to-left shunting (R-L).

Results

The mortality rate was 15.3% (9/59), with all non-survivors having R-L shunting and group mortality of 39.1% (9/23). The direction of the PDA shunt was significantly associated with the duration of ventilation and length of hospital stay (p < 0.05). Decreased PDA diameter or pre-operative shunting direction change towards L-R or bi-directional shunting were associated with higher survival rates, while increased PDA diameter or continuous R-L shunting were associated with higher mortality rates. Pre-operative PDA shunt direction, PDA size after birth and before surgery, gestational age of diagnosis, and shortening fraction before surgery were significantly correlated with patient outcomes. The direction of the preoperative PDA shunt was the most relevant factor among these relationships (p = 0.009, OR 20.6, CI 2.2∼196.1).

Conclusion

Our findings highlight the importance of monitoring changes in PDA shunt directionality and diameter in the early stage after birth, as these parameters may serve as valuable predictors of patient outcomes.

A potential cause of left ventricular dysfunction after surgery in neonates with low-risk congenital diaphragmatic hernia: high-tension repair

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a serious congenital malformation. Given the focus on improving survival in patients with "high-risk" CDH, it is possible that risk factors for low-risk patient with CDH may not be a concern. Left heart failure leads to adverse postoperative outcomes, including the need for extracorporeal membrane oxygenation (ECMO). The purpose of this study was to explore the causes of postoperative left heart failure in the low-risk group.

METHODS

A retrospective study was conducted on newborns with congenital diaphragmatic hernia who were surgically treated in our hospital from January 2018 to March 2022. Children at low risk were divided into three groups according to the intraoperative repair conditions. Group A was defined as grade A defects repaired by direct suture. Group B was defined as a grade B defect repaired by mesh. Group C was a grade B defect repaired by high-tension suture. The age, gender, weight, perioperative echocardiography, and follow-up of the patients were statistically analyzed. The risk factors of left ventricular dysfunction after surgery in neonates with low-risk congenital diaphragmatic hernia were analyzed.

RESULTS

A total of 52 low-risk children were included in the study. For children in the low-risk group, there was no significant difference between the low-tension repair group and the high-tension repair group in terms of operation time, thoracic tube drainage time, hospital stay, and long-term survival rate. Group A and group B showed good left ventricular function, while group C showed more decreased left ventricular EF and LVFS (LVEF 54.06 ± 10.28, LVFS 26.94 ± 5.83, p < 0.001). On the comparison of measures of left ventricular size, the mean values of left ventricular end-diastolic diameters(LVDD) and left ventricular end-systolic diameters (LVDS) were significantly difference in group C. Univariate analysis showed that LHR, o/e LHR, operation time, and high-tension repair were the influencing factors of left ventricular dysfunction. Multivariate logistic regression analysis identified risk factors for high-tension repair. Severe left heart dysfunction occurred in 2 patients with ECMO requirement in the high-tension repair group, although the difference was not significant.

CONCLUSIONS

High-tension repair is a potential cause of left ventricular dysfunction in neonates with low-risk CDH.

Dynamics of pulmonary hypertension severity in the first 48 h in neonates with prenatally diagnosed congenital diaphragmatic hernia

Introduction

Pulmonary hypertension (PH) is one of the major contributing factors to the high morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH). The severity and duration of postnatal PH are an established risk factor for patient outcome; however, the early postnatal dynamics of PH have not been investigated. This study aims to describe the early course of PH in CDH infants, and its relation to established prognostic markers and outcome measures.

Methods

We performed a monocentric retrospective review of neonates with prenatally diagnosed CDH, who received three standardized echocardiographic examinations at 2-6 h, 24, and 48 h of life. The degree of PH was graded as one of three categories: mild/no, moderate, or severe PH. The characteristics of the three groups and their course of PH over 48 h were compared using univariate and correlational analyses.

Results

Of 165 eligible CDH cases, initial PH classification was mild/no in 28%, moderate in 35%, and severe PH in 37%. The course of PH varied markedly based on the initial staging. No patient with initial no/mild PH developed severe PH, required extracorporeal membrane oxygenation (ECMO)-therapy, or died. Of cases with initial severe PH, 63% had persistent PH at 48 h, 69% required ECMO, and 54% died. Risk factors for any PH included younger gestational age, intrathoracic liver herniation, prenatal fetoscopic endoluminal tracheal occlusion (FETO)-intervention, lower lung to head ratio (LHR), and total fetal lung volume (TFLV). Patients with moderate and severe PH showed similar characteristics, except liver position at 24- (p = 0.042) and 48 h (p = 0.001), mortality (p = 0.001), and ECMO-rate (p = 0.035).

Discussion

To our knowledge, this is the first study to systematically assess the dynamics of PH in the first postnatal 48 h at three defined time points. CDH infants with initial moderate and severe PH have a high variation in postnatal PH severity over the first 48 h of life. Patients with mild/no PH have less change in PH severity, and an excellent prognosis. Patients with severe PH at any point have a significantly higher risk for ECMO and mortality. Assessing PH within 2-6 h should be a primary goal in the care for CDH neonates.

Inhaled Nitric Oxide Utilization in Congenital Diaphragmatic Hernia Treated With Extracorporeal Life Support: A Propensity Score Analysis

Although used commonly, ability of inhaled nitric oxide (iNO) to improve outcomes in infants with congenital diaphragmatic hernia (CDH) who receive extracorporeal life support (ECLS) remains controversial. We sought to determine the association between pre-ECLS use of iNO and mortality in infants with CDH from the Extracorporeal Life Support Organization (ELSO) Registry. Neonates who underwent ECLS for CDH were identified from the ELSO Registry from 2009 to 2019. Patients were categorized into those treated with iNO versus not prior to initiating ECLS. Patients were then matched 1:1 for case-mix based on pre-ECLS covariates using the propensity score (PS) for iNO treatment. The matched groups were compared for mortality. The matched cohorts were also compared for ELSO-defined systems-based complications as secondary outcomes. There were a total of 3,041 infants with an overall mortality of 52.2% and a pre-ECLS iNO use rate of 84.8%. With 1:1 matching, there were 461 infants with iNO use and 461 without iNO use. Following matching, use of iNO was not associated with a difference in mortality (odds ratio [OR] = 0.805; 95% confidence interval [CI], 0.621-1.042; p = 0.114). Results were similar in unadjusted analyses, and after controlling for covariates in the full cohort of patients and in the 1:1 matched data. Patients receiving iNO had significantly higher odds of renal complications (OR = 1.516; 95% CI, 1.141-2.014; p = 0.004), but no other significant differences were observed among secondary outcomes. ECLS use of iNO in CDH patients was not associated with a difference in mortality. Future randomized controlled studies are needed to delineate the utility of iNO in CDH patients.

Role of microRNAs in Congenital Diaphragmatic Hernia-Associated Pulmonary Hypertension

Epigenetic regulators such as microRNAs (miRNAs) have a key role in modulating several gene expression pathways and have a role both in lung development and function. One of the main pathogenetic determinants in patients with congenital diaphragmatic hernia (CDH) is pulmonary hypertension (PH), which is directly related to smaller lung size and pulmonary microarchitecture alterations. The aim of this review is to highlight the importance of miRNAs in CDH-related PH and to summarize the results covering this topic in animal and human CDH studies. The focus on epigenetic modulators of CDH-PH offers the opportunity to develop innovative diagnostic tools and novel treatment modalities, and provides a great potential to increase researchers’ understanding of the pathophysiology of CDH.

