Outcomes in Children With Idiopathic Pulmonary Arterial Hypertension

Direct prostacyclin transition in pediatric patients with pulmonary hypertension

Pediatric patients with pulmonary arterial hypertension (PAH) are commonly treated with the prostacyclin analog treprostinil in IV, SQ, inhaled or oral form, or the prostacyclin receptor agonist selexipag. Patients who transition between these medications often follow recommendations for gradual up- and down-titrations that take place over several days in the hospital or several weeks as an outpatient. However, hospital resources are limited, and long transitions are inconvenient for patients and families. We report a case series of eight pediatric patients with PAH transitioned directly between prostacyclins with no overlapping doses. Direct medication transitions occurred in the cardiac intensive care unit (CICU), at home and in cardiology clinic. Equivalent doses for selexipag were estimated using information extrapolated from experience, published materials and selexipag study guidelines. All patients completed direct transition as planned and remained on transition dose for at least 1 week. In most cases selexipag was up-titrated at home after establishing initial transition dose. In select patients, direct prostacyclin transition in pediatric patients with PAH is safe, effective, convenient for families and reduces the use of hospital resources.

Demographic, hemodynamic characteristics, and therapeutic trends of pulmonary hypertension patients: The Pulmonary Hypertension Mexican registry (REMEHIP)

Data on demographic characteristics and therapeutic approaches in Latin American pulmonary arterial hypertension (PAH) patients are scarce. Pulmonary Hypertension Mexican registry (REMEHIP) is a multicenter Mexican registry of adult and pediatric patients, including prevalent and incident cases. Objective: assess clinical characteristics, treatment trends, and in-hospital outcomes. Inclusion: age >2 years, diagnosis of pulmonary hypertension (PH) (groups 1 and 4), right heart catheterization with mPAP ≥25 mmHg, PWP ≤ 15 mmHg, and PVR > 3 Wood unit (WU). We included 875 PH patients, 619 adults, 133 pediatric idiopathic PAH (IPAH), and 123 chronic thromboembolic pulmonary hypertension (CTEPH) patients. We enrolled 48.4% of the incident and 51.6% of the prevalent adult and pediatric patients. PAH adults: age 43 ± 15, females 81.9%, functional class (FC) (I/II) 66.5%, 6-min walk distance (6MWD) 378 ± 112 m, mPAP 57.3 ± 19.0 mmHg, confidence interval (CI) 3.3 ± 1.5 L/min/m2, PVR 12.0 ± 8.1 WU. PAH pediatrics: age 9 ± 5, females 51.1%, FC (I/II) 85.5%, 6MWD 376 ± 103 m, mPAP 49.7 ± 13.4 mmHg, CI 2.6 ± 0.9 L/min/m2, PVR 16.4 ± 13.5 WU. CTEPH: age 44 ± 17, females 56.1%, FC (I/II) 65.5%, 6MWD 369 ± 126 m, mPAP 49.7 ± 13.4 mmHg, CI 2.6 ± 0.9 L/min/m2, PVR 10.5 + 6.5 WU. When we analyzed the IPAH group separately, it sustained a high functional class I/II incidence. REMEHIP shows better functional class in young females with severe PAH than in American and European patients. Also, PAH pediatric patients had a better functional class than other registries. However, our registry also shows that our population's access to specific pharmacologic treatments is still far from optimal.

Long-Term Effect of TBX4 Germline Mutation on Pulmonary Clinico-Histopathologic Phenotype

Tbx4 protein, expressed in mesenchyme of the developing lung, contributes to airway branching and distal lung growth. An association between pediatric onset of pulmonary arterial hypertension (PAH) and genetic variations coding for the T-box transcription factor 4 gene (TBX4) has been increasingly recognized. Tbx4-related PAH onset has a bimodal age distribution, including severe to lethal PAH in newborns and later onset PAH. We present an autopsy study of a 24-year-old male with a heterozygous TBX4 variant, who developed pulmonary arterial hypertension at age 12 years. This unique case highlights the complex pulmonary histopathology leading to lethal cardiopulmonary failure in the setting of TBX4 mutation.

Factors leading to supranormal cardiac index in pediatric pulmonary hypertension patients treated with parenteral prostanoid therapy

Parenteral prostanoid therapy (PPT) can result in supranormal cardiac index (SCI; >4 L/min/m²) in pediatric pulmonary hypertension (PPH) patients. We evaluated the incidence, hemodynamic factors, and outcomes associated with SCI in PPH. This retrospective cohort study included 22 PPH patients on PPT from 2005 to 2020. Hemodynamic profiles were compared between the baseline and 3-6 month follow-up catheterization in the SCI and non-SCI cohorts. Cox regression analysis examined time to composite adverse outcome (CAO; Potts shunt, lung transplant, or death) controlling for initial disease severity. SCI developed in 17 (77%) patients, of whom 11 (65%) developed SCI within 6 months. The SCI cohort was characterized by significant augmentation of cardiac index (CI) and stroke volume (SV) as well as reductions in systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR). Conversely, the non-SCI cohort had unchanged SV despite a modest rise in CI as well as persistent vasoconstriction. After median follow-up of 4.3 years (range 0.2-13 years), non-SCI patients were at significantly increased risk for the CAO (5/5: three deaths, two Potts shunts) compared with SCI patients (5/17: two deaths, three lung transplants; adjusted hazard ratio 14.0 [95% confidence interval: 2.1-91.3], p < 0.001). A majority of PPH patients developed SCI within 6-12 months of starting PPT and demonstrated lower risk of adverse outcomes compared with non-SCI patients. These data suggest that change in SVR and SV after 3-6 months of PPT may be early markers of therapeutic response and prognosis.

