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Background: Interventional therapies for severe pulmonary arterial hypertension (PAH) can provide right ventricular (RV) decompression and preserve cardiac output. Transcatheter stent placement in a residual ductus arteriosus (PDA) is one potentially effective option in critically ill infants and young children with PAH. We sought to assess recovery of RV function by echocardiographic strain in infants and young children following PDA stenting for acute PAH., Methods: Retrospective review of patients < 2 years old who underwent PDA stenting for acute PAH. Clinical data were abstracted from the electronic medical record. RV strain (both total and free wall components) was assessed from echocardiographic images at baseline and 3, 6, and 12 months post-intervention, as well as at last echocardiogram., Results: Nine patients underwent attempted ductal stenting for PAH. The median age at intervention was 38 days and median weight 3.7 kg. One-third (3of 9) of patients had PAH associated with a congenital diaphragmatic hernia. PDA stents were successfully deployed in eight patients. Mean RV total strain was - 14.9 ± 5.6% at baseline and improved to - 23.8 ± 2.2% at 6 months post-procedure (p < 0.001). Mean free wall RV strain was - 19.5 ± 5.4% at baseline and improved to - 27.7 ± 4.1% at 6 months (p = 0.002). Five patients survived to discharge, and four patients survived 1 year post-discharge., Conclusion: PDA stenting for severe, acute PAH can improve RV function as assessed by strain echocardiography. The quantitative improvement is more prominent in the first 6 months post-procedure and stabilizes thereafter., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

It is increasingly recognised that diverse genetic respiratory disorders present as severe pulmonary hypertension (PH) in the neonate and young infant, but many controversies and uncertainties persist regarding optimal strategies for diagnosis and management to maximise long-term outcomes. To better define the nature of PH in the setting of developmental lung disease (DEVLD), in addition to the common diagnoses of bronchopulmonary dysplasia and congenital diaphragmatic hernia, we established a multidisciplinary group of expert clinicians from stakeholder paediatric specialties to highlight current challenges and recommendations for clinical approaches, as well as counselling and support of families. In this review, we characterise clinical features of infants with DEVLD/DEVLD-PH and identify decision-making challenges including genetic evaluations, the role of lung biopsies, the use of imaging modalities and treatment approaches. The importance of working with team members from multiple disciplines, enhancing communication and providing sufficient counselling services for families is emphasised to create an interdisciplinary consensus., Competing Interests: Conflict of interest: E.D. Austin reports grants from the NIH and a leadership role with TBX4Life. C. Galambos reports leadership roles with PPHNet and TBX4Life. D. Yung reports grants from Merck, Janssen and the NIH. S.O. Vargas reports grants from the Chan Zuckerberg Initiative, consultancy fees from Vertex Pharmaceuticals, lecture fees from the American Academy of Allergy, Asthma & Immunology, participation on a data safety monitoring board or advisory board with Millipore Sigma, and a leadership role with the Society for Pediatric Pathology. E.O. Jackson reports support for attending meetings from Seattle Children's Hospital. E.C. Whalen reports consultancy fees from the Pulmonary Hypertension Association Care Center and a leadership role with PPHNet. N.M. Villafranco reports support for attending meetings from the Children's Hospital of Philadelphia. S.H. Abman reports grants from the NHLBI (U01 HL12118), consultancy fees from Chiesi, and participation on a data safety monitoring board or advisory board with Bayer Pharmaceuticals and the NHLBI. The remaining authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2024.)