Right to left ventricular volume ratio is associated with mortality in congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is associated with high neonatal mortality. We performed this study to test the hypothesis that left ventricular (LV) and right ventricular (RV) volumes assessed by three-dimensional echocardiography may be associated with mortality in CDH.

METHODS

This study was a single-center retrospective cohort study involving 35 infants with CDH. RV and LV end-diastolic volume (RVEDV and LVEDV, respectively) were measured by three-dimensional echocardiography and were corrected by birth body weight (BBW) on day 1. RVEDV/BBW, LVEDV/BBW, and LVEDV/RVEDV were compared between CDH survivors and non-survivors. Receiver-operating characteristic curve analysis was performed to assess the predictive ability for mortality of the echocardiographic parameters.

RESULTS

Comparing CDH non-survivors (n = 6) with survivors (n = 29), respectively, RVEDV/BBW was significantly larger (2.54 ± 0.33 vs 1.86 ± 0.35 ml/kg; P < 0.01), LVEDV/BBW was significantly smaller (0.86 ± 0.21 vs 1.22 ± 0.33 ml/kg; P < 0.001), and LVEDV/RVEDV was significantly lower (0.34 ± 0.06 vs 0.66 ± 0.18; P < 0.001). The area under the curve for LVEDV/RVEDV was the largest (0.98).

CONCLUSIONS

Three-dimensional echocardiographic volume imbalance between the RV and LV was remarkable in CDH non-survivors. The LVEDV/RVEDV ratio may be associated with mortality in CDH.

IMPACT

Mortality with congenital diaphragmatic hernia (CDH) is high, and evaluating left and right ventricular structures and functions may be helpful in assessing the prognosis. Three-dimensional (3D) echocardiography indicated that the left ventricular end-diastolic volume/right ventricular end-diastolic volume ratio within 24 h after birth was associated with mortality in CDH infants. The usefulness of this ratio should be validated in prospective multicenter studies involving larger numbers of patients.

Hemodynamic Characterization of Neonates With Congenital Diaphragmatic Hernia-Associated Pulmonary Hypertension by Cardiac Catheterization

We examined the results of cardiac catheterization in infants with congenital diaphragmatic hernia (CDH) from 2009 to 2020. Catheterization confirmed pulmonary arterial hypertension in all cases (n =  17) and identified left ventricular (LV) diastolic dysfunction (LVDD) in 53%. LVDD was associated with greater respiratory morbidity. Preprocedural noninvasive assessment showed inconsistent agreement with catheterization results.

Hidden cardiovascular morbidity in children and young adults born with congenital diaphragmatic hernia: A population-based study

INTRODUCTION

Congenital diaphragmatic (CDH) hernia is a rare congenital malformation with considerable mortality and morbidity in the neonatal period. The majority of the children today survive but little is known about long term cardiovascular morbidity.

MATERIAL AND METHODS

This was a nationwide population-based prospective case-control study within a cohort of Swedish children with CDH, born 1982-2015. Five controls for each patient were randomly sampled from the population. The outcomes were the corresponding International Statistical Classification of Disease (ICD) codes for cardiovascular diagnoses according to ICD 9 and 10.

RESULTS

There was an overrepresentation of cardiovascular diagnoses in the CDH group after one year of age compared to the control group, 8.0vs 0.5% (n = 53 versus n = 16). The risk of having a cardiovascular diagnosis in this CDH group was 15 times higher compared to the control group (HR 15.8, 95% CI: 9-27.6, p < 0.005). The diagnoses of cardiac arrhythmias and systemic hypertension were less common in the CDH group before the age of one year compared to the CDH group beyond the age of one year. Arrhythmia 3.7 vs 15.1%, systemic hypertension 3.7 vs 7.5%.

CONCLUSION

CDH survivors have increased cardiovascular morbidity during childhood and young adulthood. This implies that structured follow up programs, covering cardiovascular morbidity, needs to be developed and should be offered in pediatric and adult care. Being born with CDH seems to be a risk factor for future cardiovascular diagnoses.

LEVEL OF EVIDENCE

Level 3: Case-Control Study.

Diagnosis & management of pulmonary hypertension in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) contributes to neonatal morbidity and mortality worldwide. Pulmonary hypertension (PH) is a key component of CDH pathophysiology and critical consideration for management and therapeutic options. PH associated with CDH has traditionally been attributed to pulmonary vascular maldevelopment and associated lung parenchymal hypoplasia, leading to pre-capillary increase in pulmonary vascular resistance (PVR). However, there is increasing recognition that left ventricular hypoplasia, dysfunction and elevated end diastolic pressure may contribute to post-capillary pulmonary hypertension in CDH patients. The interplay of these mechanisms and associated dysfunction in the right and left ventricles results in variable hemodynamic phenotypes in CDH. Clinical assessment of individual phenotype may help guide personalized management strategies, including effective use of pulmonary vasodilators and extra-corporeal membrane oxygenation. Ongoing investigation of the underlying mechanisms of PH in CDH, and efficacy of physiology-based treatment approaches may support improvement in outcomes in this challenging condition.

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.

Echocardiographic Assessment of Pulmonary Hypertension in Neonates with Congenital Diaphragmatic Hernia Using Pulmonary Artery Flow Characteristics

Background: Assessment of pulmonary hypertension (PH) is essential in neonates with congenital diaphragmatic hernia (CDH). Echocardiography is widely established to quantify PH severity, but currently used parameters have inherent limitations. The aim of our study was to investigate the prognostic utility of the index of the pulmonary artery acceleration time to the right ventricular ejection time (PAAT:ET) in CDH neonates assessed using echocardiography. Methods: PAAT:ET values were prospectively measured in CDH neonates on admission, on day of life (DOL) 2 and DOL 5−7. Optimal cut-off values to predict mortality and need for ECMO were calculated and PAAT:ET values were compared between non-ECMO survivors, ECMO-survivors, and ECMO-non-survivors. Results: 87 CDH neonates were enrolled and 39 patients required ECMO therapy. At baseline, PAAT:ET values were significantly lower in ECMO patients compared to non-ECMO patients (p < 0.001). ECMO survivors and ECMO non-survivors had similar values at baseline (p = 0.967) and DOL 2 (p = 0.124) but significantly higher values at DOL 5−7 (p = 0.003). Optimal PAAT:ET cut-off for predicting ECMO was 0.290 at baseline and 0.310 for predicting non-survival in patients on ECMO at DOL 5−7. Conclusion: PAAT:ET is a feasible parameter for early risk assessment in CDH neonates.

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.

Echocardiographic measures of ventricular-vascular interactions in congenital diaphragmatic hernia

OBJECTIVE

To evaluate the utility of echocardiographic measures of ventricular-vascular interactions in predicting death or ECMO in congenital diaphragmatic hernia (CDH).