Case report: High-dose epoprostenol therapy in pediatric patients with pulmonary hypertension and developmental lung disease

Pulmonary hypertension (PH) with developmental lung disease is a life-threatening disease and accounts for 10%-12% of pediatric PH patients. Administration of specific pulmonary vasodilators to pediatric PH patients has brought about improvement of their long-term prognosis. Intravenous epoprostenol therapy is a gold standard therapy for severe idiopathic pulmonary arterial hypertension (IPAH), but there are few reports demonstrating the efficacy of epoprostenol for pediatric PH patients with developmental lung disease, especially when treating with high doses of epoprostenol. Two cases of pediatric PH patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) and congenital diaphragmatic hernia (CDH) with bronchopulmonary dysplasia (BPD), respectively, treated with epoprostenol above 100 ng/kg/min are presented. In these two cases, severe PH was improved significantly by an aggressive increase of the epoprostenol infusion rate with administration of oral pulmonary vasodilators and appropriate respiratory management, without any significant adverse effects. High-dose epoprostenol therapy may be one of the therapeutic options in pediatric PH patients with developmental lung disease.

Safety of chronic high-dose calcium channel blockers exposure in children with pulmonary arterial hypertension

Background

Chronic calcium channel blockers (CCBs) are indicated in children with idiopathic/heritable pulmonary arterial hypertension (IPAH/HPAH) and positive response to acute vasodilator challenge. However, minimal safety data are available on the long-term high-dose exposure to CCBs in this population.

Methods

Patients aged 3 months to 18 years who were diagnosed with IPAH/HPAH and treated with CCB in the past 15 years were retrospectively reviewed. The maximum tolerated dose and the long-term safety of high-dose CCBs on the cardiovascular and noncardiovascular systems were assessed.

Results

Thirty-two eligible children were enrolled in the study, with a median age of 9 (6–11) years old. Thirty-one patients were treated with diltiazem after diagnosis. The median maximum tolerated dose was 12.9 (9.8–16.8) mg/kg/day. Children younger than 7 years used higher doses than children in the older age group, 16.4 (10.5–28.5) mg/kg/day vs. 12.7 (6.6–14.4) mg/kg/day, P < 0.05. Patients were followed up for a median period of 6.2 (2.6–10.8) years. One patient died from a traffic accident, and others showed a stable or improved WHO functional class status. Thirteen (40.6%) and 10 (31.3%) patients developed arrhythmias and hypotension. Nine (28.1%) patients had sinus bradycardia, five (21.9%) had first-degree or second-degree type II atrial-ventricular blocks, and two (6.3%) had second-degree type II atrial-ventricular blocks. Most of these arrhythmias were transient and relieved after CCB dose adjustment. The most reported noncardiovascular adverse effect was gingival hyperplasia (13, 40.6%), accompanied by different degrees of dental dysplasia. No liver or kidney dysfunction was reported.

Conclusion

Diltiazem was used in a very high dose for eligible children with IPAH/HPAH. The toxicity of long-term CCB use on the cardiovascular system is mild and controllable. Clinicians should also monitor the noncardiovascular adverse effects associated with drug therapy.

Management of Pulmonary Hypertension in the Pediatric Patient

Pediatric pulmonary hypertension (PH) is a rare disease with historically very high morbidity and mortality. In the past 20 years, there has been a growing recognition that pediatric PH, although having similarities to adult PH, is a unique entity with its own particular pathogeneses, presentation, and management. With better understanding and earlier diagnosis of pediatric PH, and as more medications have become available, survival of children with PH has also significantly improved. This article reviews the various forms of PH in childhood, with a focus on both established and investigational therapies that are available for children with PH.

Cardiac catheterization in pediatric pulmonary hypertension: a systematic and practical approach

Significant progress in the understanding of the etiology, epidemiology, pathobiology and prognosis of pulmonary hypertension (PH) has been made over the last years. Especially in the pediatric patient population the etiology of PH is very heterogeneous. Nevertheless, the most recent change of the definition of PH to a mean pulmonary artery pressure (mPAP) >20 mmHg has been accepted by pediatricians for uniformity and concordance with adult physicians. Based on the diverse underlying medical conditions leading to PH, a comprehensive and systematic approach for diagnosis and treatment is mandatory. Cardiac catheterization remains the gold standard for invasive assessment and acute vasoreactivity testing (AVT) additionally providing detailed information about nature of PH. In most patients repeat cardiac catheterization may be helpful for evaluation of response to targeted PH treatment, risk stratification and indication for lung transplantation. However, the information and results taken from cardiac catheterization should be interpreted by experienced investigators only who are familiar with confounding factors that may influence the results. Here we provide an overview of current recommendations for invasive hemodynamic evaluation in pediatric PH. We point out different patient scenarios and provide a structured approach for AVT and response interpretation.

Selexipag use for paediatric pulmonary hypertension: a single centre report focussed on congenital heart disease patients

Pulmonary hypertension is a rare and complex disease with poor prognosis. Paediatric cases are infrequent and usually associated with congenital heart disease. Management is problematical due to the limited therapy available and poor evidence of efficacy. Recently a new medication, selexipag (UptraviR), a prostacyclin receptor agonist, has been approved for the treatment of pulmonary artery hypertension in adults. We report our experience using selexipag in four paediatric patients with pulmonary hypertension associated with congenital heart disease.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

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.