Objectives: Evaluate the correlation of non-invasive echocardiographic estimates of right ventricular systolic pressure with measurements on cardiac catheterization in children with pulmonary hypertension., Design: Retrospective chart review., Setting: Quaternary academic children's hospital., Participants: Patients younger than 18 years with a diagnosis of pulmonary hypertension and confirmatory cardiac catheterization from 2015 to 2018., Measurements and Main Results: We analyzed the correlation between measures of right ventricular systolic pressure using nonparametric Spearman rho (ρ) with statistical significance set at p < 0.05., Results: Children (N = 111) with biventricular circulation, strictly defined pulmonary hypertension, and adequate tricuspid regurgitation on echocardiogram to estimate right ventricular systolic pressure using the modified Bernoulli equation. Median age and weight were 4.3 years and 14.4 kg. Median right ventricular systolic pressure estimated by tricuspid regurgitant velocity on echocardiography was 55 mmHg (IQR 45-75 mmHg) plus right atrial pressure. On cardiac catheterization, median right ventricular systolic pressure was 57 mmHg (IQR 46-75 mmHg). Echocardiographic estimates of right ventricular systolic pressure were moderately well correlated with right ventricular systolic pressure directly measured on catheterization (ρ = 0.44, 95% CI 0.27-0.6, p < 0.001) with a median difference of 4 mmHg (IQR -10 to 17). Subgroup analysis revealed that echocardiography and catheterization measurements correlated well in children with suprasystemic right ventricular pressure on cardiac catheterization (ρ = 0.75, 95% CI 0.51-0.99, p < 0.001) although catheterization measurements were a median of 26 mmHg (IQR 12-31) higher than echocardiographic estimates in this subgroup., Conclusions: In children with pulmonary hypertension, echocardiographic estimates of right ventricular pressure correlated moderately well with gold standard measurements by cardiac catheterization with stronger correlation in children with suprasystemic right ventricular pressures. This is reassuring for clinicians who must rely on echocardiography for risk stratification before anesthetizing children with pulmonary hypertension., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To determine the prevalence of exercise-induced pulmonary hypertension (PH) among long-survivors of congenital diaphragmatic hernia repair., Study Design: This is a single-center, retrospective cohort study of CDH survivors who underwent exercise stress echocardiography (ESE) at Boston Children's Hospital from January 2006 to June 2020. PH severity was assessed by echocardiogram at baseline and after exercise. Patients were categorized by right ventricular systolic pressure (RVSP) after exercise: Group 1 - no or mild PH; and Group 2 - moderate or severe PH (RVSP ≥ 60 mmHg or ≥ ½ systemic blood pressure)., Results: Eighty-four patients with CDH underwent 173 ESE with median age 8.1 (4.8 - 19.1) years at first ESE. Sixty-four patients were classified as Group 1, 11 as Group 2, and 9 had indeterminate RVSP with ESE. Moderate to severe PH after exercise was found in 8 (10%) patients with no or mild PH at rest. Exercise-induced PH was associated with larger CDH defect size, patch repair, use of ECMO, supplemental oxygen at discharge, and higher WHO functional class. Higher VE/VCO2 slope, lower peak oxygen saturation, and lower percent predicted FEV1, and FEV1/FVC ratio were associated with Group 2 classification. ESE changed management in 9/11 Group 2 patients. PH was confirmed in all 5 Group 2 patients undergoing cardiac catheterization after ESE., Conclusions: Among long-term CDH survivors, 10% had moderate-severe exercise-induced PH on ESE, indicating ongoing pulmonary vascular abnormalities. Further studies are needed to optimally define PH screening and treatment for patients with repaired CDH., Competing Interests: Declaration of Competing Interest The authors declare no financial conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Mycobacterium tuberculosis, the causative agent of human tuberculosis (hTB), is a close evolutionary relative of Mycobacterium bovis, which causes bovine tuberculosis (bTB), one of the most damaging infectious diseases to livestock agriculture. Previous studies have shown that the pathogenesis of bTB disease is comparable to hTB disease, and that the bovine and human alveolar macrophage (bAM and hAM, respectively) transcriptomes are extensively reprogrammed in response to infection with these intracellular mycobacterial pathogens. In this study, a multi-omics integrative approach was applied with functional genomics and GWAS data sets across the two primary hosts (Bos taurus and Homo sapiens) and both pathogens (M. bovis and M. tuberculosis). Four different experimental infection groups were used: 1) bAM infected with M. bovis, 2) bAM infected with M. tuberculosis, 3) hAM infected with M. tuberculosis, and 4) human monocyte-derived macrophages (hMDM) infected with M. tuberculosis. RNA-seq data from these experiments 24 h post-infection (24 hpi) was analysed using three computational pipelines: 1) differentially expressed genes, 2) differential gene expression interaction networks, and 3) combined pathway analysis. The results were integrated with high-resolution bovine and human GWAS data sets to detect novel quantitative trait loci (QTLs) for resistance to mycobacterial infection and resilience to disease. This revealed common and unique response macrophage pathways for both pathogens and identified 32 genes (12 bovine and 20 human) significantly enriched for SNPs associated with disease resistance, the majority of which encode key components of the NF-κB signalling pathway and that also drive formation of the granuloma., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pulmonary vasodilator treatment can improve hemodynamics, right ventricular function, symptoms, and survival in pediatric pulmonary hypertension (PH). However, clinical trial data are lacking due to many constraints. One major limitation is the lack of relevant trial endpoints reflective of hemodynamics or functional status in patients in whom standard exercise testing is impractical, unreliable, or not reproducible. The Kids Mod PAH trial (Mono- vs. Duo Therapy for Pediatric Pulmonary Arterial Hypertension) is an ongoing multicenter, Phase III, randomized, open-label, pragmatic trial to compare the safety and efficacy of first-line combination therapy (sildenafil and bosentan) to first-line monotherapy (sildenafil alone) in 100 pediatric patients with PH across North America. Investigators will measure participants' physical activity with a research-grade, wrist-worn actigraphy device at multiple time points as an exploratory secondary outcome. Vector magnitude counts per minute and activity intensity will be compared between the treatment arms. By directly and noninvasively measuring physical activity in the ambulatory setting, we aim to identify a novel, simple, inexpensive, and highly reproducible approach for quantitative assessment of exercise tolerance in pediatric PH. These data will increase the field's understanding of the effect of pulmonary vasodilator treatment on daily activity - a quantitative measure of functional status and wellbeing in pediatric PH and a potential primary outcome for future clinical trials in children with cardiopulmonary disorders., Competing Interests: The authors declare no conflict of interest., (© 2024 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Objective: To evaluate the feasibility, tolerability, and adherence with wearable actigraphy devices among infants and children with pulmonary arterial hypertension (PAH)., Study Design: This multicenter, prospective, observational study included children ages 0-6 years with and without PAH. Participants wore the ActiGraph wGT3X-BT on the hip and FitBit Inspire on the wrist during waking hours for 14 days. Steps, vector magnitude counts per minute, activity intensity, heart rate, and heart rate variability were compared between groups., Results: Forty-seven participants (18 PAH, 29 control) were enrolled from 10 North American sites. PAH patients were mostly functional class II (n = 16, 89%) and treated with oral medications at the time of enrollment. The number of wear days was not significantly different between the groups (ActiGraph: 10 [95% CI: 5.5, 12.2] in PAH vs 8 [4, 12] in control, P = .20; FitBit 13 [10, 13.8] in PAH vs 12 [8, 14] in control, P = .87). Complete data were obtained in 81% of eligible ActiGraph participants and 72% of FitBit participants. PAH participants demonstrated fewer steps, lower vector magnitude counts per minute, more sedentary activity, and less intense physical activity at all levels compared with control participants. No statistically significant differences in heart rate variability were demonstrated between the 2 groups., Conclusions: Measurement of physical activity and other end points using wearable actigraphy devices was feasible in young children with PAH. Larger studies should determine associations between physical activity and disease severity in young patients with PAH to identify relevant end points for pediatric clinical trials., Competing Interests: Declaration of Competing Interest Funding for the study was provided by the Department of Health and Human Services/Food and Drug Administration BAA-18-00 123, University of Colorado. The authors declare no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Pulmonary hypertension (PH) is a significant health problem that contributes to high morbidity and mortality in diverse cardiac, pulmonary, and systemic diseases in children. Evidence-based advances in PH care have been challenged by a paucity of quality endpoints for assessing clinical course and the lack of robust clinical trial data to guide pharmacologic therapies in children. While the landmark adult AMBITION trial demonstrated the benefit of up-front combination PH therapy with ambrisentan and tadalafil, it remains unknown whether upfront combination therapy leads to more rapid and sustained clinical benefits in children with various categories of PH. In this article, we describe the inception of the Kids Mod PAH Trial, a multicenter Phase III trial, to address whether upfront combination therapy (sildenafil and bosentan vs. sildenafil alone) improves PH outcomes in children, recognizing that marked differences between the etiology and therapeutic response between adults and children exist. The primary endpoint of this study is WHO functional class (FC) 12 months after initiation of study drug therapy. In addition to the primary outcome, secondary endpoints are being assessed, including a composite measure of time to clinical worsening, WHO FC at 24 months, echocardiographic assessment of PH and quantitative assessment of right ventricular function, 6-min walk distance, and NT-proBNP levels. Exploratory endpoints include selected biomarkers, actigraphy, and assessments of quality of life. This study is designed to pave the way for additional clinical trials by establishing a robust infrastructure through the development of a PPHNet Clinical Trials Network., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Pulmonary Circulation published by Wiley Periodicals LLC on behalf of the Pulmonary Vascular Research Institute.)

Topic Importance: Postacute sequelae of SARS-CoV-2 (PASC) is a long-term consequence of acute infection from COVID-19. Clinical overlap between PASC and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has been observed, with shared symptoms including intractable fatigue, postexertional malaise, and orthostatic intolerance. The mechanistic underpinnings of such symptoms are poorly understood., Review Findings: Early studies suggest deconditioning as the primary explanation for exertional intolerance in PASC. Cardiopulmonary exercise testing reveals perturbations related to systemic blood flow and ventilatory control associated with acute exercise intolerance in PASC, which are not typical of simple detraining. Hemodynamic and gas exchange derangements in PASC have substantial overlap with those observed with ME/CFS, suggestive of shared mechanisms., Summary: This review illustrates exercise pathophysiologic commonalities between PASC and ME/CFS that will help guide future diagnostics and treatment., (Copyright © 2023 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Objectives: Congenital diaphragmatic hernia (CDH) is a birth defect associated with long-term morbidity. Our objective was to examine longitudinal change in Functional Status Scale (FSS) after hospital discharge in CDH survivors., Design: Single-center retrospective cohort study., Setting: Center for comprehensive CDH management at a quaternary, free-standing children's hospital., Patients: Infants with Bochdalek CDH were admitted to the ICU between January 2009 and December 2019 and survived until hospital discharge., Interventions: None., Measurements and Main Results: One hundred forty-two infants (58% male, mean birth weight 3.08 kg, 80% left-sided defects) met inclusion criteria. Relevant clinical data were extracted from the medical record to calculate FSS (primary outcome) at hospital discharge and three subsequent outpatient follow-up time points. The median (interquartile range [IQR]) FSS score at hospital discharge was 8.0 (7.0-9.0); 39 patients (27.5%) had at least moderate impairment (FSS ≥ 9). Median (IQR) FSS at 0- to 6-month ( n = 141), 6- to 12-month ( n = 141), and over 12-month ( n = 140) follow-up visits were 7.0 (7.0-8.0), 7.0 (6.0-8.0), and 6.0 (6.0-7.0), respectively. Twenty-one patients (15%) had at least moderate impairment at over 12-month follow-up; median composite FSS scores in the over 12-month time point decreased by 2.0 points from hospital discharge. Median feeding domain scores improved by 1.0 (1.0-2.0), whereas other domain scores remained without impairment. Multivariable analysis demonstrated right-sided, C- or D-size defects, extracorporeal membrane oxygenation use, cardiopulmonary resuscitation, and chromosomal anomalies were associated with impairment., Conclusions: The majority of CDH survivors at our center had mild functional status impairment (FSS ≤ 8) at discharge and 1-year follow-up; however, nearly 15% of patients had moderate impairment during this time period. The feeding domain had the highest level of functional impairment. We observed unchanged or improving functional status longitudinally over 1-year follow-up after hospital discharge. Longitudinal outcomes will guide interdisciplinary management strategies in CDH survivors., Competing Interests: Dr. Bechard’s institution received funding from the Academy of Nutrition and Dietetics, Pediatric Nutrition Practice Group. Dr. Mullen received funding from Altavant Sciences—Pediatric Pulmonary Hypertension Advisory Board and UpToDate. Dr. Mehta’s institution received funding from McGraw-Hill and Wolters Kluwer. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.)