DESIGN

In this single center retrospective study, early (<48 hour age) Doppler ECHOs of neonates (≥34 weeks gestation) with CDH (n = 58) were reviewed. ECHO measures of the relationship of right ventricular (RV) contractility and pulmonary hypertension (PH) were selected: Ratios of 1. pulmonary artery acceleration time to pulmonary ejection time (PAAT/PET) 2. tricuspid annular plane systolic excursion, a measure of regional RV function, to PAAT (TAPSE/PAAT) 3. patent ductus arteriosus (PDA) flow velocity time integral (VTI) from right to left (PDA/RLVTI) 4. PDA flow duration from right to left (PDA/RL) and 5. TAPSE to RV systolic pressure (TAPSE/RVSP). Statistical analyses included t-test and chi-square test and receiver operating characteristic curves were generated.

RESULTS

Our cohort (n = 58) comprised 34 (59%) males and predominantly (81%) left sided CDH. Of these, 34 (58.6%) infants died or received ECMO and 24 (41.4%) survived without ECMO. RVSP and PDA/RL VTI were higher, and RV TAPSE, PAAT/PET, TAPSE/PAAT and TAPSE/RVSP ratios were all significantly lower in the death/ECMO group. PDA/RLVTI ratio had the highest area under the curve (0.76); values ≥ 0.6 had high specificity [88% (95% C.I. 62-98%)] and positive predictive value [88% (95% C.I. 65-96%)] for adverse outcomes.

CONCLUSION(S)

Novel early ECHO parameters which combine RV function and PH severity were found to be feasible and prognostic in CDH. A detailed non-invasive assessment of ventricular-vascular interactions is important for risk-stratification in this population.

The heart in congenital diaphragmatic hernia: Knowns, unknowns, and future priorities

There is growing recognition that the heart is a key contributor to the pathophysiology of congenital diaphragmatic hernia (CDH), in conjunction with developmental abnormalities of the lung and pulmonary vasculature. Investigations to date have demonstrated altered fetal cardiac morphology, notably relative hypoplasia of the fetal left heart, as well as early postnatal right and left ventricular dysfunction which appears to be independently associated with adverse outcomes. However, many more unknowns remain, not least an understanding of the genetic and cellular basis for cardiac dysplasia and dysfunction in CDH, the relationship between fetal, postnatal and long-term cardiac function, and the impact on other parts of the body especially the developing brain. Consensus on how to measure and classify cardiac function and pulmonary hypertension in CDH is also required, potentially using both non-invasive imaging and biomarkers. This may allow routine assessment of the relative contribution of cardiac dysfunction to individual patient pathophysiological phenotype and enable better, individualized therapeutic strategies incorporating targeted use of fetal therapies, cardiac pharmacotherapies, and extra-corporeal membrane oxygenation (ECMO). Collaborative, multi-model approaches are now required to explore these unknowns and fully appreciate the role of the heart in CDH.

[Therapy and Outcome of Neonates with Congenital Diaphragmatic Hernia and Congenital Heart Defects]

Die Mortalität von Patienten mit isoliert auftretenden angeborenen Zwerchfellhernien liegt in spezialisierten Zentren bei 20-40%. Wesentliche, das Outcome beeinflussende Faktoren, sind die bestehende Lungenhypoplasie, eine daraus resultierende pulmonale Hypertonie, sowie das Vorliegen weiterer Fehlbildungen. Begleitfehlbildungen wie angeborene Herzfehler treten bei ca. 18% aller Neonaten mit Zwerchfellhernie auf. Schwere angeborene Herzfehler wie das hypoplastische Linksherz Syndrom zeigen sich in ca. 8% der Fälle. In einer retrospektiven Analyse des Patientenkollektivs unserer Klinik zwischen 01/2012 und 12/2018 wurde das prä- und postnatale Management, sowie das Outcome von Neugeborenen mit der Kombination aus angeborenen Herzfehlern und Zwerchfellhernien untersucht. Im Studienzeitraum wurden in unserer Klinik 156 Neugeborene mit Zwerchfellhernie behandelt. Bei 10 Patienten (6,4%) lag zusätzlich ein schwerer, bei 11 Patienten (7,1%) ein moderater Herzfehler vor. 6/21 Patienten verstarben im Verlauf des Krankenhausaufenthaltes, davon 3 am ersten Lebenstag. Es zeigte sich eine deutlich geringere Mortalität bei Patienten mit Zwerchfellhernie und moderatem Herzfehler im Vergleich zu schwerem Herzfehler (9 vs. 50%). Besonders hoch lag die Mortalität bei Kindern mit einem univentrikulären Herzen. Trotz einer deutlich reduzierten Prognose bei der Kombination aus angeborenem Herzfehler und Zwerchfellhernie muss nicht generell mit einer infausten Prognose gerechnet werden. In spezialisierten Zentren kann ein kurativer Ansatz erfolgen.The mortality of patients with isolated congenital diaphragmatic hernia (CDH) in specialized centers is 20-40%. The main factors influencing the outcome are the underlying pulmonary hypoplasia, the resulting pulmonary hypertension and the presence of other malformations. Concomitant malformations such as congenital heart defects occur in around 18% of all neonates with a diaphragmatic hernia. Serious congenital heart defects such as hypoplastic left heart syndrome occur in approximately 8% of cases. In a retrospective analysis of the patient collective of our hospital between 01/2012 and 12/2018, the prenatal and postnatal management as well as the outcome of newborns with a combination of congenital heart defects and diaphragmatic hernias were examined. During the study period, 156 newborns with diaphragmatic hernias were treated at our institution. In 10 patients (6.4%) there was also a severe, and in 11 patients (7.1%) a moderate heart defect. 6/21 patients died during their hospital stay, 3 of them on the first day of life. There was a significantly lower mortality in patients with diaphragmatic hernia and moderate heart defects compared to severe heart defects (9 vs. 50%). The mortality in children with a univentricular heart was particularly high. Despite a significantly reduced prognosis for the combination of congenital heart defects and diaphragmatic hernia, generally a poor prognosis does not have to be expected. A curative approach can be achieved in specialized centers.

NeoAPACHE II. Relationship Between Radiographic Pulmonary Area and Pulmonary Hypertension, Mortality, and Hernia Recurrence in Newborns With CDH

Congenital diaphragmatic hernia is a rare disease with high mortality and morbidity due to pulmonary hypoplasia and pulmonary hypertension. The aim of the study is to investigate the relationship between radiographic lung area and systolic pulmonary artery pressure (sPAP) on the first day of life, mortality, and hernia recurrence during the first year of life in infants with a congenital diaphragmatic hernia (CDH). A retrospective data collection was performed on 77 CDH newborns. Echocardiographic sPAP value, deaths, and recurrence cases were recorded. Lung area was calculated by tracing the lung's perimeter, excluding mediastinal structures, and herniated organs, on the preoperative chest X-ray performed within 24 h after birth. Logistic and linear regression analyses were performed. Deceased infants showed lower areas and higher sPAP values. One square centimeter of rising in the total, ipsilateral, and contralateral area was associated with a 22, 43, and 24% reduction in mortality risk. sPAP values showed a decreasing trend after birth, with a maximum of 1.84 mmHg reduction per unitary increment in the ipsilateral area at birth. Recurrence patients showed lower areas, with recurrence risk decreasing by 14 and 29% per unit increment of the total and ipsilateral area. In CDH patients, low lung area at birth reflects impaired lung development and defect size, being associated with increased sPAP values, mortality, and recurrence risk. Clinical Trial Registration: The manuscript is an exploratory secondary analysis of the trial registered at ClinicalTrials.gov with identifier NCT04396028.