Outcomes of idiopathic pulmonary arterial hypertension in Japanese children: a retrospective cohort study

Recently, targeted therapy has been developed for idiopathic pulmonary arterial hypertension (IPAH). Studies evaluating the prognosis of IPAH have been conducted in adults. However, there is no nationwide survey of pediatric patients with IPAH regarding the long-term prognosis in Japan. Therefore, we investigated the clinical outcomes of Japanese pediatric patients with IPAH and risk factors for a poor prognosis. This multi-center, retrospective cohort study included pediatric patients with IPAH under the age of 15 years, who were gleaned from the nationwide network of Japanese Society of Pediatric Cardiology and Cardiac Surgery (JSPCCS). The questionnaire was sent to members of JSPCCS in 2015. Patients who were diagnosed with IPAH from 1994 to 2014 were included. The primary endpoint was death or lung transplantation. Ninety-five patients were finally enrolled. Both the mean age at diagnosis and the mean follow-up duration were 7 years. Ninety-five percent of patients had received targeted therapy for IPAH during follow-up. The overall 1, 3, 5, and 10-year event free rate, estimated using Kaplan-Meier survival estimate, was 96, 91, 83, and 74%, respectively. The prognosis was significantly poorer in patients with increased right ventricular systolic pressure (RVp), mean pulmonary artery pressure (mPAP) (≥ 52 mmHg), cardiothoracic ratio (≥ 55%), and levels of B-type natriuretic peptide (BNP) during follow-up (≥ 300 pg/mL) than in those without these parameters. In conclusion, in Japanese children with IPAH, the event-free rate for death or lung transplantation was found to be good. Greater RVp, mPAP, BNP levels during follow-up, and cardiothoracic ratio may be predictive indicators for a poor prognosis.

Intravenous prostacyclin-analogue therapy in pulmonary arterial hypertension - A review of the past, present and future

Therapy with intravenous prostacyclin analogues in patients with pulmonary arterial hypertension (PAH) has been established for decades and is an integral component of the current guidelines for the treatment of pulmonary hypertension. Initially, these drugs were infused by external pump systems via tunnelled right atrial catheters with the need for cooling and frequent exchange of drug reservoirs. Associated complications included, among others, catheter-related infections. More recently, fully implantable pump systems have been developed with drug reservoirs that are filled transcutaneously, allowing intervals between refills of several weeks. This technique results in a low rate of infections. Epoprostenol, iloprost and treprostinil have all been used intravenously in PAH, but titration, dosing and dose escalation in long-term therapy are not standardized. Intravenous prostacyclin analogues are still under-used, despite available data suggesting that early and broad application of these therapies as part of risk-oriented, guideline-directed combination therapy for patients with PAH may lead to a survival benefit. This review provides a detailed overview of the drugs, infusion systems and dosing strategies used for intravenous therapy in patients with PAH.

Prostanoids in pediatric pulmonary hypertension: clinical response, time-to-effect, and dose-response

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/m² 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.

Update on noninvasive imaging of right ventricle dysfunction in pulmonary hypertension

Pulmonary hypertension (PH) is a progressive disease affecting patients across the life span. The pathophysiology primarily involves the pulmonary vasculature and right ventricle (RV), but eventually affects the left ventricular (LV) function as well. Safe, accurate imaging modalities are critical for diagnosis, serial monitoring, and tailored therapy. While cardiac catheterization remains the conventional modality for establishing diagnosis and serial monitoring, noninvasive imaging has gained considerable momentum in providing accurate assessment of the entire RV-pulmonary axis. In this state-of-the-art review, we will discuss the most recent developments in echocardiography, magnetic resonance imaging, and computed tomography in PH evaluation from pediatric to adult population.

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.

Use of selexipag in a teenage patient with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic, progressive, multifactorial disease. Currently, combination therapy is an attractive option for PAH management because three pathways (endothelin, nitric oxide, and prostacyclin) are involved in this disease. Selexipag is a novel oral prostacyclin pathway drug and is a highly selective IP prostacyclin receptor agonist with vasodilatory and antiproliferative effects. We report the case of a teenage patient with idiopathic PAH who presented in World Health Organization functional Class IV and showed no clinical improvement with dual therapy. We added oral selexipag to the treatment regimen and observed substantial improvement in her quality of life at the short-time follow-up. Despite the lack of childhood data regarding the use of selexipag in pediatric patients with PAH, the use of this drug in the current teenage patient improved her quality of life and exercise capacity.

Drug Treatment of Pulmonary Hypertension in Children

Pulmonary arterial hypertension (PAH) is a rare disease in infants and children that is associated with significant morbidity and mortality. The disease is characterized by progressive pulmonary vascular functional and structural changes resulting in increased pulmonary vascular resistance and eventual right heart failure and death. In many pediatric patients, PAH is idiopathic or associated with congenital heart disease and rarely is associated with other conditions such as connective tissue or thromboembolic disease. PAH associated with developmental lung diseases such as bronchopulmonary dysplasia or congenital diaphragmatic hernia is increasingly more recognized in infants and children. Although treatment of the underlying disease and reversal of advanced structural changes have not yet been achieved with current therapy, quality of life and survival have improved significantly. Targeted pulmonary vasodilator therapies, including endothelin receptor antagonists, prostacyclin analogs, and phosphodiesterase type 5 inhibitors have resulted in hemodynamic and functional improvement in children. The management of pediatric PAH remains challenging as treatment decisions depend largely on results from evidence-based adult studies and the clinical experience of pediatric experts. This article reviews the current drug therapies and their use in the management of PAH in children.

