Atrial Septal Defects Accelerate Pulmonary Hypertension Diagnoses in Premature Infants

Cardiovascular Sequelae of Bronchopulmonary Dysplasia in Preterm Neonates Born before 32 Weeks of Gestational Age: Impact of Associated Pulmonary and Systemic Hypertension

Bronchopulmonary dysplasia (BPD) remains the most common respiratory disorder of prematurity for infants born before 32 weeks of gestational age (GA). Early and prolonged exposure to chronic hypoxia and inflammation induces pulmonary hypertension (PH) with the characteristic features of a reduced number and increased muscularisation of the pulmonary arteries resulting in an increase in the pulmonary vascular resistance (PVR) and a fall in their compliance. BPD and BPD-associated pulmonary hypertension (BPD-PH) together with systemic hypertension (sHTN) are chronic cardiopulmonary disorders which result in an increased mortality and long-term problems for these infants. Previous studies have predominantly focused on the pulmonary circulation (right ventricle and its function) and developing management strategies accordingly for BPD-PH. However, recent work has drawn attention to the importance of the left-sided cardiac function and its impact on BPD in a subset of infants arising from a unique pathophysiology termed postcapillary PH. BPD infants may have a mechanistic link arising from chronic inflammation, cytokines, oxidative stress, catecholamines, and renin-angiotensin system activation along with systemic arterial stiffness, all of which contribute to the development of BPD-sHTN. The focus for the treatment of BPD-PH has been improvement of the right heart function through pulmonary vasodilators. BPD-sHTN and a subset of postcapillary PH may benefit from afterload reducing agents such as angiotensin converting enzyme inhibitors. Preterm infants with BPD-PH are at risk of later cardiac and respiratory morbidities as young adults. This paper reviews the current knowledge of the pathophysiology, diagnosis, and treatment of BPD-PH and BPD-sHTN. Current knowledge gaps and emerging new therapies will also be discussed.

Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: Basing Care on Physiology

Bronchopulmonary dysplasia (BPD) is the heterogeneous chronic lung developmental disease of prematurity, which is often accompanied by multisystem comorbidities. Pulmonary vascular disease and pulmonary hypertension (PH) contribute significantly to the pathogenesis and pathophysiology of BPD and dramatically influence the outcomes of preterm infants with BPD. When caring for those patients, clinicians should consider the multitude of phenotypic presentations that fall under the "BPD-PH umbrella," reflecting the need for matching therapies to specific physiologies to improve short- and long-term outcomes. Individualized management based on the patient's prenatal and postnatal risk factors, clinical course, and cardiopulmonary phenotype needs to be identified and prioritized to provide optimal care for infants with BPD-PH.

Pulmonary Hypertension in Established Bronchopulmonary Dysplasia: Physiologic Approaches to Clinical Care

Preterm infants with bronchopulmonary dysplasia (BPD) are prone to develop pulmonary hypertension (PH). Strong laboratory and clinical data suggest that antenatal factors, such as preeclampsia, chorioamnionitis, oligohydramnios, and placental dysfunction leading to fetal growth restriction, increase susceptibility for BPD-PH after premature birth. Echocardiogram metrics and serial assessments of NT-proBNP provide useful tools to diagnose and monitor clinical course during the management of BPD-PH, as well as monitoring for such complicating conditions as left ventricular diastolic dysfunction, shunt lesions, and pulmonary vein stenosis. Therapeutic strategies should include careful assessment and management of underlying airways and lung disease, cardiac performance, and systemic hemodynamics, prior to initiation of PH-targeted drug therapies.

Risk factors for isolated atrial septal defect secundum morbidity

Atrial septal defect secundum is a common type of congenital heart defect and even more common among children born premature. The aim of this study was to assess premature birth as a potential associated risk factors for cardiac morbidity in children with isolated ASD II. In this retrospective national registry-based case-control study all children born in Sweden between 2010 and 2015 with an isolated ASD II diagnosis were included. Association between premature birth and cardiac morbidity in children with isolated ASD II was assessed by different outcomes-models using conditional logistic regression and adjustments were made for confounding factors. Overall, 11% of children with an isolated ASD II received treatment for heart failure. Down syndrome was the only independent risk factors for associated with cardiac morbidity in children with ASD II (OR = 2.25 (95%CI 1.25-4.07). Preterm birth in children was not associated with an increased risk of ASD II cardiac morbidity.