Early Left Ventricular Dysfunction and Severe Pulmonary Hypertension Predict Adverse Outcomes in "Low-Risk" Congenital Diaphragmatic Hernia

OBJECTIVES

Given significant focus on improving survival for "high-risk" congenital diaphragmatic hernia, there is the potential to overlook the need to identify risk factors for suboptimal outcomes in "low-risk" congenital diaphragmatic hernia cases. We hypothesized that early cardiac dysfunction or severe pulmonary hypertension were predictors of adverse outcomes in this "low-risk" congenital diaphragmatic hernia population.

DESIGN

This is a retrospective cohort study using data from the Congenital Diaphragmatic Hernia Study Group registry. "Low-risk" congenital diaphragmatic hernia was defined as Congenital Diaphragmatic Hernia Study Group defect size A/B without structural cardiac and chromosomal anomalies. Examined risk factors included left ventricular dysfunction, right ventricular dysfunction, and severe pulmonary hypertension on the first postnatal echocardiogram. The primary outcome was composite adverse events, defined as either death, extracorporeal membrane oxygenation utilization, oxygen requirement on day 30 of life, or hospitalization greater than or equal to 8 weeks. Multivariable adjustment was performed with logistic regression and inverse probability weighting.

SETTING

Neonatal index hospitalization for congenital diaphragmatic hernia.

PATIENTS

"Low-risk" congenital diaphragmatic hernia infants born between January 2015 and December 2018.

INTERVENTIONS

First postnatal echocardiogram performed within 24 hours from birth.

MEASUREMENTS AND MAIN RESULTS

Seven-hundred seventy-eight patients were identified as "low-risk" congenital diaphragmatic hernia. Left ventricular dysfunction, right ventricular dysfunction, and severe pulmonary hypertension were present in 10.8%, 20.5%, and 57.5%, respectively. The primary outcome occurred in 21.3%. Death occurred in 3.0% and 9.1% used extracorporeal membrane oxygenation. On unadjusted analysis, all three risk factors were associated with the primary outcome. On all multivariable adjustment methods, left ventricular dysfunction and severe pulmonary hypertension remained significant predictors of adverse outcomes while right ventricular dysfunction no longer demonstrated any effect.

CONCLUSIONS

Early left ventricular dysfunction and severe pulmonary hypertension are independent predictors of adverse outcomes among "low-risk" congenital diaphragmatic hernia infants. Early recognition may lead to interventions that can improve outcome in this at-risk cohort.

Retinal findings in neonates with congenital diaphragmatic hernia and extracorporeal membrane oxygenation

PURPOSE

To evaluate the prevalence of retinal pathologies in neonates with congenital diaphragmatic hernia (CDH) receiving extracorporeal membrane oxygenation (ECMO) therapy.

METHODS

This retrospective study included consecutive infants that received ECMO therapy for CDH at our hospital between 2012 and 2018. Retinal changes were assessed by mydriatic indirect funduscopy. Recorded patient parameters include gestational age (GA), type of delivery, duration of ECMO therapy, duration of inhalative oxygen supplementation, and postmenstrual age at fundus examination.

RESULTS

Of 54 infants that were treated by ECMO therapy for CDH during the study period, 27 were medically stable enough to receive funduscopic examination and were thus included in the study. Mean GA of these 27 children was 37.3 weeks (range 33.1-40.6) and mean duration of inhalative oxygen supplementation was 12.8 weeks (range 2.7-56.4). Retinal changes were observed in 3 neonates (11.1%). These included multiple midperipheral blot intraretinal hemorrhages in 5 eyes of 3 children and retinopathy of prematurity (ROP) in 2 eyes (stage 3 and stage 2, respectively, without plus disease) of 1 child (GA 35.0 weeks; duration of inhalative oxygen supplementation, 11.9 weeks). In all infants, retinal changes regressed without therapeutic intervention.

CONCLUSIONS

Neonates treated with ECMO due to CDH may exhibit retinal hemorrhages, however usually without need for intervention. Prematurely born infants receiving ECMO may develop ROP and thus require ROP screening examinations.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.

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.

Ventricular Dysfunction Is a Critical Determinant of Mortality in Congenital Diaphragmatic Hernia

Rationale: Congenital diaphragmatic hernia (CDH) is an anomaly with a high morbidity and mortality. Cardiac dysfunction may be an important and underrecognized contributor to CDH pathophysiology and determinant of disease severity.Objectives: Our aim was to investigate the association between early, postnatal ventricular dysfunction and outcome among infants with CDH.Methods: Multicenter, prospectively collected data in the CDH Study Group (CDHSG) registry, abstracted between 2015 and 2018, were evaluated. Ventricular function on early echocardiograms, defined as obtained within the first 48 hours of life, was categorized into four hierarchical groups: normal function, right ventricular dysfunction only (RV_dys), left ventricular dysfunction only (LV_dys), and combined RV and LV dysfunction (RV&LV_dys). Univariate, multivariate, and Cox proportional hazards regression analyses were performed.Measurements and Main Results: Cardiac function data from early echocardiograms were available for 1,173 (71%) cases and categorized as normal in 711 (61%), RV_dys in 182 (15%), LV_dys in 61 (5%), and combined RV&LV_dys in 219 (19%) cases. Ventricular dysfunction was significantly associated with prenatal diagnosis, CDHSG stage, intrathoracic liver, and patch repair (all P < 0.001). Survival varied by category: normal function, 80%; RV_dys, 74%; LV_dys, 57%; and RV&LV_dys, 51% (P < 0.001). The adjusted risk of death (hazard ratio) for cases with LV_dys was 1.96 (95% confidence interval [CI], 1.29-2.98; P = 0.020) and for cases with RV&LV_dys was 2.27 (95% CI, 1.77-2.92; P = 0.011). All cardiac dysfunction categories were associated with use of extracorporeal membrane oxygenation (P < 0.005).Conclusions: Early ventricular dysfunction occurs frequently in CDH and is an independent determinant of severity and clinical outcome.

Validation of a Prediction Rule for Mortality in Congenital Diaphragmatic Hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly with a mortality of ∼27%. The Congenital Diaphragmatic Hernia Study Group (CDHSG) developed a simple postnatal clinical prediction rule to predict mortality in newborns with CDH. Our aim for this study is to externally validate the CDHSG rule in the European population and to improve its prediction of mortality by adding prenatal variables.

METHODS

We performed a European multicenter retrospective cohort study and included all newborns diagnosed with unilateral CDH who were born between 2008 and 2015. Newborns born from November 2011 onward were included for the external validation of the rule (n = 343). To improve the prediction rule, we included all patients born between 2008 and 2015 (n = 620) with prenatally diagnosed CDH and collected pre- and postnatal variables. We build a logistic regression model and performed bootstrap resampling and computed calibration plots.

RESULTS

With our validation data set, the CDHSG rule had an area under the curve of 79.0%, revealing a fair predictive performance. For the new prediction rule, prenatal herniation of the liver was added, and absent 5-minute Apgar score was taken out. The new prediction rule revealed good calibration, and with an area under the curve of 84.6%, it had good discriminative abilities.

CONCLUSIONS

In this study, we externally validated the CDHSG rule for the European population, which revealed fair predictive performance. The modified rule, with prenatal liver herniation as an additional variable, appears to further improve the model's ability to predict mortality in a population of patients with prenatally diagnosed CDH.