Prostanoids and their analogues for the treatment of pulmonary hypertension in neonates

BACKGROUND

Persistent pulmonary hypertension of the newborn (PPHN) is a disease entity that describes a physiology in which there is persistence of increased pulmonary arterial pressure. PPHN is characterised by failure to adapt to a functional postnatal circulation with a fall in pulmonary vascular resistance. PPHN is responsible for impairment in oxygenation and significant neonatal mortality and morbidity. Prostanoids and their analogues may be useful therapeutic interventions due to their pulmonary vasodilatory and immunomodulatory effects.

OBJECTIVES

Primary objective• To determine the efficacy and safety of prostanoids and their analogues (iloprost, treprostinil, and beraprost) in decreasing mortality and the need for extracorporeal membrane oxygenation (ECMO) among neonates with PHSecondary objective• To determine the efficacy and safety of prostanoids and their analogues (iloprost, treprostinil, and beraprost) in decreasing neonatal morbidity (necrotizing enterocolitis (NEC), chronic lung disease (CLD), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), length of hospital stay, and duration of mechanical ventilation) and improving neurodevelopmental outcomes among neonates with PHComparisons• Prostanoids and their analogues at any dosage or duration used to treat PPHN versus 'standard treatment without these agents', placebo, or inhaled nitric oxide (iNO) therapy• Prostanoids and their analogues at any dosage or duration used to treat refractory PPHN as an 'add-on' therapy to iNO versus iNO alone SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 9), MEDLINE via PubMed (1966 to 16 September 2018), Embase (1980 to 16 September 2018), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 16 September 2018). We also searched clinical trials databases, conference proceedings of the Pediatric Academic Societies (1990 to 16 September 2018), and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials. We contacted authors who have published in this field as discerned from the reference lists of identified clinical trials and review authors' personal files.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials evaluating prostanoids or their analogues (at any dose, route of administration, or duration) used in neonates at any gestational age less than 28 days' postnatal age for confirmed or suspected PPHN.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal to conduct a systematic review and to assess the methodological quality of included studies (neonatal.cochrane.org/en/index.html). Three review authors independently assessed the titles and abstracts of studies identified by the search strategy and obtained full-text versions for assessment if necessary. We designed forms for trial inclusion or exclusion and for data extraction. We planned to use the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We did not identify any eligible neonatal trials evaluating prostanoids or their analogues as sole agents in the treatment of PPHN.

AUTHORS' CONCLUSIONS

Implications for practiceCurrently, no evidence shows the use of prostanoids or their analogues as pulmonary vasodilators and sole therapeutic agents for the treatment of PPHN in neonates (age 28 days or less).Implications for researchThe safety and efficacy of different preparations and doses and routes of administration of prostacyclins and their analogues in neonates must be established. Well-designed, adequately powered, randomized, multi-center trials are needed to address the efficacy and safety of prostanoids and their analogues in the treatment of PPHN. These trials should evaluate long-term neurodevelopmental and pulmonary outcomes, in addition to short-term outcomes.

Treatment of pediatric pulmonary arterial hypertension: A focus on the NO-sGC-cGMP pathway

OBJECTIVE

While pulmonary arterial hypertension (PAH) is rare in infants and children, it results in substantial morbidity and mortality. In recent years, prognosis has improved, coinciding with the introduction of new PAH-targeted therapies, although much of their use in children is off-label. Evidence to guide the treatment of children with PAH is less extensive than for adults. The goal of this review is to discuss the treatment recommendations for children with PAH, as well as the evidence supporting the use of prostanoids, endothelin receptor antagonists (ERAs), and phosphodiesterase type 5 inhibitors (PDE5i) in this setting.

DATA SOURCES

Nonsystematic PubMed literature search and authors' expertise.

STUDY SELECTION

Articles were selected concentrating on the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway in PAH. The methodology of an ongoing study evaluating the sGC stimulator riociguat in children with PAH is also described.

RESULTS

Despite recent medical advances, improved therapeutic strategies for pediatric PAH are needed. The efficacy and tolerability of riociguat in adults with PAH have been well trialed.

CONCLUSION

The pooling of data across trials, supplemented by registry data, will help to confirm the safety and tolerability of prostanoids, ERAs, and PDE5i in children. Ongoing studies will clarify the place of sGC stimulators in the treatment strategy for pediatric PAH.

Current understanding and perioperative management of pediatric pulmonary hypertension

Pediatric pulmonary hypertension is a complex disease with multiple, diverse etiologies affecting the premature neonate to the young adult. Pediatric pulmonary arterial hypertension, whether idiopathic or associated with congenital heart disease, is the most commonly discussed form of pediatric pulmonary hypertension, as it is progressive and lethal. However, neonatal forms of pulmonary hypertension are vastly more frequent, and while most cases are transient, the risk of morbidity and mortality in this group deserves recognition. Pulmonary hypertension due to left heart disease is another subset increasingly recognized as an important cause of pediatric pulmonary hypertension. One aspect of pediatric pulmonary hypertension is very clear: anesthetizing the child with pulmonary hypertension is associated with a significantly heightened risk of morbidity and mortality. It is therefore imperative that anesthesiologists who care for children with pulmonary hypertension have a firm understanding of the pathophysiology of the various forms of pediatric pulmonary hypertension, the impact of anesthesia and sedation in the setting of pulmonary hypertension, and anesthesiologists' role as perioperative experts from preoperative planning to postoperative disposition. This review summarizes the current understanding of pediatric pulmonary hypertension physiology, preoperative risk stratification, anesthetic risk, and intraoperative considerations relevant to the underlying pathophysiology of various forms of pediatric pulmonary hypertension.