Objective: To assess the extent and resolution of pulmonary hypertension (PH), cardiovascular factors, and echocardiographic findings associated with mortality in infants and children with vein of Galen malformation (VOGM)., Study Design: We performed a retrospective review of 49 consecutive children with VOGM admitted to Boston Children's Hospital from 2007 to 2020. Patient characteristics, echocardiographic data, and hospital course were analyzed for 2 cohorts based on age at presentation to Boston Children's Hospital: group 1 (age ≤60 days) or group 2 (age >60 days)., Results: Overall hospital survival was 35 of 49 (71.4%); 13 of 26 (50%) in group 1 and 22 of 23 (96%) in group 2 (P < .001). High-output PH (P = .01), cardiomegaly (P = .011), intubation (P = .019), and dopamine use (P = .01) were significantly more common in group 1 than group 2. Among patients in group 1, congestive heart failure (P = .015), intubation (P < .001), use of inhaled nitric oxide (P = .015) or prostaglandin E1 (P = .030), suprasystemic PH (P = .003), and right-sided dilation were significantly associated with mortality; in contrast, left ventricular volume and function, structural congenital heart disease, and supraventricular tachycardia were not associated. Inhaled nitric oxide achieved no clinical benefit in 9 of 11 treated patients. Resolution of PH was associated with overall survival (P < .001)., Conclusions: VOGM remains associated with substantial mortality among infants presenting at ≤60 days of life owing to factors associated with high output PH. Resolution of PH is an indicator associated with survival and a surrogate end point for benchmarking outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Over the past decade, recognition of the profound impact of the TBX4 ( T-box 4 ) gene, which encodes a member of the evolutionarily conserved family of T-box-containing transcription factors, on respiratory diseases has emerged. The developmental importance of TBX4 is emphasized by the association of TBX4 variants with congenital disorders involving respiratory and skeletal structures; however, the exact role of TBX4 in human development remains incompletely understood. Here, we discuss the developmental, tissue-specific, and pathological TBX4 functions identified through human and animal studies and review the published TBX4 variants resulting in variable disease phenotypes. We also outline future research directions to fill the gaps in our understanding of TBX4 function and of how TBX4 disruption affects development.

A male infant presented at term with neonatal respiratory failure and pulmonary hypertension. His respiratory symptoms improved initially, but he exhibited a biphasic clinical course, re-presenting at 15 months of age with tachypnea, interstitial lung disease, and progressive pulmonary hypertension. We identified an intronic TBX4 gene variant in close proximity to the canonical donor splice site of exon 3 (hg 19; chr17:59543302; c.401 + 3 A > T), also carried by his father who had a typical TBX4-associated skeletal phenotype and mild pulmonary hypertension, and by his deceased sister who died shortly after birth of acinar dysplasia. Analysis of patient-derived cells demonstrated a significant reduction in TBX4 expression resulting from this intronic variant. Our study illustrates the variable expressivity in cardiopulmonary phenotype conferred by TBX4 mutation and the utility of genetic diagnostics in enabling accurate identification and classification of more subtly affected family members., (© 2023. The Author(s).)

Objective: To characterize distinct comorbidities, outcomes, and treatment patterns in children with Down syndrome and pulmonary hypertension in a large, multicenter pediatric pulmonary hypertension registry., Study Design: We analyzed data from the Pediatric Pulmonary Hypertension Network (PPHNet) Registry, comparing demographic and clinical characteristics of children with Down syndrome and children without Down syndrome. We examined factors associated with pulmonary hypertension resolution and a composite outcome of pulmonary hypertension severity in the cohort with Down syndrome., Results: Of 1475 pediatric patients with pulmonary hypertension, 158 (11%) had Down syndrome. The median age at diagnosis of pulmonary hypertension in patients with Down syndrome was 0.49 year (IQR, 0.21-1.77 years), similar to that in patients without Down syndrome. There was no difference in rates of cardiac catheterization and prescribed pulmonary hypertension medications in children with Down syndrome and those without Down syndrome. Comorbidities in Down syndrome included congenital heart disease (95%; repaired in 68%), sleep apnea (56%), prematurity (49%), recurrent respiratory exacerbations (35%), gastroesophageal reflux (38%), and aspiration (31%). Pulmonary hypertension resolved in 43% after 3 years, associated with a diagnosis of pulmonary hypertension at age <6 months (54% vs 29%; P = .002) and a pretricuspid shunt (65% vs 38%; P = .02). Five-year transplantation-free survival was 88% (95% CI, 80%-97%). Tracheostomy (hazard ratio [HR], 3.29; 95% CI, 1.61-6.69) and reflux medication use (HR, 2.08; 95% CI, 1.11-3.90) were independently associated with a composite outcome of severe pulmonary hypertension., Conclusions: Despite high rates of cardiac and respiratory comorbidities that influence the severity of pulmonary hypertension, children with Down syndrome-associated pulmonary hypertension generally have a survival rate similar to that of children with non-Down syndrome-associated pulmonary hypertension. Resolution of pulmonary hypertension is common but reduced in children with complicated respiratory comorbidities., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Competing Interests: Dr. Vakili disclosed that he is an advisory board member of Novathena, Inc. and is a co-founder of ZEeST, Inc. Dr. Mullen received funding from Altavant Sciences Pediatric Advisory Board, UptoDate, and Actelion. The remaining authors have disclosed that they do not have any potential conflicts of interest.