Inhaled Nitric Oxide Is Associated with Improved Oxygenation in a Subpopulation of Infants with Congenital Diaphragmatic Hernia and Pulmonary Hypertension

OBJECTIVES

To determine which patients with congenital diaphragmatic hernia (CDH) and pulmonary hypertension (PH) benefit from inhaled nitric oxide (iNO) treatment by comparing characteristics and outcomes of iNO responders to nonresponders.

STUDY DESIGN

We performed a retrospective chart review of infants with CDH treated at our center between 2011 and 2016. In a subset of patients, iNO was initiated for hypoxemia or echocardiographic evidence of extrapulmonary right to left shunting. Initial post-treatment blood gases were reviewed, and patients were classified as responders (increased PaO₂ >20 mm Hg) or nonresponders. Baseline characteristics, echocardiograms and outcomes were compared between groups with Fisher exact tests and Mann-Whitney t tests, as appropriate.

RESULTS

During the study period, 95 of 131 patients with CDH (73%) were treated with iNO. All patients with pretreatment echocardiograms (n = 90) had echocardiographic evidence of PH. Thirty-eight (40%) patients met treatment response criteria. Responders had significant improvements in PaO₂ (51 ± 3 vs 123 ± 7 mm Hg, P < .01), alveolar-arterial gradient (422 ± 30 vs 327 ± 27 mm Hg, P < .01), and PaO₂ to FiO₂ ratio (82 ± 10 vs 199 ± 15 mm Hg, P < .01). Nonresponders were more likely to have left ventricular systolic dysfunction (27% vs 8%, P = .03) on echocardiogram. Responders were less likely to require extracorporeal membrane support (50 vs 24%, P = .02).

CONCLUSIONS

iNO treatment is associated with improved oxygenation and reduced need for ECMO in a subpopulation of patients with CDH with PH and normal left ventricular systolic function.

Myocardial strain in newborn infants with tracheomalacia due to vascular rings, a pilot study

Background: Vascular rings (VR) may cause severe tracheomalacia and upper airway obstruction (UAO). Increased pulmonary artery pressure and cardiac dysfunction have been described in patients with chronic UAO, but has not been investigated in infants with obstruction associated with VR. The aim of this study is to evaluate myocardial strain in infants with UAO due to VR.Method: Demographic characteristics, respiratory symptoms, percentage of tracheal obstruction measured and classified using Computer Tomography, and lung function testing (LFT) were collected. Left (LV) and right ventricle (RV) systolic functions were measured using speckle tracking echocardiography longitudinal strain analysis (LS). Pulmonary artery pressure was evaluated using maximal tricuspid regurgitation jet velocity (TR) and LV end-systolic eccentricity index (EI).Results: Fifteen cases were included in the study, six had mild tracheal obstruction (<50%), nine moderate-severe obstruction (≥50%). LV LS and RV LS were significantly reduced in cases with moderate to severe airway obstruction cases compared to those with mild airway obstruction (LV LS -15.9 versus -19.9%; RV LS -15.7 versus -20.5%, p = .04 and p = .02, respectively). Respiratory symptoms were more pronounced in moderate-severe cases. No significant differences in TR, EI, and LFT were observed.Conclusions: In cases of VR with severe tracheomalacia RV and LV myocardial strain is reduced, suggesting secondary cardiac dysfunction.

Congenital diaphragmatic hernia-associated cardiac dysfunction

There is increasing evidence that cardiac dysfunction is a key contributor to CDH pathophysiology. Dysfunction in both right and left ventricles is common in the early neonatal period, contributes to clinical disease severity, and is associated with adverse outcomes including death and ECMO use. Early and routine assessment of ventricular function and pulmonary artery pressure may guide individualized clinical decision-making, including use of pulmonary vasodilators, cardiotropes, ECMO, and timing of surgical repair. Minimizing cardiac dysfunction, whether by prenatal, postnatal or perinatal treatment strategies, may lead to improved outcome in CDH.

The assessment of cardiac function with tissue Doppler imaging in fetuses with congenital diaphragmatic hernia

Introduction: This study aimed to evaluate the cardiac function of fetuses with congenital diaphragmatic hernia by conventional echocardiography and spectral tissue Doppler imaging (s-TDI) and to evaluate the relationship between cardiac function and the severity of pulmonary hypoplasia. We also aimed to investigate the effect of diaphragmatic hernia side on fetal cardiac function.Methods: Fetal cardiac function were evaluated in 28 fetuses (20 with left-sided and 8 with right-sided) complicated with isolated congenital diaphragmatic hernia (CDH) and 56 gestational age matched control in this single center prospective study. s-TDI measurements were obtained at the right atrioventricular valve annulus. The annular peak velocities and their ratios, the time periods of cardiac cycle and myocardial performance index were calculated.Results: In comparison to controls, significantly prolonged isovolumetric contraction time (ICT') and isovolumetric relaxation time (IRT') and, significantly shortened ejection time (ET') were observed in fetuses with CDH by s-TDI. Fetuses with CDH also had higher myocardial performance index (MPI') z-scores compared to controls. There were no significant differences in terms of s-TDI cardiac function parameters between fetuses with right- and left-sided CDH. In correlation analysis, a significant positive correlation was found between ET' value and o/e LHR.Conclusion: The signs of both systolic and diastolic altered function were observed in fetuses with CDH with s-TDI independent of the side of the hernia, and a significant positive correlation was observed between fetal cardiac systolic function and the severity of pulmonary hypoplasia.

Propofol Formulation Affects Myocardial Function in Newborn Infants

This study aimed to evaluate the effects of propofol in diluted and undiluted formulations on cardiac function in infants. Infants > 30 days received propofol sedation for central line insertion. Cases were divided into two groups: those who received undiluted 1% propofol (P1%); and those who received a diluted formulation (Pd) of equal volumes propofol 1% and 0.9% NaCl. Echocardiograms were performed pre (t₀)-, immediately post (t₁)-, and 1-h post (t₂) propofol administration. Myocardial deformation was assessed with tissue Doppler imaging (TDI) analysis and peak longitudinal strain (LS). 18 cases were included: nine (50%) P1% and nine (50%) Pd. In the P1% group, TDI velocities and LS were significantly reduced at t₁ and t₂. In the Pd Group, only TDI velocities in the left ventricle were reduced at t₁, but not at t₂. Dilution of propofol may minimize myocardial dysfunction while maintaining adequate sedation in infants. Further comparative studies are needed to investigate the safety and efficacy of this approach.

Expression of soluble receptor for advanced glycation end products is associated with disease severity in congenital diaphragmatic hernia

Pulmonary hypertension (PH) and lung hypoplasia are major contributors to morbidity and mortality in newborns with congenital diaphragmatic hernia (CDH). The soluble receptor for advanced glycation end products (sRAGE) is a marker of endothelial function and might be associated with disease severity in CDH newborns. In a cohort of 30 CDH newborns and 20 healthy control newborns, sRAGE concentration was measured at birth and at 6 h, 12 h, 24 h, 48 h, and 7-10 days. In healthy newborns, sRAGE was significantly higher at birth and at 48 h compared with CDH newborns (both P < 0.001). Among CDH newborns, sRAGE was significantly lower at birth (P = 0.033) and at 7-10 days (P = 0.035) in patients receiving extracorporeal membrane oxygenation (ECMO) compared with patients not receiving ECMO. In contrast, CDH newborns receiving ECMO had significantly higher values at 6 h (P = 0.001), 12 h (P = 0.004), and 48 h (0.032). Additionally, sRAGE correlated significantly with PH severity, intensity and duration of mechanical ventilation, and prenatally assessed markers of CDH severity (lung size, liver herniation). The probability to receive ECMO therapy was five times higher in CDH newborns with sRAGE concentrations below the calculated cutoff of 650 pg/ml at birth (P = 0.002) and nine times higher in CDH newborns with sRAGE concentrations above the cutoff of 3,500 pg/ml at 6 h (P = 0.001). These findings suggest a potential involvement of sRAGE in the pathophysiology of CDH and may act as a therapeutic target in future treatment approaches.