Diagnosis and treatment of pediatric pulmonary arterial hypertension

INTRODUCTION

Pediatric pulmonary arterial hypertension (PAH) remains a rare and severe disease with a poor prognosis. PAH may be idiopathic, heritable or associated with systemic conditions in particular associated with congenital heart disease. Areas covered: A thorough and extensive diagnostic approach is required for a correct diagnosis. The outcome has improved over the last decade with a better diagnostic approach and with the initiation of new targeted therapies. However, there is still significant progress to achieve as there is still no cure for this devastating disease. Expert opinion: Adapted clinical studies to define the best therapeutic approach are needed. Even if the treatment approach is still mainly derived from adult data and expert consensus, several studies and registries are currently underway and should deliver important information in the next future. This review aims to give an overview of the current diagnosis and treatment strategies of PAH.

Acute vasodilator testing: An opportunity to advance the precision care of pulmonary hypertension

The pulmonary arterial pressure of a child with severe pulmonary arterial hypertension immediately normalized while breathing nitric oxide during heart catheterization at 8 years of age. Her acute pulmonary vascular response to nitric oxide has persisted throughout her life. Her acute response to other medications has been similar to her long-term response to medications in the same class. Acute vasodilator testing with inhaled nitric oxide and other medications may be an opportunity to refine study design and advance precision care for patients with pulmonary hypertension.

Paediatric pulmonary arterial hypertension: updates on definition, classification, diagnostics and management

Paediatric pulmonary arterial hypertension (PAH) shares common features of adult disease, but is associated with several additional disorders and challenges that require unique approaches. This article discusses recent advances, ongoing challenges and distinct approaches for the care of children with PAH, as presented by the Paediatric Task Force of the 6th World Symposium on Pulmonary Hypertension. We provide updates of the current definition, epidemiology, classification, diagnostics and treatment of paediatric PAH, and identify critical knowledge gaps. Several features of paediatric PAH including the prominence of neonatal PAH, especially in pre-term infants with developmental lung diseases, and novel genetic causes of paediatric PAH are highlighted. The use of cardiac catheterisation as a diagnostic modality and haemodynamic definitions of PAH, including acute vasoreactivity, are addressed. Updates are provided on issues related to utility of the previous classification system to reflect paediatric-specific aetiologies and approaches to medical and interventional management of PAH, including the Potts shunt. Although a lack of clinical trial data for the use of PAH-targeted therapy persists, emerging data are improving the identification of appropriate targets for goal-oriented therapy in children. Such data will likely improve future clinical trial design to enhance outcomes in paediatric PAH.

Bosentan for Treatment of Pediatric Idiopathic Pulmonary Arterial Hypertension: State-of-the-Art

Idiopathic pulmonary arterial hypertension (IPAH) is a complex disease associated with progressive deterioration. Targeted therapy for IPAH has improved in the last several decades. However, there remain many challenges to current treatment of children with IPAH, including poor prognosis and a median survival of 0.8 years. Endothelin-1 (ET-1) appears to be a key mediator in the pathogenesis of IPAH, with elevated concentrations in the plasma. Bosentan, an endothelin receptor antagonist, has been confirmed in Food and Drug Administration (FDA) to effectively treat IPAH when administered in recent studies. This review focuses on related studies and advance of bosentan in the treatment of IPAH in children.

Assessment of quality of life in pediatric patients with pulmonary hypertension

The aim of this study is to evaluate quality of life in four domains (physical, emotional, social, and school) in pediatric patients with pulmonary hypertension (PH) using a validated survey (PedsQL). This is a prospective cohort study of pediatric patients aged 2–18 years with PH. Parents of all children and patients aged 8–18 years with appropriate developmental capacity completed the PedsQL survey in the clinic. Results were compared with published norms for pediatric patients, those with congenital heart disease (CHD) and cancer. Thirty-three children were enrolled yielding 32 parent and 18 patient self-reports: seven patients were aged 2–4 years; three were aged 5–7 years; 11 were aged 8–12 years, and 12 were aged 13–18 years. Twenty-one patients were classified as World Health Organization (WHO) Group I pulmonary arterial hypertension (PAH), 11 WHO Group III PH due to lung disease, and one WHO Group V with segmental PH. Thirteen patients were NYHA functional class (FC) 1, 12 were FC 2, eight were FC 3, and none were FC 4. The PH cohort had significantly lower scores than healthy children in all domains on both parent and self-report. The PH cohort also had significantly lower scores than patients with CHD (parent report: total, physical, social, school; patient self-report: total, physical, school) and cancer (parent report: school; patient self-report: physical, school). Close to 50% of participants reported at risk scores in each domain. The quality of life in pediatric PH patients assessed by PedsQL revealed functional impairment in multiple domains. Administration of the PedsQL during outpatient encounters may provide an easy, reproducible method to assess quality of life and direct referral for interventional services.