Bronchopulmonary dysplasia - associated pulmonary hypertension: An updated review

Bronchopulmonary dysplasia (BPD) is the leading cause of chronic lung disease in infants and the commonest complication of prematurity. Advances in respiratory and overall neonatal care have increased the survival of extremely low gestational age newborns, leading to the continued high incidence of BPD. Pulmonary hypertension (PH) represents the severe form of the pulmonary vascular disease associated with BPD, and affects almost one-third of infants with moderate to severe BPD. PH responds suboptimally to pulmonary vasodilators and increases morbidity and mortality in BPD infants. An up-to-date knowledge of the pathogenesis, pathophysiology, diagnosis, treatment, and outcomes of BPD-PH can be helpful to develop meaningful and novel strategies to improve the outcomes of infants with this disorder. Therefore, our multidisciplinary team has attempted to thoroughly review and summarize the latest advances in BPD-PH in preventing and managing this morbid lung disorder of preterm infants.

Atrial septal defect closure is associated with improved clinical status in patients ≤ 10 kg with bronchopulmonary dysplasia

Patients with bronchopulmonary dysplasia (BPD) have shown clinical improvement after secundum atrial septal defect (ASD) closure. We sought to determine if this post-ASD closure improvement is secondary to the expected course in BPD patients or related to the closure itself. A novel BPD-ASD score was created to assess patients' clinical status (higher score = worse disease) and applied to 10 BPD-ASD inpatients weighing ≤ 10 kg who underwent ASD closure. The score and its subcomponents were retrospectively calculated serially ranging from 8 weeks pre- to 8 weeks post-intervention, and pre- and post-intervention score slopes were created. These slopes were compared using mixed regression modeling with an interaction term. There was a significant difference in pre- versus post-intervention slope with the most score drop the first week post-intervention (-2.1 + /- 0.8, p = 0.014). The mean score also dropped through weeks 2 (slope -0.8 + /- 0.8, p = 0.013) and 4 (slope -1.0 + /- 0.5, p = 0.001) post-intervention. There was a significant difference in pre- and post-intervention slopes for diuretics (p = 0.018) and the combined score of respiratory support, FiO2 need, and respiratory symptoms (p = 0.018). This study demonstrated significant improvement in BPD-ASD score, diuretic need, and respiratory status after ASD closure in BPD-ASD patients ≤ 10 kg that was outside of the natural course of BPD. Our study was limited by its small, single-center, retrospective nature. Future studies should be performed in a larger multicenter population to both validate the scoring system and compare to non-intervention infants.

Outpatient prescription of pulmonary vasodilator therapy to preterm children with bronchopulmonary dysplasia

AIM

The use of pulmonary vasodilator therapy in children born preterm is largely unknown. Our aim was to map prescription patterns in children with bronchopulmonary dysplasia in Sweden.

METHODS

This was a descriptive national registry-based study of children <7 years who had been prescribed a pulmonary vasodilator during 2007-2017, were born preterm and classified as having bronchopulmonary dysplasia. Information on prescriptions, patient characteristics and comorbidities were retrieved from the Swedish Prescribed Drug Register and linked to other national registers.

RESULTS

The study included 74 children, 54 (73%) born at 22-27 weeks' gestation and 20 (27%) at 28-36 weeks. Single therapy was most common, n = 64 (86.5%), and sildenafil was prescribed most frequently, n = 69 (93%). Bosentan, iloprost, macitentan and/or treprostinil were used mainly for combination therapies, n = 10 (13.5%). Patent ductus arteriosus or atrial septal defect were present in 29 (39%) and 25 (34%) children, respectively, and 20 (69%) versus 3 (12%) underwent closure. Cardiac catheterisation was performed in 19 (26%) patients. Median duration of therapy was 4.6 (1.9-6.8, 95% CI) months. Mortality was 9%.

CONCLUSION

Preterm children with bronchopulmonary dysplasia were prescribed pulmonary vasodilators, often without prior catheterisation. Sildenafil was most commonly used. Diagnostic tools, effects, and drug safety need further evaluation.

Update on shunt closure in neonates and infants

Introduction: Cardiac defects that result in shunting are the most common types of congenital heart anomalies. Although these lesions can be simple, they can cause significant hemodynamic changes and can be challenging to manage in neonates and infants. Over the recent decades, the development of new transcatheter techniques and devices has made it safe and feasible to manage such defects when indicated, even in the smallest of patients. Understanding these interventional procedures is essential in order to manage those patients.Areas covered: In this article, we review the techniques and experience for closure of atrial septal defects, ventricular septal defects, patent ductus aarteriosus,as well as coronary arteriovenous malformations and fistulas in neonates and infants. Literature review of PubMed articles was performed through January 2021, with focus on the latest data and results of the usage of interventional techniques in treating these lesions specifically in this age-group.Expert opinion: Significant shunting lesions can be particularly challenging to manage in neonates and infants. Newer lower profile devices will likely continue to be developed in the future, allowing their use for transcatheter interventions in even smaller patients and those with more complex anatomy.