Objectives: To describe epidemiology, interventions, outcomes, and the health services experience for a cohort of children with pulmonary hypertension (PH) who underwent tracheostomy placement and to identify risk factors for inhospital mortality and 30-day readmissions., Design: Retrospective cohort study of the Pediatric Health Information System database., Setting: Thirty-seven freestanding U.S. children's hospitals., Patients: Patients 31 days to 21 years old who were discharged from the hospital between January 1, 2009, and December 31, 2017, with a diagnosis of primary or secondary PH, and who underwent tracheostomy placement. Outcomes were examined over a 2-year period from the time of discharge from the index encounter., Interventions: None., Measurements and Main Results: There were 793 patients with PH who underwent tracheostomy placement. The overall inhospital mortality rate was 23.7%. Secondary PH due to congenital heart disease (CHD) was significantly associated with overall inhospital mortality (adjusted odds ratio [OR], 2.36; 95% CI, 1.38-4.04). The rate of 30-day readmissions for patients over the 2-year follow-up period was 33.3%. Tracheostomy during the index encounter and the diagnosis of secondary PH due to CHD were significantly associated with lower rates of 30-day readmissions (adjusted OR, 0.34; 95% CI, 0.19-0.61; and adjusted OR, 0.43; 95% CI, 0.24-0.77, respectively)., Conclusions: In the context of expanding utilization of tracheostomy and long-term ventilation, children with PH are among the highest risk cohorts for extended and repeated hospitalization and death. Tracheostomy placement during the index encounter was associated with fewer 30-day readmissions over the 2-year follow-up period. Further understanding of which subgroups may benefit from earlier intervention and which subgroups are at highest risk may offer important clinical insight when considering optimal timing of tracheostomy and may enhance informed decision-making for all stakeholders., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2022 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.)

Chronic pulmonary hypertension of infancy (cPHi) is a heterogeneous disease process that contributes to morbidity and mortality in preterm infants. cPHi is most commonly associated with chronic lung disease of prematurity and represents a unique phenotype of bronchopulmonary dysplasia. It is characterized by persistently elevated or newly rising pulmonary vascular resistance and pulmonary artery pressure beyond the first weeks of age. The high-pressure afterload on the right ventricle may or may not be tolerated, depending upon additional cardiovascular shunting and co-morbidities. A comprehensive clinical evaluation combined with advanced hemodynamic assessment by echocardiography and other cardiac imaging modalities help decipher the etiopathologies of disease, identify cardiopulmonary compromise earlier and guide individualized therapeutic intervention tailored by the phenotype. This review summarizes the underlying etiologies, risk factors for development, hemodynamic assessment, management, and follow-up of cPHi in preterm infants. We offer an algorithm for early detection of cPHi and outline research priorities., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: To characterize the prevalence, associations, management, and outcomes of supraventricular tachycardia (SVT) in neonates with congenital diaphragmatic hernia (CDH)., Design: Retrospective chart and cardiology code review within a cohort of patients with CDH was used to define a subpopulation with atrial arrhythmia. SVT mechanisms were confirmed by electrocardiogram analysis. Cox proportional hazard regression identified risk factors for SVT and association with clinical outcomes., Setting: Medical Surgical ICU in a single, tertiary center, Boston Children's Hospital., Patients: Eligible patients included neonates presenting with classic Bochdalek posterolateral CDH between 2005 and 2017, excluding newborns with Morgagni hernia or late diagnoses of CDH (>28 d)., Interventions: None., Measurements and Main Results: SVT arose in 25 of 232 neonates with CDH, (11%); 14 of 25 infants (56%) had recurrent SVT; atrioventricular node-dependent tachycardia was the most frequent mechanism (32%). The majority (71%) of SVT episodes received intervention. Nine patients (36%) received preventative antiarrhythmic medications. SVT was associated with lower Apgar score at 1 min, structural heart disease, larger defect size, extracorporeal membrane oxygenation (ECMO) support, and prostaglandin therapy for ductal patency as well as hospital stay greater than or equal to 8 weeks and use of supplemental oxygen at discharge., Conclusions: SVT can occur in neonates with CDH and frequently requires treatment. Odds of occurrence are increased with greater CDH disease severity, ECMO, and prostaglandin use. In unadjusted logistic regression analysis, SVT was associated with adverse hospital outcomes, underscoring the importance of recognition and management in this vulnerable population., Competing Interests: Dr. Dao received support for article research from the National Institutes of Health. Dr. Alexander disclosed the off-label product use of pediatric antiarrhythmia therapy and, in particular, infant antiarrhythmia therapy. Dr. Zalieckas received funding from Takeda Pharmaceutical. Dr. Mullen disclosed the off-label product use of Procainamide, Flecainide, Propranolol, Amiodarone, and Esmolol in pediatric age range. Dr. Mullen received funding from Altavant Sciences Pediatric for PAH Scientific Advisory Board and from Up to Date. Dr. Alexander received funding from Up to Date. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2022 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.)

While care models adapt to the COVID-19 pandemic with virtual and hybrid visits, clinical factors associated with treatment changes among ambulatory pediatric pulmonary arterial hypertension (PAH) patients are not well characterized. To understand which data critically altered treatment recommendations, we conducted a retrospective review among ambulatory children with Group 1 PAH to determine optimal visit and diagnostic strategies. Changes in management included: unplanned new treatments, dose modifications of vasodilators or diuretics, unscheduled hospitalizations, or changes to activity recommendations, catheterization schedule, or other testing. Factors prompting management changes were classified as symptoms, exam findings, or diagnostic tests. Across 398 ambulatory visits by 48 patients, 38 patients (79%) at 88 visits (22%) required change in management, most commonly in targeted PH medication. Changes were driven by symptoms alone (15%), diagnostic testing alone (47%), exam only (2%), symptoms and exam (2%), combination of testing and symptoms or testing and exam (25%), and other reasons (9%). Patients with World Health Organization functional Class IV (odds ratio [OR] 9.04 vs. Class I, p  = 0.014) or Class III (OR 2.08 vs. Class I, p  = 0.050) were more likely to undergo change in management. However, among Class I patients, 18% of visits generated changes in management because of test findings. While multiple factors affect management in ambulatory pediatric PH, neither symptoms nor exam was sufficient for identifying patients warranting clinical change in management. Testing accounted for most changes. Thus, in-person or hybrid surveillance including history, exam, and diagnostic testing remains essential for optimal management of pediatric PAH., Competing Interests: Dr. M. P. Mullen reports Altavant Sciences and Actelion scientific advisory board participation, outside the content of the manuscript. The remaining authors declare no conflict of interest., (© 2022 The Authors. Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Rationale: Hemodynamic assessments direct care among children with pulmonary hypertension, yet the use of cardiac catheterization is highly variable, which could impact patient care and research. Objectives: We analyzed hemodynamic findings from right heart catheterization (RHC) and left heart catheterization and acute vasodilator testing (AVT) and the safety of catheterization in children with World Symposium on Pulmonary Hypertension (WSPH) group 1 and 3 subtypes in a large multicenter North American cohort. Methods: Of 1,475 children enrolled in the Pediatric Pulmonary Hypertension Network Registry (2014-2020), there were 1,383 group 1 and 3 patients, of whom 671 (48.5%) underwent RHC at diagnosis and were included for analysis. Results: Compared with those without diagnostic RHC, these children were older, less likely to be an infant or preterm, more often female, treated with targeted pulmonary hypertension medications at diagnosis, and had advanced World Health Organization functional class. Catheterization was performed without a difference in complication rates between WSPH groups. Pulmonary capillary wedge pressure was well correlated with left ventricular end-diastolic pressure and left atrial pressures. Results of AVT using three different methods were comparable; positive AVT results were observed in 8.0-11.8% of subjects, did not differ between WSPH groups 1 and 3, and were not associated with freedom from the composite endpoint of lung transplantation or death during follow-up. Conclusions: In a large pediatric pulmonary hypertension cohort, diagnostic RHC with or without left heart catheterization in WSPH group 1 and 3 patients was performed safely at experienced pediatric pulmonary hypertension centers. Hemodynamic differences were noted between group 1 and 3 subjects. Higher mean pulmonary arterial pressure and mean pulmonary arterial pressure/mean systemic arterial pressure ratio were associated with a higher risk of death/transplantation. Findings suggest overall safety and potential value of RHC as a standard diagnostic approach to guide pulmonary hypertension management in children.