An update on the diagnosis and management of bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension

The past decade of neonatal care has been highlighted by increased survival rates in smaller and more premature infants. Despite reduction in mortality associated with extreme prematurity, long term pulmonary morbidities remain a concern, with growing recognition of the clinical burden attributable to infants with bronchopulmonary dysplasia (BPD)-associated pulmonary hypertension (PH). Recent publications shed light on the critical contributions of maternal placental pathology and compromised intrauterine growth to fetal pulmonary vascular development. A body of literature has further clarified postnatal risk factors for PH, most notably the severity of BPD but surprisingly the additional presence of non-pulmonary morbidities including necrotizing enterocolitis (NEC). Limitations of current diagnostics persist with growing consideration of novel echocardiographic approaches as well as complementary non-invasive biomarkers to better identify infants at risk. In 2015, a joint report published by the American Heart Association and American Thoracic Society provided the first guidelines for the care of children with PH with limited content to address BPD-associated PH. These guidelines were expanded upon in an expert consensus report produced by the Pediatric Pulmonary Hypertension Network (PPHNet). These recommendations encouraged the use of standardized screening protocols and emphasized the importance of evaluation and treatment of comorbidities when PH is identified. Cardiac catheterization was recommended prior to initiation of therapy for more accurate quantification of pulmonary pressures, clarification of anatomy and guidance in the use of pharmacotherapy. Despite these guidelines, significant practice variation persists and gaps remain with respect to optimal evaluation and management of BPD-associated PH.

Intravenous epoprostenol improves oxygenation index in patients with persistent pulmonary hypertension of the newborn refractory to nitric oxide

OBJECTIVES

Evaluate the short-term effects of IV epoprostenol in neonates with persistent pulmonary hypertension (PPHN) of the newborn.

STUDY DESIGN

We reviewed 36 patients with inhaled nitric oxide (iNO) refractory PPHN placed on IV epoprostenol from 2010 to 2015. Patients were categorized as responders or non-responders (who either died or required extracorporeal membranous oxygenation).

RESULTS

There were 15 responders and 21 non-responders. Pulmonary hypoplasia was the etiology of PPHN for 57% of non-responders vs. 13% of responders. Median oxygenation index (OI) was similar at baseline (41.8 non-responders vs. 36.5 responders, p = 0.41) with responders having a significantly lower OI by 4 h of treatment (42.3 vs. 23.1, p = 0.002). Epoprostenol responders had a median OI decrease of 11.6 within 4 h (p = 0.017) with a significant response persisting through 24 h.

CONCLUSION

In infants with iNO-refractory PPHN, initiation of IV epoprostenol was associated with a significant and rapid OI reduction among responders.

Intravenous treprostinil via an implantable pump in pediatric pulmonary arterial hypertension

Intravenous prostacyclin-based therapy improves survival in children with pulmonary arterial hypertension (PAH), but is typically administered via an external infusion pump, which places a considerable burden on the patient. Implanted pumps may overcome some of the limitations of external pumps. We describe the first long-term use of an implanted pump for intravenous treprostinil delivery in a pediatric patient with PAH. Our patient was experiencing marked dyspnea on exertion despite triple combination therapy with bosentan, sildenafil, and inhaled iloprost. Parenteral prostacyclin-based therapy was discussed and the patient rejected options involving external pumps; she finally chose intravenous treprostinil delivery via an implanted pump (LENUS Pro®; fixed flow rate; 20 ml reservoir). The patient underwent pump implantation in July 2012 (aged 14 years) under general anesthesia with no peri- or postoperative complications. She showed marked improvements in fatigue and dyspnea over the subsequent weeks, and her inhaled iloprost regimen was slowly decreased and stopped after six months. During follow-up, the pump showed an unexpected, progressive increase in flow rate that allowed a treprostinil dose of 170 ng/kg/min to be achieved, but at the cost of shortened intervals between refills. The pump was therefore replaced in August 2017 with a newer model with an adjustable flow rate (Siromedes®). A catheter dislocation was corrected under local anesthesia one week after the replacement surgery. The patient is currently receiving treprostinil 170 ng/kg/min with percutaneous refills every 12–13 days. Thus, implantable pumps might be a valuable alternative to external pumps for treprostinil infusion in pediatric PAH.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Diagnosis, Evaluation and Treatment of Pulmonary Arterial Hypertension in Children

Pulmonary Hypertension (PH), the syndrome of elevated pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children. PH is associated with a wide variety of potential underlying causes, including cardiac, pulmonary, hematologic and rheumatologic abnormalities. Regardless of the cause, for many patients the natural history of PH involves progressive elevation in pulmonary arterial resistance and pressure, right ventricular dysfunction, and eventually heart failure. In recent years, a number of pulmonary arterial hypertension (PAH)-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome. A growing body of evidence in both the adult and pediatric literature demonstrates enhanced quality of life, functional status, and survival among treated patients. This review provides a description of select etiologies of PH seen in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH/PAH. The available evidence for specific classes of PAH-targeted therapies in pediatrics is additionally discussed.

Safety, efficacy and Management of subcutaneous treprostinil infusions in the treatment of severe pediatric pulmonary hypertension

BACKGROUND

Continuous intravenous epoprostenol was the first treatment approved for pulmonary arterial hypertension (PAH) but administration through a central venous line carries risks of thrombosis and sepsis, particularly in children. We sought to evaluate the safety, efficacy and management of subcutaneous (SC) treprostinil in children with PAH.