Prognostic utility of noninvasive estimates of pulmonary vascular compliance in neonates with congenital diaphragmatic hernia

AIM

To evaluate echocardiographic indices of pulmonary vascular resistance and right ventricular (RV) function in predicting death or ECMO in congenital diaphragmatic hernia (CDH).

METHODS

In this single center study, early (<48 h) echocardiograms of neonates with CDH (n = 47) were reviewed by a single reader for the ratio of tricuspid regurgitant velocity to velocity time integral at the pulmonary valve (TRV/VTIpv), TRV2/VTIpv, RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE). Receiver operating characteristic curves were generated for each parameter to obtain optimal cutoff values.

RESULTS

Infants who died or received ECMO (n = 30) had significantly higher TRV/VTIpv and TRV2/VTIpv, and lower VTIpv, RV FAC and TAPSE, compared to the 17 survivors without ECMO. For TRV2/VTIpv and TRV/VTI at cutoffs of 1.3 and 0.38 respectively, the sensitivities were 92.3 (95% CI 75-99.1%) and 96 (95% CI 80.4-99.9%), specificities were 78.6 (49.2-95.4%) and 71.4 (42-91.6%), positive predictive values were 89 (75-95.6%) and 86.2 (73.2-93.5%) and negative predictive values were 84.6 (58.5-95.5%) and 90.9 (58.7-98.6%).

CONCLUSION

Early echocardiographic evidence of pulmonary hypertension and RV dysfunction predicts outcome in CDH. Further studies utilizing these indices to guide therapeutic decision-making are warranted.

LEVEL OF EVIDENCE

Level 1 for diagnostic study.

Haematopoietic alterations in neonates with congenital diaphragmatic hernia receiving extracorporeal membrane oxygenation support

BACKGROUND

Extracorporeal membrane oxygenation procedure (ECMO) has been established in the therapy of respiratory insufficient infants with congenital diaphragmatic hernia. In congenital diaphragmatic hernia newborns, a delay in transfer to an ECMO centre is associated with a sharp increase in mortality. Predictive factors for ECMO support are urgently needed. We evaluated the routine parameters of the first blood withdrawal after birth in congenital diaphragmatic hernia infants, hypothesizing that early signs in bone marrow affecting haematology parameters for early regulation of potentially post birth hypoxia are predictive factors for ECMO support.

MATERIALS AND METHODS

In 44 patients born with congenital diaphragmatic hernia, differential blood cell count from the first blood withdrawal after birth was examined. Descriptive statistics included median, 95% confidence intervals, minimum and maximum differentiating ECMO/early mortality vs. no ECMO. Odds ratios with CI were calculated by binary logistic regression analysis. Best predictive markers were further checked in combination with the liver-up situation in two factorial regression models.

RESULTS

In our cohort, the survival rate was 77.3% (34/44). While 18 neonates received ECMO support, 26 experienced no ECMO during hospital stay. Odds ratio calculations showed that risk for ECMO support increases with augmenting leukocytes, erythrocytes, haemoglobin, haematocrit, mean cell volume and absolute immature granulocytes. Further, the risk advanced in line with the severity of congenital diaphragmatic hernia assessed by prenatal ultrasound.

CONCLUSIONS

We conclude that these parameters are associated with disease severity in congenital diaphragmatic hernia newborns and may be considered potentially predictive biomarkers for the necessity of ECMO support.

Preoperative cardiopulmonary evaluation in specific neonatal surgery

Preoperative assessment of surgical neonates often relates to issues of prematurity, low birth weight, or associated malformations. This review explores the preoperative cardiopulmonary evaluation in specific newborn surgical populations, the role of echocardiography in congenital diaphragmatic hernia perioperative management, the impact of bronchopulmonary dysplasia in the ex-preterm surgical neonate and a brief discussion on the risk of general anesthesia and specific anesthetic considerations for any surgical neonate. Newborns with congenital anomalies requiring early general surgical intervention should have an assessment for congenital heart disease. In the asymptomatic neonate, a thorough physical exam may be sufficient preoperatively. Neonates born with esophageal atresia or anorectal malformations should have a full evaluation for VACTERL associations. Initial echocardiography in congenital diaphragmatic hernia is used to evaluate anatomy, but there is emerging evidence to suggest the use of echocardiography in the ongoing surveillance of CDH to influence the timing of surgical intervention. Bronchopulmonary dysplasia is present in up to 40% of ex-premature neonates and increases the risk of postoperative apneas and need for ventilatory support. However, all surgical neonates have an increased risk of post-operative apneas, and the need for surgical intervention should be balanced with the risk of general anesthesia.

Ventricular Dysfunction, Interdependence, and Mechanical Dispersion in Newborn Infants with Congenital Diaphragmatic Hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is an important cause of mortality and morbidity in the neonatal period. Pulmonary hypertension and pulmonary hypoplasia are key pathological findings. Cardiac function may also be an important determinant of disease severity, prognostic indicator, and therapeutic target in CDH.

OBJECTIVE

The aim of this study was to assess ventricular mechanics and synchrony in infants with CDH and controls using speckle tracking echocardiography (STE).

METHODS

Retrospective analysis was performed of echocardiograms obtained in the first 48 h of life in 27 infants with CDH and 20 controls. STE-derived longitudinal strain (LS) was measured in the right and left ventricles (RV, LV). Circumferential strain (CS) and radial strain (RS) were additionally measured in the LV. Mechanical dispersion (MD), a measure of synchrony, was assessed by calculation of the standard deviation of time to peak systolic strain in six ventricular segments.

RESULTS

RV LS and LV LS, LV CS, and LV RS were significantly reduced in CDH compared to controls. In the LV free wall, LS and RS were significantly reduced in CDH. LV LS correlated significantly with RV LS in CDH cases (r2 = 0.37, p = 0.002), but not controls (r2 = 0.19, p = 0.06). LV LS also correlated with LV MD in CDH (r2 = 0.25, p = 0.01) but not controls (r2 = 0.02, p = 0.54).

CONCLUSIONS

Global impairment of RV and LV systolic function are present in newborn infants with CDH and are associated with primary left ventricular dysfunction, ventricular interdependence, and MD.

Early Postnatal Ventricular Dysfunction Is Associated with Disease Severity in Patients with Congenital Diaphragmatic Hernia

OBJECTIVE

To assess patterns of postnatal ventricular function and their relationship to prenatal and postnatal markers of disease severity in infants with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

In this observational case-control study of cardiac function in infants with CDH in the first 5 days of life, systolic and diastolic function in the right ventricle (RV) and left ventricle (LV) were assessed using speckle tracking echocardiography-derived global strain and tissue Doppler imaging. Correlation between cardiac function and prenatal observed:expected total fetal lung volume (TFLV), oxygenation index (OI), duration of intubation, and hospital length of stay were assessed.