Update on pediatric pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) causes high morbidity and mortality in children. In this review, we discuss advances in diagnosis and treatment of this disorder.

RECENT FINDINGS

Proceedings published from the 2018 World Symposium updated the definition of pulmonary hypertension to include all adults and children with mean pulmonary artery pressure more than 20 mmHg. Targeted PAH therapy is increasingly used off-label, but in 2017, bosentan became the first Food and Drug Administration-targeted PAH therapy approved for use in children.

SUMMARY

In recent years, advanced imaging and clinical monitoring have allowed improved risk stratification of pulmonary hypertension patients. New therapies, approved in adults and used off-label in pediatric patients, have led to improved outcomes for affected children.

Pulmonary hypertension is an important co-morbidity in developmental lung diseases of infancy: Bronchopulmonary dysplasia and congenital diaphragmatic hernia

Bronchopulmonary dysplasia (BPD) following preterm birth and congenital diaphragmatic hernia (CDH) are both forms of developmental lung disease that may result in persistent pulmonary and pulmonary vascular morbidity in childhood. The pulmonary vascular disease (PVD) which accompanies BPD and CDH is due to developmental abnormalities and ongoing perinatal insults. This may be accompanied by evidence of elevated right heart pressures and pulmonary vascular resistance, leading to diagnosis of pulmonary hypertension (PH). The development of PH in these conditions is associated with increased morbidity and mortality in the vulnerable BPD and CDH populations. We present a review of PVD pathogenesis and evaluation in BPD and CDH and discuss management of related sequelae of PH co-morbidity for affected infants.

Neonatal and Postneonatal Pulmonary Hypertension

During transition at birth with ventilation of the lungs, pulmonary vascular resistance (PVR) decreases from high fetal values, leading to an 8 to 10-fold increase in pulmonary blood flow (Qp). In some infants, this transition does not occur, resulting in pulmonary hypertension (PH). In infants, PH can present as: (a) primary PH in term neonates (idiopathic), (b) PH secondary to lung disease or hypoplasia in term infants, (c) acute PH in preterm infants with respiratory distress syndrome (RDS), (d) chronic PH with bronchopulmonary dysplasia (BPD) in preterm infants and (e) post-neonatal PH. A hemodynamically significant patent ductus arteriosus (PDA) can exacerbate PH in preterm infants due to increased Qp. Pulmonary vein stenosis (PVS) can complicate BPD with PH. Diagnosis of PH is based on clinical features, echocardiography and, in some intractable cases, cardiac catheterization. Therapy of PH includes oxygen, invasive or non-invasive ventilation, correction of acidosis, surfactant and selective and non-selective pulmonary vasodilators such as inhaled nitric oxide and sildenafil, respectively. Early closure of a hemodynamically significant PDA has the potential to limit pulmonary vascular remodeling associated with BPD and PH. The role of thiamine in pathogenesis of PH is also discussed with the recent increase in thiamine-responsive acute pulmonary hypertension in early infancy. Recognition and prompt therapy of PH can prevent right ventricular dysfunction, uncoupling and failure.

ATS Core Curriculum 2020. Pediatric Pulmonary Medicine

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine, in a 3- to 4-year recurring cycle of topics. These topics will be presented at the 2020 International Conference. Below is the pediatric pulmonary medicine core, including pediatric hypoxemic respiratory failure; modalities in noninvasive management of chronic respiratory failure in childhood; surgical and nonsurgical management of congenital lung malformations; an update on smoke inhalation lung injury; an update on vaporizers, e-cigarettes, and other electronic delivery systems; pulmonary complications of sarcoidosis; pulmonary complications of congenital heart disease; and updates on the management of congenital diaphragmatic hernia.

Pediatric Pulmonary Arterial Hypertension

Pulmonary hypertension (PH), the syndrome of increased pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children and is associated with a variety of potential underlying causes. Several pulmonary arterial hypertension-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome, but there is still no cure for most patients. This review provides a description of select causes of PH encountered in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH. Available evidence for specific classes of PH-targeted therapies in pediatrics is discussed.

Transcatheter Closing Atrial Septal Defect in a Child With Hereditary Spherocytosis

A 3-year-old girl was admitted to our hospital for the correction of atrial septal defect (ASD). Open heart operation with cardiopulmonary bypass is dangerous because the patient also had hereditary spherocytosis, which put her at risk for hemolytic anemia. Therefore, percutaneous transcatheter closure for ASD was chosen and performed successfully, which avoided the erythrocyte damage caused by cardiopulmonary bypass. This is the first time such a case has been reported, and we present an alternative approach for ASD with hereditary spherocytosis.