METHODS

Fifty-six children (median age 65, range 1-200 months) were treated with SC treprostinil. Clinical status, echocardiography, NT-proBNP, and site pain and infection were evaluated. Right heart catheterization was performed in 54 patients before starting SC treprostinil infusion and was repeated at 6 months in 31 patients.

RESULTS

Treatment was well tolerated in 79% of patients. Site pain resistant to simple analgesics occurred in 12 patients (21%), but could be managed in 9/12 children. At 6 months, 3 patients had died, 4 had received a Potts shunt and 1 underwent lung transplantation. Among the 48 treated patients, 40 (83%) showed significant improvement in WHO functional class, 6 minute walk distance, NT-proBNP and pulmonary vascular resistance (p < 0.01 for all parameters). At last follow-up (median 37 months), ten patients had died, 2 underwent a lung transplantation and 8 underwent a Potts shunt. In 30 of the 36 remaining treated patients, improvement of clinical status was sustained. No children developed sepsis and 12 had minor site infections.

CONCLUSION

Subcutaneous treprostinil infusion is an effective therapy without serious side effects in children with PAH. Site pain can be managed with simple analgesics in most children.

Acute Pulmonary Vasodilator Testing and Long-Term Clinical Course in Segmental Pulmonary Vascular Disease

Results of acute pulmonary vasodilator testing (AVT) and the outcome of medical therapy have not been described in patients with segmental pulmonary vascular disease (SPVD). We sought to compare the pulmonary vasodilatory effects of oxygen, oxygen with nitric oxide, and diltiazem, and to describe the clinical course of patients with SPVD and pulmonary hypertension. A retrospective review of 16 patients with pulmonary hypertension and SPVD involving 2-3 major lung segments who underwent AVT between January 2000 and December 2015 was performed. Baseline hemodynamic measurements were obtained with patients breathing ≤ 30% oxygen. AVT was performed using 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21-35% oxygen, and 21-35% oxygen with intravenous diltiazem. The events associated with their long-term care were described. Nine of 16 patients were acutely responsive during AVT using the Sitbon criteria. The change in mean pulmonary artery pressure with oxygen or oxygen with nitric oxide (19 ± 12 mmHg) was significantly greater than the change with diltiazem (7 ± 5 mmHg). Pulmonary vasodilator therapy was initiated or escalated after AVT in 12 patients. Five patients subsequently experienced a decrease in mean pulmonary artery pressure or normalization in B-type natriuretic peptide. Three patients experienced adverse events associated with therapy. The actuarial survival was 94% over a period of 1-20 years. This study suggests that AVT can be used to identify patients with SPVD who are reactive to oxygen, oxygen with nitric oxide, and diltiazem. Clinical improvement was temporally associated with pulmonary vasodilator therapy in some patients with few adverse effects.

Use of subcutaneous treprostinil in pediatric pulmonary arterial hypertension-Bridge-to-transplant or long-term treatment?

PAH is a progressive life-threatening disease in children. While parenteral prostacyclin therapy improves survival in patients with severe PAH, central line-related complications are common. Our aim was to assess the efficacy, safety, and tolerability of subcutaneous treprostinil treatment in pediatric PAH patients. Eight patients were treated with subcutaneous treprostinil at the Pediatric Heart Center Budapest. Indications for subcutaneous treprostinil therapy were clinical worsening and/or echocardiographic progression or switch from intravenous to subcutaneous therapy. Following treprostinil initiation, clinical status improved or did not change in four of eight patients. Two patients were lost early during treprostinil therapy, parenteral treprostinil as a rescue therapy being insufficient in these cases. The final dose in long-term treated patients was between 60 and 100 ng/kg/min. Aside from thrombocytopenia, other severe side effects were not observed. Potts shunt was performed as palliative treatment in two cases. Three patients had successful lung transplantation, and one died while on the waiting list. Long-term subcutaneous treprostinil could be a safe and well-tolerated therapy in children with severe PAH even at higher doses. It may serve as an alternative to intravenous prostacyclin treatment allowing to avoid the potential complications of permanent central line placement.

Characterization of CMR-derived haemodynamic data in children with pulmonary arterial hypertension

Aims

Paediatric pulmonary arterial hypertension (PAH) is manifested as increased arterial pressure and vascular resistive changes followed by progressive arterial stiffening. The aim of this study was to characterize regional flow haemodynamic patterns and markers of vascular stiffness in the proximal pulmonary arteries of paediatric PAH patients, and to explore the association with right ventricular (RV) function.

Methods and results

Forty paediatric PAH patients and 26 age- and size-matched controls underwent cardiac magnetic resonance studies in order to compute time-resolved wall shear stress metrics, oscillatory shear index (OSI), and vascular strain as measured by relative area change (RAC), and RV volumetric and functional parameters. Phase-contrast imaging planes were positioned perpendicular to the mid-main and right pulmonary arteries (MPA and RPA, respectively). Compared with controls, the PAH group had decreased systolic wall shear stress (dyne cm-2) and RAC (%) in both MPA (WSSsys: 6.5 vs. 4.3, P < 0.0001; RAC: 36 vs. 25, P < 0.0001) and RPA (WSSsys: 11.2 vs. 7.3, P < 0.0001; strain: 37 vs. 30, P < 0.05). The OSI was significantly higher in the MPA of PAH subjects (0.46 vs. 0.17, P < 0.05). WSS measured in the MPA correlated positively with RAC (r = 0.63, P < 0.0001) and RV ejection fraction (%) (r = 0.63, P < 0.0001).