Background: Lung transplantation is a therapeutic option for end-stage pediatric pulmonary hypertension (PH). Right ventricular (RV) recovery post-lung transplant in children with PH has not been well-described, and questions persist about the peri-operative course and post-transplant cardiac function after lung transplantation in medically refractory PH patients with baseline RV dysfunction., Methods: A single-center chart review identified patients with childhood PH who subsequently underwent bilateral orthotopic lung transplantation between 2000 and 2020. Twenty-six patients met criteria; three were excluded due to echocardiograms not available for digital review. RV fractional area change (FAC) and left ventricular eccentricity index (LVEI) were determined prior to transplantation, and at 1, 3, 6, and 12-month post-transplantation., Results: Fourteen of 23 patients had baseline RV dysfunction. The median age at transplantation was 16.5 years and 13.9 years for those with and without baseline RV dysfunction, respectively. Of the 14 with baseline RV dysfunction, 12 (86%) were alive 1-year post-transplantation. All patients with baseline RV dysfunction had increased RV-FAC post-transplantation with normalization of RV-FAC in 70% at 3 months and 100% of patients by 12-month post-transplantation. Duration of ventilation (p = .4), intensive care unit (p = .5), or hospital stay (p = .9) was not associated with pre-transplant RV function., Conclusions: Among pediatric patients with PH and RV dysfunction, pre-transplantation RV function was not associated with short-term outcomes. All patients with baseline RV dysfunction had improvement in RV function, justifying consideration of lung transplantation among pediatric patients with end-stage PH and RV dysfunction., (© 2022 Wiley Periodicals LLC.)

Competing Interests: Conflict of interest: S.H. Abman has nothing to disclose. Conflict of interest: M.P. Mullen reports grants from the National Heart, Lung, and Blood Institute, during the conduct of the study; personal fees from Actelion, outside the submitted work. Conflict of interest: L.A. Sleeper reports grants from the National Heart, Lung, and Blood Institute (subcontract from University of Colorado), during the conduct of the study. Conflict of interest: E.D. Austin has nothing to disclose. Conflict of interest: E.B. Rosenzweig reports grants from the National Institutes of Health, during the conduct of the study. Conflict of interest: J.P. Kinsella has nothing to disclose. Conflict of interest: The University of Colorado contracts with Actelion, Bayer, Gilead and United Therapeutics for D. Ivy to be a consultant and preform clinical research trials. Conflict of interest: R.K. Hopper has nothing to disclose. Conflict of interest: J.U. Raj has nothing to disclose. Conflict of interest: J. Fineman has nothing to disclose. Conflict of interest: R.L. Keller reports grants from the National Heart, Lung, and Blood Institute, during the conduct of the study. Conflict of interest: A. Bates has nothing to disclose. Conflict of interest: U.S. Krishnan has nothing to disclose. Conflict of interest: C.M. Avitabile has nothing to disclose. Conflict of interest: A. Davidson has nothing to disclose. Conflict of interest: M.D. Natter reports grants from the National Heart, Lung, and Blood Institute, during the conduct of the study. Conflict of interest: K.D. Mandl reports no specific conflicts, however in the interest of full disclosure, reports personal fees from Merck, and philanthropy from Eli Lily to his lab, during the conduct of the study.

ARHGAP42 encodes Rho GTPase activating protein 42 that belongs to a member of the GTPase Regulator Associated with Focal Adhesion Kinase (GRAF) family. ARHGAP42 is involved in blood pressure control by regulating vascular tone. Despite these findings, disorders of human variants in the coding part of ARHGAP42 have not been reported. Here, we describe an 8-year-old girl with childhood interstitial lung disease (chILD), systemic hypertension, and immunological findings who carries a homozygous stop-gain variant (c.469G>T, p.(Glu157Ter)) in the ARHGAP42 gene. The family history is notable for both parents with hypertension. Histopathological examination of the proband lung biopsy showed increased mural smooth muscle in small airways and alveolar septa, and concentric medial hypertrophy in pulmonary arteries. ARHGAP42 stop-gain variant in the proband leads to exon 5 skipping, and reduced ARHGAP42 levels, which was associated with enhanced RhoA and Cdc42 expression. This is the first report linking a homozygous stop-gain variant in ARHGAP42 with a chILD disorder, systemic hypertension, and immunological findings in human patient. Evidence of smooth muscle hypertrophy on lung biopsy and an increase in RhoA/ROCK signaling in patient cells suggests the potential mechanistic link between ARHGAP42 deficiency and the development of chILD disorder., Competing Interests: The authors have declared that no competing interests exist.

Background: Bovine TB (bTB), caused by infection with Mycobacterium bovis, is a major endemic disease affecting global cattle production. The key innate immune cell that first encounters the pathogen is the alveolar macrophage, previously shown to be substantially reprogrammed during intracellular infection by the pathogen. Here we use differential expression, and correlation- and interaction-based network approaches to analyse the host response to infection with M. bovis at the transcriptome level to identify core infection response pathways and gene modules. These outputs were then integrated with genome-wide association study (GWAS) data sets to enhance detection of genomic variants for susceptibility/resistance to M. bovis infection., Results: The host gene expression data consisted of RNA-seq data from bovine alveolar macrophages (bAM) infected with M. bovis at 24 and 48 h post-infection (hpi) compared to non-infected control bAM. These RNA-seq data were analysed using three distinct computational pipelines to produce six separate gene sets: 1) DE genes filtered using stringent fold-change and P-value thresholds (DEG-24: 378 genes, DEG-48: 390 genes); 2) genes obtained from expression correlation networks (CON-24: 460 genes, CON-48: 416 genes); and 3) genes obtained from differential expression networks (DEN-24: 339 genes, DEN-48: 495 genes). These six gene sets were integrated with three bTB breed GWAS data sets by employing a new genomics data integration tool-gwinteR. Using GWAS summary statistics, this methodology enabled detection of 36, 102 and 921 prioritised SNPs for Charolais, Limousin and Holstein-Friesian, respectively., Conclusions: The results from the three parallel analyses showed that the three computational approaches could identify genes significantly enriched for SNPs associated with susceptibility/resistance to M. bovis infection. Results indicate distinct and significant overlap in SNP discovery, demonstrating that network-based integration of biologically relevant transcriptomics data can leverage substantial additional information from GWAS data sets. These analyses also demonstrated significant differences among breeds, with the Holstein-Friesian breed GWAS proving most useful for prioritising SNPS through data integration. Because the functional genomics data were generated using bAM from this population, this suggests that the genomic architecture of bTB resilience traits may be more breed-specific than previously assumed.