RESULTS

All measures of systolic and diastolic function were significantly reduced in the CDH group (n = 25) compared with controls (n = 20) at <48 hours, and were improved by 72-120 hours. LV global systolic longitudinal strain (GLS) correlated with prenatal TFLV (R² = 0.32; P = .03), OI (R² = 0.35; P < .001), duration of intubation (R² = 0.24; P = .04), and length of stay (R² = 0.4; P = .006). Mean (SD) LV GLS at <48 hours was significantly lower in infants with CDH who did not survive and/or required ECMO compared with those who did not: -11.5 (5.3)% vs -16.9 (5.3)% (P = .02).

CONCLUSIONS

RV and LV function are impaired in the transitional period in infants with CDH. Early LV systolic function correlates with prenatal and postnatal markers of clinical disease severity and may be an important determinant of disease severity and therapeutic target in CDH. These findings support regular assessment of cardiac function in CDH and investigational trials of targeted cardiovascular therapies.

Clinical and echocardiographic risk factors for extubation failure in infants with congenital diaphragmatic hernia

INTRODUCTION

Infants after surgical correction of congenital diaphragmatic hernia are at high risk for extubation failure, but little is known about contributing factors. Therefore, our study aimed to analyze clinical and echocardiographic parameters.

MATERIALS AND METHODS

Data of 34 infants with congenital diaphragmatic hernia treated at our department (July 2013-December 2015) were analyzed. Inclusion criteria were: presence of congenital diaphragmatic hernia and echocardiography performed within 48 hours before the first, and, in case of reintubation, the final extubation attempt. Infants were allocated to group A (extubation failure) and group B (extubation successful).

RESULTS

Extubation failure occurred in 12/34 infants (35%). Infants in group A had a higher proportion of intrathoracic liver herniation (P = 0.001, OR 17 [2.8/104.5]) and lower rates of the lung-to-head ratio (P = 0.042, 95% CI [-0.4/20]), even as higher rates of extracorporeal membrane oxygenation (P = 0.001, 95% CI [2.7/80.9]). The oxygenation index and the PaO₂ /FiO₂ ratio differed significantly between both groups (both P = 0.000; 95% CI [-11/-4.1] and [79/215], respectively). The mean airway pressure and fraction of inspired oxygen prior to extubation was significantly higher in group A (P = 0.008; 95% CI [-3.9/-1.4]; P = 0.000; 95% CI [-0.6/-0.2], respectively). In addition, the respiratory severity score was higher in group A (P = 0.000; 95% CI [-7.3/-2.6]). In group A, administration of sildenafil and the vasoactive inotropic score were significantly higher (P = 0.037; OR 9 [0.9/88.6] and P = 0.013; 95% CI [-14/-1.8], respectively). More infants in group A had need for a surgical patch repair of the diaphragm (P = 0.017; OR 7.2 [1.3/41.1]) and showed higher rates of relevant pleural effusions prior the extubation (P = 0.021; OR 6 [1.2/29.5]). The total duration of the ventilation and the length of hospital stay were longer in group A (P = 0.004; 95% CI [-915/-190] and P = 0.000; 95% CI [-110/-39], respectively). The prevalence of pulmonary hypertension was more frequent in group A (P = 0.012; OR 12 [1.3/114]), the time to peak velocity in the main pulmonary artery was significantly lower in group A (P = 0.024; 95% CI [2/25.6]), and these infants suffered more often from cardiac dysfunction (P = 0.007; OR 10 [1.6/63.1]).

CONCLUSION

Our results demonstrate that extubation failure in infants with a congenital diaphragmatic hernia is associated with several clinical and echocardiographic risk factors.

Circulating microRNAs are associated with Pulmonary Hypertension and Development of Chronic Lung Disease in Congenital Diaphragmatic Hernia

Pulmonary hypertension (PH) contributes to high mortality in congenital diaphragmatic hernia (CDH). A better understanding of the regulatory mechanisms underlying the pathology in CDH might allow the identification of prognostic biomarkers and potential therapeutic targets. We report the results from an expression profiling of circulating microRNAs (miRNAs) in direct post-pulmonary blood flow of 18 CDH newborns. Seven miRNAs differentially expressed in children that either died or developed chronic lung disease (CLD) up to 28 days after birth, compared to those who survived without developing CLD during this period, were identified. Target gene and pathway analyses indicate that these miRNAs functions include regulation of the cell cycle, inflammation and morphogenesis, by targeting molecules responsive to growth factors, cytokines and cellular stressors. Furthermore, we identified hub molecules by constructing a protein-protein interaction network of shared targets, and ranked the relative importance of the identified miRNAs. Our results suggest that dysregulations in miRNAs let-7b-5p, -7c-5p, miR-1307-3p, -185-3p, -8084, -331-3p and -210-3p may be detrimental for the development and function of the lungs and pulmonary vasculature, compromise cardiac function and contribute to the development of CLD in CDH. Further investigation of the biomarker and therapeutic potential of these circulating miRNAs is encouraged.

Response to pulmonary vasodilators in infants with congenital diaphragmatic hernia

BACKGROUND

Congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia, cardiac dysfunction and pulmonary hypertension. Inhaled nitric oxide (iNO) and milrinone are commonly used pulmonary vasodilators in CDH. We studied the hemodynamic effects of iNO and milrinone in infants with CDH.

METHODS

A retrospective chart review was performed of all CDH infants admitted to two regional perinatal centers and infants classified into three groups: No-iNO group; iNO-responders and iNO-nonresponders. Oxygenation and hemodynamic effects of iNO and milrinone were assessed by blood gases and echocardiography.

RESULTS

Fifty-four percent (39/72) of infants with CDH received iNO and 31% of these infants (12/39) had complete oxygenation response to iNO. Oxygenation response to iNO was not associated with a decrease in right ventricular pressures (RVP) or ECMO use. Four infants (33%) in the iNO-responder group and eight infants (30%) in the iNO-nonresponder group received milrinone. Milrinone lowered RVP and improved ejection fraction (EF). Response to iNO was associated with improved oxygenation to milrinone and increased survival following ECMO (67 vs. 20% among nonresponders).

CONCLUSIONS

Response to inhaled nitric oxide in combination with milrinone may be associated with improved oxygenation and better survival after ECMO in infants with CDH.

Pulmonary hypertension in congenital diaphragmatic hernia patients: Prognostic markers and long-term outcomes

Prenatal observed/expected lung-to-head ratio (O/E LHR) by ultrasound correlates with postnatal mortality for congenital diaphragmatic hernia (CDH) patients. The aim of this study is to determine if O/E LHR correlates with pulmonary hypertension (PH) outcomes for CDH patients.

METHODS

A single center retrospective chart review was performed for CDH neonates from January 1, 2006, to December 31, 2015, (REB #1000053124) to include prenatal O/E LHR, liver position, first arterial blood gas, repair type, echocardiogram (ECHO), and lung perfusion scan (LPS) results up to 5years of age.

RESULTS

Of 153 newborns, 123 survived (80.4%), 58 (37.9%) had prenatal O/E LHR, and 42 (27.5%) had postnatal ECHO results. High mortality risk neonates (O/E LHR ≤45%) correlated with higher right ventricular systolic pressure (RVsp) at birth. Generally PH resolved by age 5years. LPS results did not change over time (p>0.05) regardless of initial PH severity, suggesting that PH resolution did not correlate with increased ipsilateral lung perfusion to offload the right ventricle.