Conclusion

Wall shear stress, the principal haemodynamic force driving endothelial functional changes, is severely decreased in paediatric PAH patients and correlates with increased stiffness in the proximal pulmonary vasculature and reduced RV function.

Pulmonary hypertension's variegated landscape: a snapshot

The many types of pulmonary hypertension (PH) are so protean in their biological origin, histological expression, and natural history that it is difficult to create a summary picture of the disease, or to easily compare and contrast characteristics of one type of PH with another. For newcomers to the field, however, such a picture would facilitate a broad understanding of PH. In this paper, we suggest that four characteristics are fundamental to describing the nature of various types of PH, and that taken together they define a number of patterns of PH expression. These characteristics are histopathology, developmental origin, associated clinical conditions, and potential for resolution. The “snapshot” is a way to concisely display the ways that these signal characteristics intersect in select specific types of PH, and is an effort to summarize these patterns in a way that facilitates a “big picture” comprehension of this disease.

Genetic analyses in a cohort of children with pulmonary hypertension

The prevalence of germline mutations in paediatric pulmonary hypertension (PH) is poorly documented. The objective of this study was to determine the mutation frequency in PH genes in a paediatric cohort and describe the clinical characteristics of mutation carriers.The study involved 66 index cases with PH: 35 children with idiopathic pulmonary arterial hypertension (IPAH); five children with familial PAH (FPAH); three children with pulmonary veno-occlusive disease (PVOD); and 23 children with PAH associated with congenital heart disease (APAH-CHD).No mutations were found in the 23 children with APAH-CHD. In the 40 children with IPAH or FPAH, 12 mutations were found: five on BMPR2; four on ACVRL1; and three on TBX4. In the three PVOD cases, two carried the EIF2AK4 mutation. Mutation carriers had a more severe disease at diagnosis and more aggressive first-line therapy was required. The three patients with PVOD had a very severe disease at diagnosis and required a lung transplantation.The genetic architecture of paediatric PAH is enriched in ACVRL1 and TBX4 mutations compared to adult PAH, but further studies are required to confirm these results. Childhood-onset PAH in children carrying a mutation in one of the genes tested has a more severe presentation at diagnosis but a similar outcome to that observed in non-carriers.

Treatment of children with pulmonary hypertension. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Treatment of children and adults with pulmonary hypertension (PH) with or without cardiac dysfunction has improved in the last two decades. The so-called pulmonary arterial hypertension (PAH)-specific medications currently approved for therapy of adults with PAH target three major pathways (endothelin, nitric oxide, prostacyclin). Moreover, some PH centres may use off-label drugs for compassionate use. Pulmonary hypertensive vascular disease (PHVD) in children is complex, and selection of appropriate therapies remains difficult. In addition, paediatric PAH/PHVD therapy is vastly based on experience and trial data from adult rather than paediatric studies; however, the first randomised paediatric PAH trials have been conducted recently. We present consensus recommendations for the treatment of children with PH. Class of recommendation and level of evidence were assigned based on paediatric data only or on adult studies that included >10% children. After a systematic literature search and analysis of the published data, we developed treatment strategies and algorithms that can guide goal-oriented PH therapy. We discuss early combination therapy (double, triple) in patients with PAH in functional class II-IV and in those with inadequate response to the initial pharmacotherapy. In those children with progressive, severe PAH and inadequate response, advances in drug development, and interventional and surgical approaches provide promising new strategies to avoid, reverse or ameliorate right heart failure and left ventricular compression. In particular, first follow-up data indicate that Potts shunt (left pulmonary artery to descending aorta anastomosis) may be an alternative destination therapy, or bridge to bilateral lung transplantation, in end-stage paediatric PAH.

Pulmonary Hypertension in Children

The prevalence of PH is increasing in the pediatric population, because of improved recognition and increased survival of patients, and remains a significant cause of morbidity and mortality. Recent studies have improved the understanding of pediatric PH, but management remains challenging because of a lack of evidence-based clinical trials. The growing contribution of developmental lung disease requires dedicated research to explore the use of existing therapies as well as the creation of novel therapies. Adequate study of pediatric PH will require multicenter collaboration due to the small numbers of patients, multifactorial disease causes, and practice variability.

The limits of oral therapy in pulmonary arterial hypertension management

Pulmonary arterial hypertension (PAH) is a devastating disease in which remodeling of the small pulmonary arteries leads to a progressive increase in pulmonary vascular resistance and right-sided heart failure. Over the past decade, new treatments for PAH, such as the use of ERAs, PDE-5 inhibitors and prostacyclin analogs, have brought about dramatic improvements in clinical outcomes. Epoprostenol infusion therapy has been shown to improve hemodynamics, functional status, and survival, and it remains the gold standard for treatment of patients with severe PAH. Many agents, approved for PAH are always delivered in pill form. Although oral therapy occupies an important position, it has some drawbacks and limitations in PAH management. For patients in World Health Organization functional class IV and with severe right heart failure, there are few data on the long-term survival of patients treated with oral medications. Further research, exploration, and clinical experience with oral therapy in severe PAH and combination therapy will redefine its position in PAH management.

Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society

Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.