We performed a retrospective study of coronavirus disease 2019 (COVID-19) in people with human immunodeficiency virus (PWH). PWH with COVID-19 demonstrated severe lymphopenia and decreased CD4+ T cell counts. Levels of inflammatory markers, including C-reactive protein, fibrinogen, D-dimer, interleukin 6, interleukin 8, and tumor necrosis factor α were commonly elevated. In all, 19 of 72 hospitalized individuals (26.4%) died and 53 (73.6%) recovered. PWH who died had higher levels of inflammatory markers and more severe lymphopenia than those who recovered. These findings suggest that PWH remain at risk for severe manifestations of COVID-19 despite antiretroviral therapy and that those with increased markers of inflammation and immune dysregulation are at risk for worse outcomes., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: The optimal oxygen saturation target in preterm infants is not known. In this study, we aimed to assess the effect of lower oxygen saturation targets on the rate of bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), and pulmonary hypertension (PH) in preterm infants., Methods: Retrospective cohort study comparing BPD, ROP, and PH incidence among two cohorts of infants born at≤32 weeks gestation with different oxygen saturation targets at≥34 weeks post-menstrual age (PMA): cohort 1, 94-98% (n = 126); cohort 2, 92-97% (n = 121). Groups compared by Chi-square test, t-test, and multivariable logistic regression., Results: When comparing cohort 1 (average gestational age 29.8 weeks, average birth weight 1271g) with cohort 2 (average gestational age 29.6 weeks, average birth weight 1299g), there was no difference in rate of BPD (24% vs. 19%, p = 0.38), ROP (4% vs. 3%, p = 0.49), or PH (2% vs. 4%, p = 0.44)., Conclusion: An oxygen saturation target of 92-97% at≥34 weeks PMA was not associated with a higher rate of PH or lower rate of BPD or ROP when compared with a higher target of 94-98%.

For pediatric pulmonary arterial hypertension (PAH) patients treated with parenteral prostanoids, response predictors, and the dose-effect relationship are ill defined. We determined the following: (1) which pulmonary vascular hemodynamic variable, after initiating prostanoids, best correlates with a significant clinical response; (2) the time interval after treatment when if no pulmonary hemodynamic improvement has occurred, none is ever likely to; and (3) the relationship between the prostanoid dose and its hemodynamic effects. This is a retrospective cohort study of 31 pediatric patients with Group 1 PAH treated with parenteral prostanoids. We found the following: (1) A fall in mean pulmonary arterial pressure (mPAP) of ≥25% predicted freedom from adverse clinical events with 80.7% accuracy and was also associated with improved functional class. (2) Thirty-three percent of patients who avoided an adverse clinical event demonstrated a ≥25% reduction in mPAP after 1 year of treatment, and 65% by 2 years. (3) Lower mPAP was seldom seen with doses of epoprostenol >60 ng/kg/min (100 ng/kg/min for treprostinil). Cardiac index was positively correlated with the dose of epoprostenol but not treprostinil; cardiac index >4 l/min/m 2 was seen at modest as well as high doses. We conclude that a ≥25% fall in mPAP on prostanoids indicates a positive clinical response which, if validated in other studies, may be useful for patient management or clinical trials. Some patients take more than 2 years for this change. Exceptionally high doses were generally not more effective than lower, although we could not determine whether lower doses would have been as effective., (© The Author(s) 2020.)

Background Long-term survival in patients with truncus arteriosus is favorable, but there remains significant morbidity associated with ongoing reinterventions. We aimed to study the long-term outcomes of the truncal valve and identify risk factors associated with truncal valve intervention. Methods and Results We retrospectively reviewed patients who underwent initial truncus arteriosus repair at our institution from 1985 to 2016. Analysis was performed on the 148 patients who were discharged from the hospital and survived ≥30 days postoperatively using multivariable competing risks Cox regression modeling. Median follow-up time was 12.6 years (interquartile range, 5.0-22.1 years) after discharge from full repair. Thirty patients (20%) underwent at least one intervention on the truncal valve during follow-up. Survival at 1, 10, and 20 years was 93.1%, 87.0%, and 80.9%, respectively. The cumulative incidence of any truncal valve intervention by 20 years was 25.6%. Independent risk factors for truncal valve intervention included moderate or greater truncal valve regurgitation (hazard ratio [HR], 4.77; P <0.001) or stenosis (HR, 4.12; P <0.001) before full truncus arteriosus repair and moderate or greater truncal valve regurgitation at discharge after full repair (HR, 8.60; P <0.001). During follow-up, 33 of 134 patients (25%) progressed to moderate or greater truncal valve regurgitation. A larger truncal valve root z -score before truncus arteriosus full repair and during follow-up was associated with worsening truncal valve regurgitation. Conclusions Long-term rates of truncal valve intervention are significant. At least moderate initial truncal valve stenosis and initial or residual regurgitation are independent risk factors associated with truncal valve intervention. Larger truncal valve root z -score is associated with significant truncal valve regurgitation and may identify a subset of patients at risk for truncal valve dysfunction over time.

As part of a clinical trial, this study examined the pharmacokinetics (PK) of oral treprostinil (TRE) in children with pulmonary arterial hypertension. The trial consisted of the following 3 cohorts: transition from parenteral (cohort 1) or inhaled (cohort 2) TRE, or de novo addition (cohort 3). Oral TRE was dosed 3 times daily. PK samples were obtained before an oral TRE dose, and at 2, 4, 6, and 8 hours thereafter. The PK parameters were calculated using noncompartmental analysis. Thirty-two children (n = 10 in cohorts 1 and 2, n = 12 in cohort 3) were enrolled; the median age was 12 years (range 7-17 years), and the median weight was 42.2 kg (range 19.3-78 kg). The median oral TRE dose for all subjects was 3.8 mg (5.9, 3.5, and 4.0 mg for cohorts 1, 2, and 3, respectively). The TRE concentration versus time profile demonstrated a peak concentration at a median of 3.8 hours with wide variability. In cohort 1, oral dosing led to higher peak (5.9 ng/mL) and lower trough (1 ng/mL) concentrations than parenteral (peak 5.4 ng/mL and trough 4.2 ng/mL), but a lower mean concentration (3.61 vs. 4.46 ng/mL), likely due to variable metabolism and noncomparable dosing. Both the area under the curve and average concentration were linearly correlated with oral TRE dose and dose normalized to body weight, but not with weight or age alone. In pediatric patients, an increased oral TRE dose or dose frequency may be required to minimize PK variability and achieve greater correlation with parenteral dosing.

Objective: To determine the natural history of pulmonary function for survivors of congenital diaphragmatic hernia (CDH)., Study Design: This was a retrospective cohort study of survivors of CDH born during 1991-2016 and followed at our institution. A generalized linear model was fitted to assess the longitudinal trends of ventilation (V), perfusion (Q), and V/Q mismatch. The association between V/Q ratio and body mass index percentile as well as functional status was also assessed with a generalized linear model., Results: During the study period, 212 patients had at least one V/Q study. The average ipsilateral V/Q of the cohort increased over time (P < .01), an effect driven by progressive reduction in relative perfusion (P = .012). A higher V/Q ratio was correlated with lower body mass index percentile (P < .001) and higher probability of poor functional status (New York Heart Association class III or IV) (P = .045)., Conclusions: In this cohort of survivors of CDH with more severe disease characteristics, V/Q mismatch worsens over time, primarily because of progressive perfusion deficit of the ipsilateral side. V/Q scans may be useful in identifying patients with CDH who are at risk for poor growth and functional status., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Bovine tuberculosis is caused by infection with Mycobacterium bovis , which can also cause disease in a range of other mammals, including humans. Alveolar macrophages are the key immune effector cells that first encounter M. bovis and how the macrophage epigenome responds to mycobacterial pathogens is currently not well understood. Here, we have used chromatin immunoprecipitation sequencing (ChIP-seq), RNA-seq and miRNA-seq to examine the effect of M. bovis infection on the bovine alveolar macrophage (bAM) epigenome. We show that H3K4me3 is more prevalent, at a genome-wide level, in chromatin from M. bovis -infected bAM compared to control non-infected bAM; this was particularly evident at the transcriptional start sites of genes that determine programmed macrophage responses to mycobacterial infection (e.g. M1/M2 macrophage polarisation). This pattern was also supported by the distribution of RNA Polymerase II (Pol II) ChIP-seq results, which highlighted significantly increased transcriptional activity at genes demarcated by permissive chromatin. Identification of these genes enabled integration of high-density genome-wide association study (GWAS) data, which revealed genomic regions associated with resilience to infection with M. bovis in cattle. Through integration of these data, we show that bAM transcriptional reprogramming occurs through differential distribution of H3K4me3 and Pol II at key immune genes. Furthermore, this subset of genes can be used to prioritise genomic variants from a relevant GWAS data set., (Copyright © 2020 Hall, Vernimmen, Browne, Mullen, Gordon, MacHugh and O’Doherty.)