CONCLUSION

Prenatal prognostic markers correlated with initial PH severity for CDH newborns, but PH resolved over time despite fixed perfusion bias to the lungs. These results suggest favorable PH outcomes for CDH patients who survive beyond infancy.

TYPE OF STUDY

Retrospective Cohort Study.

LEVEL OF EVIDENCE

3b.

Continuous intravenous sildenafil as an early treatment in neonates with congenital diaphragmatic hernia

BACKGROUND

Pulmonary hypertension (PH) is an important contributor of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). Treatment options are limited, but sildenafil might improve oxygenation and PH in neonates with CDH.

OBJECTIVE

Aim of this study is to assess effects of intravenous sildenafil on oxygenation and PH in neonates with CDH.

METHODS

A retrospective chart review was performed in all neonates with CDH born in our institution between September 2012 and December 2014. Indication for sildenafil was an OI > 15, PH > 2/3 systemic pressure, or a difference in pre- and postductal oxygen saturation (≥8%). A sildenafil bolus was administered followed by a maintenance infusion of 1.6 mg/kg/d. Primary outcome was improved oxygenation after starting sildenafil. Patients were compared according to improvement in oxygenation (responder vs non-responder).

RESULTS

A total of 26 of 44 neonates were treated with intravenous sildenafil and in all sildenafil were initiated within the first 24 h of life (median age 3.1 h). Improved oxygenation was observed in 11 infants (42.3%). Among the 15 non-responders (57.6%) ECMO was started in 13 and two infants died without ECMO. Vasopressor support increased significantly during the first hours after commencing sildenafil in responders and non-responders. Echocardiographic indices demonstrated an effect on pulmonary arterial pressure within the first 24 h after starting sildenafil.

CONCLUSIONS

Treatment of neonates with intravenous sildenafil during the first day of life was associated with acute improvement in oxygenation in more than 40% of patients. However, a significant increase in vasopressor support was observed.

Gata-6 expression is decreased in diaphragmatic and pulmonary mesenchyme of fetal rats with nitrofen-induced congenital diaphragmatic hernia

PURPOSE

Congenital diaphragmatic hernia (CDH) and associated pulmonary hypoplasia are thought to be caused by a malformation of the underlying diaphragmatic and airway mesenchyme. GATA binding protein 6 (Gata-6) is a zinc finger-containing transcription factor that plays a crucial role during diaphragm and lung development. In the primordial diaphragm, Gata-6 expression is restricted to mesenchymal compartments of the pleuroperitoneal folds (PPFs). In addition, Gata-6 is essential for airway branching morphogenesis through upregulation of mesenchymal signaling. Recently, mutations in Gata-6 have been linked to human CDH. We hypothesized that diaphragmatic and pulmonary Gata-6 expression is decreased in the nitrofen-induced CDH model.

METHODS

Time-mated rats were exposed to either nitrofen or vehicle on gestational day 9 (D9). Fetal diaphragms (n = 72) and lungs (n = 48) were microdissected on selected timepoints D13, D15 and D18, and divided into control and nitrofen-exposed specimens (n = 12 per sample, timepoint and experimental group, respectively). Diaphragmatic and pulmonary gene expression of Gata-6 was analyzed by qRT-PCR. Immunofluorescence-double staining for Gata-6 was combined with the diaphragmatic mesenchymal marker Gata-4 and the pulmonary mesenchymal marker Fgf-10 to evaluate protein expression and localization in fetal diaphragms and lungs.

RESULTS

Relative mRNA expression levels of Gata-6 were significantly decreased in PPFs on D13 (0.57 ± 0.21 vs. 2.27 ± 1.30; p < 0.05), developing diaphragms (0.94 ± 0.59 vs. 2.28 ± 1.89; p < 0.05) and lungs (0.56 ± 0.16 vs. 0.71 ± 0.39; p < 0.05) on D15 and fully muscularized diaphragms (1.20 ± 1.10 vs. 2.52 ± 1.86; p < 0.05) and differentiated lungs (0.56 ± 0.05 vs. 0.77 ± 0.14; p < 0.05) on D18 of nitrofen-exposed fetuses compared to controls. Confocal laser scanning microscopy demonstrated markedly diminished immunofluorescence of Gata-6 mainly in diaphragmatic and pulmonary mesenchyme, which was associated with a reduction of proliferating mesenchymal cells in nitrofen-exposed fetuses on D13, D15, and D18 compared to controls.

CONCLUSION

Decreased Gata-6 expression during diaphragmatic development and lung branching morphogenesis may disrupt mesenchymal cell proliferation, causing malformed PPFs and reduced airway branching, thus leading to diaphragmatic defects and pulmonary hypoplasia in the nitrofen-induced CDH model.

Milrinone in congenital diaphragmatic hernia - a randomized pilot trial: study protocol, review of literature and survey of current practices

Background

Congenital diaphragmatic hernia (CDH) is commonly associated with pulmonary hypoplasia and pulmonary hypertension (PH). PH associated with CDH (CDH-PH) is frequently resistant to conventional pulmonary vasodilator therapy including inhaled nitric oxide (iNO) possibly due to right and left ventricular dysfunction. Milrinone is an intravenous inotrope and lusitrope with pulmonary vasodilator properties and has been shown anecdotally to improve oxygenation in PH. We developed this pilot study to determine if milrinone infusion would improve oxygenation in neonates ≥36 weeks postmenstrual age (PMA) with CDH.

Methods/design

Data on pulmonary vasodilator management and outcome of CDH patients was collected from 18 university NICUs affiliated with the Neonatal Research Network (NRN) from 2011 to 2012. The proposed pilot will be a masked, placebo–controlled, multicenter, randomized trial of 66 infants with CDH with an oxygenation index (OI) ≥10 or oxygen saturation index (OSI) ≥5. The primary outcome is the oxygenation response, as determined by change in OI at 24 h after initiation of study drug. As secondary outcomes, we will determine oxygenation at 48 h and 72 h post-infusion, right ventricular pressures on echocardiogram and the incidence of systemic hypotension, arrhythmias, intracranial hemorrhage, survival without extracorporeal membrane oxygenation, and chronic lung disease (oxygen need at 28 days postnatal age). Finally, we will evaluate the pulmonary and nutritional status at 4, 8 and 12 months of age using a phone questionnaire.

Results

Three hundred thirty-seven infants with CDH were admitted to NRN NICUs in 2011 and 2012 of which 275 were ≥36 weeks PMA and were exposed to the following pulmonary vasodilators: iNO (39%), sildenafil (17%), milrinone (17%), inhaled epoprostenol (6%), intravenous epoprostenol (3%), and intravenous PGE1 (1%). ECMO was required in 36% of patients. Survival to discharge was 71%.

Discussion

CDH is an orphan disease with high mortality with few randomized trials evaluating postnatal management. Intravenous milrinone is a commonly used medication in neonatal/pediatric intensive care units and is currently used in 17% of patients with CDH within the NRN. This pilot study will provide data and enable further studies evaluating pulmonary vasodilator therapy in CDH.

Trial registration

ClinicalTrials.gov; NCT02951130; registered 14 October 2016.