Objective: Real-world data (RWD) are increasingly used for pharmacoepidemiology and regulatory innovation. Our objective was to compare adverse drug event (ADE) rates determined from two RWD sources, electronic health records and administrative claims data, among children treated with drugs for pulmonary hypertension., Materials and Methods: Textual mentions of medications and signs/symptoms that may represent ADEs were identified in clinical notes using natural language processing. Diagnostic codes for the same signs/symptoms were identified in our electronic data warehouse for the patients with textual evidence of taking pulmonary hypertension-targeted drugs. We compared rates of ADEs identified in clinical notes to those identified from diagnostic code data. In addition, we compared putative ADE rates from clinical notes to those from a healthcare claims dataset from a large, national insurer., Results: Analysis of clinical notes identified up to 7-fold higher ADE rates than those ascertained from diagnostic codes. However, certain ADEs (eg, hearing loss) were more often identified in diagnostic code data. Similar results were found when ADE rates ascertained from clinical notes and national claims data were compared., Discussion: While administrative claims and clinical notes are both increasingly used for RWD-based pharmacovigilance, ADE rates substantially differ depending on data source., Conclusion: Pharmacovigilance based on RWD may lead to discrepant results depending on the data source analyzed. Further work is needed to confirm the validity of identified ADEs, to distinguish them from disease effects, and to understand tradeoffs in sensitivity and specificity between data sources., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Medical Informatics Association.)

Background: Validated protocols for diagnostic testing and management of pregnant women with cardiovascular disease (CVD) do not exist. Our objective was to establish a prospective standardized protocol for the clinical evaluation of pregnant women with CVD., Methods: The Standardized Outcomes in Reproductive Cardiovascular Care (STORCC) initiative prospectively enrolled pregnant women with CVD into a standardized diagnostic testing and assessment protocol. Detailed cardiac and obstetric data were collected during the antepartum, intrapartum, and postpartum periods. Each woman was assigned a STORCC color code of perceived risk at a monthly multidisciplinary conference., Results: In 250 pregnancies of 207 women with CVD, the standardized care protocol was followed in 136 and routine care in 114. The median age of the subjects was 32 years, and the most common form of heart disease was congenital heart disease (77%). Women enrolled in standardized care protocol had high compliance with second- and third-trimester visits (93%) and postpartum visits (76%). Maternal cardiac complications occurred in 10%. The STORCC cardiac and obstetric color codes predicted adverse outcomes within each respective category (P = .02, .01)., Conclusions: The STORCC protocol for prospective diagnostic testing and follow-up of pregnant women with CVD was successfully established, and compliance was high. The strength of a standardized testing and care protocol as well as detailed classification of labor and delivery characteristics allows for robust analyses into specific questions regarding testing protocols, and mode and timing of delivery., (Copyright © 2019. Published by Elsevier Inc.)

The Galway sheep population is the only native Irish sheep breed and this livestock genetic resource is currently categorised as 'at-risk'. In the present study, comparative population genomics analyses of Galway sheep and other sheep populations of European origin were used to investigate the microevolution and recent genetic history of the breed. These analyses support the hypothesis that British Leicester sheep were used in the formation of the Galway. When compared to conventional and endangered breeds, the Galway breed was intermediate in effective population size, genomic inbreeding and runs of homozygosity. This indicates that, although the Galway breed is declining, it is still relatively genetically diverse and that conservation and management plans informed by genomic information may aid its recovery. The Galway breed also exhibited distinct genomic signatures of artificial or natural selection when compared to other breeds, which highlighted candidate genes that may be involved in production and health traits., (Copyright © 2019 McHugo, Browett, Randhawa, Howard, Mullen, Richardson, Park, Magee, Scraggs, Dover, Correia, Hanrahan and MacHugh.)

Rare variants in the T-box transcription factor 4 gene ( TBX4 ) have recently been recognised as an emerging cause of paediatric pulmonary hypertension (PH). Their pathophysiology and contribution to persistent pulmonary hypertension in neonates (PPHN) are unknown. We sought to define the spectrum of clinical manifestations and histopathology associated with TBX4 variants in neonates and children with PH.We assessed clinical data and lung tissue in 19 children with PH, including PPHN, carrying TBX4 rare variants identified by next-generation sequencing and copy number variation arrays.Variants included six 17q23 deletions encompassing the entire TBX4 locus and neighbouring genes, and 12 likely damaging mutations. 10 infants presented with neonatal hypoxic respiratory failure and PPHN, and were subsequently discharged home. PH was diagnosed later in infancy or childhood. Three children died and two required lung transplantation. Associated anomalies included patent ductus arteriosus, septal defects, foot anomalies and developmental disability, the latter with a higher prevalence in deletion carriers. Histology in seven infants showed abnormal distal lung development and pulmonary hypertensive remodelling. TBX4 mutations and 17q23 deletions underlie a new form of developmental lung disease manifesting with severe, often biphasic PH at birth and/or later in infancy and childhood, often associated with skeletal anomalies, cardiac defects, neurodevelopmental disability and other anomalies., Competing Interests: Conflict of interest: C. Galambos has nothing to disclose. Conflict of interest: M.P. Mullen has acted as a site principal investigator on trials sponsored by United Therapeutics, Actelion, Ikaria and GSK, and received travel support from Actelion, outside the submitted work. Conflict of interest: J.T. Shieh has nothing to disclose. Conflict of interest: N. Schwerk has nothing to disclose. Conflict of interest: M.J. Kielt has nothing to disclose. Conflict of interest: N. Ullmann has nothing to disclose. Conflict of interest: R. Boldrini has nothing to disclose. Conflict of interest: I. Stucin-Gantar has nothing to disclose. Conflict of interest: C. Haass has nothing to disclose. Conflict of interest: M. Bansal has nothing to disclose. Conflict of interest: P.B. Agrawal has nothing to disclose. Conflict of interest: J. Johnson has nothing to disclose. Conflict of interest: D. Peca has nothing to disclose. Conflict of interest: C. Surace has nothing to disclose. Conflict of interest: R. Cutrera has nothing to disclose. Conflict of interest: M.W. Pauciulo has nothing to disclose. Conflict of interest: W.C. Nichols has nothing to disclose. Conflict of interest: M. Griese has nothing to disclose. Conflict of interest: D. Ivy has contracts (through the University of Colorado School of Medicine) with Actelion, Bayer, Lilly and United Therapeutics for consultancy and research studies. Conflict of interest: S.H. Abman has nothing to disclose. Conflict of interest: E.D. Austin has nothing to disclose. Conflict of interest: O. Danhaive has nothing to disclose., (Copyright ©ERS 2019.)

Background: Pulmonary hypertension is a rare, life-threatening disease with limited therapeutic options and no definitive cure. Continuous intravenous prostacyclin therapy is indicated for treatment of severe disease. These medications have a narrow therapeutic index and a brief half-life; therefore, administration errors can be lethal., Objective: To reduce medication errors through an inpatient program to improve, standardize, and disseminate continuous intravenous prostacyclin therapy practice guidelines., Methods: Data were collected from the electronic safety reporting system of a single hospital to determine the number and types of continuous intravenous prostacyclin therapy errors that were reported over an 8-year period. A clinical database and hospital pharmacy records were used to determine the number of days on which hospitalized pediatric patients received the therapy., Interventions: A nursing-directed quality improvement initiative to enhance the safety of continuous intravenous prostacyclin therapy for pediatric patients was begun in January 2009. Efforts to improve safety fell into 4 domains: policy, process, education, and hospital-wide safety initiatives., Results: The number of therapy errors per 1000 patient days fell from 19.28 in 2009 to 5.95 in 2016. Chi-square analysis was used to compare the result for 2009 with that for each subsequent year, with P values of .66, .35, .16, .09, .03, .12, and .25 found for 2010 through 2016, respectively., Conclusions: The trend in reduction of continuous intravenous prostacyclin therapy errors suggests that proactive processes to standardize its administration, emphasizing both policy and education, reduce medication errors and increase patient safety., (©2019 American Association of Critical-Care Nurses.)

Objective: To investigate racial and ethnic differences in pulmonary hypertension subtypes and survival differences in a pediatric population., Study Design: This was a retrospective analysis of a cohort of patients with pulmonary hypertension (aged ≤18 years) enrolled in the Pediatric Pulmonary Hypertension Network registry between 2014 and 2018, comprising patients at eight Pediatric Centers throughout North America (n = 1417)., Results: Among children diagnosed after the neonatal period, pulmonary arterial hypertension was more prevalent among Asians (OR, 1.83; 95% CI, 1.21-2.79; P = .0045), lung disease-associated pulmonary hypertension among blacks (OR, 2.09; 95% CI, 1.48-2.95; P < .0001), idiopathic pulmonary arterial hypertension among whites (OR, 1.58; 95% CI, 1.06-2.41; P = .0289), and pulmonary veno-occlusive disease among Hispanics (OR, 6.11; 95% CI, 1.34-31.3; P = .0184). Among neonates, persistent pulmonary hypertension of the newborn (OR, 4.07; 95% CI, 1.54-10.0; P = .0029) and bronchopulmonary dysplasia (OR, 8.11; 95% CI, 3.28-19.8; P < .0001) were more prevalent among blacks, and congenital diaphragmatic hernia was more prevalent among whites (OR, 2.29; 95% CI, 1.25-4.18; P = .0070). An increased mortality risk was observed among blacks (HR, 1.99; 95% CI, 1.03-3.84; P = .0396), driven primarily by the heightened mortality risk among those with lung disease-associated pulmonary hypertension (HR, 2.84; 95% CI, 1.15-7.04; P = .0241)., Conclusions: We found significant racial variability in the prevalence of pulmonary hypertension subtypes and survival outcomes among children with pulmonary hypertension. Given the substantial burden of this disease, further studies to validate phenotypic differences and to understand the underlying causes of survival disparities between racial and ethnic groups are warranted., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Treprostinil, a prostacyclin analogue, is approved for the treatment of pulmonary arterial hypertension (PAH) in adults. Transition from parenteral to oral treprostinil has been successfully accomplished in adults with PAH but not in children. In this multicenter study, pediatric patients treated with parenteral (Cohort 1) or inhaled (Cohort 2) treprostinil were transitioned to oral treprostinil. Prostacyclin-naïve individuals on background oral PAH therapy received oral treprostinil as add-on therapy (Cohort 3). Successful transition was oral treprostinil dose maintenance through week 24. Patients were monitored for adverse events (AEs), 6-min walk distance (6MWD), PAH symptoms, World Health Organization (WHO) Functional Class (FC), cardiac magnetic resonance imaging (cMRI), cardiopulmonary exercise testing (CPET), and quality of life through 24 weeks. A total of 32 patients were enrolled in the study; 23 (72%) were girls (mean age = 12.2 years). All patients were on background oral PAH therapy. Overall, patients (96.9%) maintained transition to oral treprostinil; one patient (Cohort 1) transitioned to oral treprostinil, then back to parenteral after experiencing syncope and WHO FC change from II to III. Cohorts 1, 2, and 3 received a final mean oral treprostinil dose of 5.6, 3.3, and 4.5 mg t.i.d., respectively. All cohorts had variable changes in 6MWD, cMRI, and CPET. Overall, 12 serious AEs were reported. All patients had drug-related AEs including headache (81%), diarrhea (69%), nausea (66%), vomiting (66%), and flushing (56%). Pediatric patients maintained transition to oral treprostinil with preservation of exercise capacity and WHO FC. Prostanoid-related AEs were most common and similar to those reported in adults.

Reports of "treat and repair" of cardiac shunting lesions with inoperably high pulmonary vascular resistance (PVR) mostly concern pre-tricuspid defects; post-tricuspid lesions are different. We report our experience with pulmonary artery (PA) banding ± targeted pulmonary hypertension medications in five patients with a large VSD and inoperably high PVR, and review previous reports of PA banding with post-tricuspid defects. Three of our 5 patients had mean PAP > 50 mmHg after banding and no or only a transient fall in PVR. Two patients had mean PAP < 50 mmHg and lower PVR after banding; they had closure of their VSDs but have since had a progressive increase in PVR (follow-up after closure, 3.5 and 7.7 years). Previous reports have also documented difficulty in achieving sufficient band gradient. Of previously reported patients, only one became operable only after banding and targeted therapy, and was repaired; follow-up after repair was short-term (16 months). Our and previous experience demonstrate the difficulty in placing a PA band sufficiently tight to substantially reduce PA pressure. Reported attempts to "treat and repair" post-tricuspid defects are few and have met with limited success, and we found that PVR may increase significantly over time after repair. But more information is needed. Accurate interpretation of experience with "treat and repair" requires: careful characterization of the pulmonary circulation prior to "treating"; considering spontaneously reversible factors at pre-treatment catheterization before ascribing reduction in PVR to medical therapy; and long-term observation of PVR in patients who have had defect closure.

Objectives: To compare registry and electronic health record (EHR) data mining approaches for cohort ascertainment in patients with pediatric pulmonary hypertension (PH) in an effort to overcome some of the limitations of registry enrollment alone in identifying patients with particular disease phenotypes., Study Design: This study was a single-center retrospective analysis of EHR and registry data at Boston Children's Hospital. The local Informatics for Integrating Biology and the Bedside (i2b2) data warehouse was queried for billing codes, prescriptions, and narrative data related to pediatric PH. Computable phenotype algorithms were developed by fitting penalized logistic regression models to a physician-annotated training set. Algorithms were applied to a candidate patient cohort, and performance was evaluated using a separate set of 136 records and 179 registry patients. We compared clinical and demographic characteristics of patients identified by computable phenotype and the registry., Results: The computable phenotype had an area under the receiver operating characteristics curve of 90% (95% CI, 85%-95%), a positive predictive value of 85% (95% CI, 77%-93%), and identified 413 patients (an additional 231%) with pediatric PH who were not enrolled in the registry. Patients identified by the computable phenotype were clinically distinct from registry patients, with a greater prevalence of diagnoses related to perinatal distress and left heart disease., Conclusions: Mining of EHRs using computable phenotypes identified a large cohort of patients not recruited using a classic registry. Fusion of EHR and registry data can improve cohort ascertainment for the study of rare diseases., Trial Registration: ClinicalTrials.gov: NCT02249923., (Copyright © 2017 Elsevier Inc. All rights reserved.)