Treating pulmonary hypertension in pediatrics

Selexipag for the Treatment of Pediatric Pulmonary Hypertension: A Systematic Review

PURPOSE

To systematically evaluate the safety, dosing regimen, and efficacy of selexipag for pediatric patients with pulmonary hypertension (PH).

METHODS

A literature search of the electronic databases of PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar was performed from inception through February 28, 2023. Two reviewers independently searched and evaluated the quality of the studies and pooled data when appropriate. Full-text articles of studies of children diagnosed with PH and treated with selexipag were eligible. Pediatric patients with PH were classified into 2 groups: the add-on therapy group, in which selexipag was used as a third therapy in addition to the baseline treatment, and the transition therapy group, in which patients were switched from parenteral prostacyclin analogs to selexipag.

FINDINGS

Fourteen studies involving 58 pediatric patients with PH were included. All studies were either case reports or case series. Overall, 30 and 28 patients were in the add-on and transition therapy groups, respectively. In both groups, selexipag was initially administered as 50-200 µg twice daily and titrated to a tolerated dosage of 200-1,600 µg twice daily. Prostacyclin analogs were simultaneously weaned for patients in the transition group. In the add-on therapy group, 16 patients (80.0%) were at low risk of the World Health Organization functional class (WHO FC I/II), 12 (76.9%) were at low risk of the 6-minute walk distance (6MWD; >350 m), and 21 (95.5%) were at low risk of the pulmonary vascular resistance index (PVRi; <20 WU/m2). Furthermore, N-terminal pro-brain natriuretic peptide and mean pulmonary arterial pressure were significantly improved. More than 70% of patients experienced common tolerable side effects, such as headache, nausea, and diarrhea. In the transition therapy group, 5 patients (55.6%) were at low risk according to WHO FC I/II, 6 (66.7%) were at low risk according to 6MWD, and 14 (87.5) were at low risk according to PVRi; however, selexipag had no significant effect on their hemodynamic parameters. Additionally, more than 80% of patients experienced no side effects.

IMPLICATIONS

Selexipag as add-on therapy or for transition from prostacyclin analogs may have a favorable safety profile and potential efficacy for pediatric patients with PH. Further high-quality evidence of the efficacy and safety of selexipag for the treatment of pediatric PH is warranted.

Tadalafil Nanoemulsion Mists for Treatment of Pediatric Pulmonary Hypertension via Nebulization

Oral tadalafil (TD) proved promising in treating pediatric pulmonary arterial hypertension (PAH). However, to ensure higher efficacy and reduce the systemic side effects, targeted delivery to the lungs through nebulization was proposed as an alternative approach. This poorly soluble drug was previously dissolved in nanoemulsions (NEs). However, the formulations could not resist aqueous dilution, which precluded its dilution with saline for nebulization. Thus, the current study aimed to modify the previous systems into dilutable TD-NEs and assess their suitability for a pulmonary application. In this regard, screening of various excipients was conducted to optimize the former systems; different formulations were selected and characterized in terms of physicochemical properties, nebulization performance, stability following sterilization, and biocompatibility. Results showed that the optimal system comprised of Capmul-MCM-EP:Labrafac-lipophile (1:1) (w/w) as oil, Labrasol:Poloxamer-407 (2:1) (w/w) as surfactant mixture (S_mix) and water. The optimum formulation P2_TD resisted aqueous dilution, exhibited reasonable drug loading (2.45 mg/mL) and globule size (25.04 nm), acceptable pH and viscosity for pulmonary administration, and could be aerosolized using a jet nebulizer. Moreover, P2_TD demonstrated stability following sterilization and a favorable safety profile confirmed by both in-vitro and in-vivo toxicity studies. These favorable findings make P2_TD promising for the treatment of pediatric PAH.

Opportunities and challenges of pharmacotherapy for pulmonary arterial hypertension in children

Pediatric pulmonary hypertension (PAH) is a rare disease that carries a poor prognosis if left untreated. Although there are published guidelines for the treatment of children with pulmonary hypertension, due to the limited number of robust pediatric clinical trials, recommendations are often based on limited data or clinical experience. Furthermore, many practical aspects of care, particularly for the pediatric patient, are learned through experience and best navigated with a multidisciplinary team. While newer PAH therapies have been approved for adults, there is still limited but expanding experience in pediatrics. This new information will help improve the targets of goal-oriented therapy. Lastly, this review highlights practical aspects in the use of the different therapies available for the treatment of pediatric pulmonary hypertension.

An update on the diagnosis and treatment of pediatric pulmonary hypertension

INTRODUCTION

Pulmonary hypertension (PH) is a heterogeneous disease that mainly affects the pulmonary arterioles, leading to significant morbidity and mortality. Pulmonary hypertension in children from birth to adolescence presents important differences from that of adults. The majority of pediatric pulmonary arterial hypertension (PAH) cases are idiopathic or associated with congenital heart disease. However, the management of pediatric PAH mainly depends on the results of evidence-based adult studies and the clinical experiences of pediatric experts.

AREAS COVERED

This article briefly reviews the recent updates on the definition, classification, and diagnostic evaluation of pediatric PAH and their impact on treatment strategies. The main purpose of this review is to discuss the current pediatric therapies, as well as the prospective therapies, in terms of therapeutic targets, actions, side effects, and dosages.

EXPERT OPINION

Although there is no cure for PAH, recent advances in the form of new treatment options have improved the quality of life and survival rates of PAH patients. PAH-targeted drugs and treatment strategies for adult PAH have not been sufficiently studied in children. However, the growing scientific activity in that field will surely change the treatment option recommendations in pediatric PH from experience-based to evidence-based in the near future.

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.

EXPRESS: Sildenafil for bronchopulmonary dysplasia and pulmonary hypertension: a meta-analysis

Bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants and often complicated by pulmonary hypertension (PH), leading to substantial morbidity and mortality. Sildenafil is often used to treat PH and improve symptoms in this condition, even though evidence of safety and effectiveness is scarce. The aim of this study was to perform a systematic review and meta-analysis about the effectiveness and safety of chronic use of sildenafil in preterm infants with BPD-associated PH. Data sources were PubMed, EMBASE, and Medline. Studies reporting the effectiveness of sildenafil therapy in BPD-associated PH in newborns and infants were included. All-cause mortality, improvement in PH, improvement in respiratory scores, and adverse events were extracted. Five studies were included, yielding a total of 101 patients with 94.2 patient-years of total follow-up. The pooled mortality rate was 29.7%/year (95% confidence interval [CI] = 6.8–52.7). Estimated pulmonary arterial pressure improved > 20% in 69.3% (95% CI = 56.8–81.8) of patients within 1–6 months. Respiratory scores improved in 15.0% (95% CI = 0.0–30.4) of patients within 2–7 days. There were no serious adverse events during sildenafil therapy. This systematic review shows that in the treatment of BPD-associated PH in preterm infants, sildenafil may be associated with improvement in PAP and respiratory scores. However, there is no clear evidence of its effect on mortality rates. Considering BPD as a complex disease with variable expression patterns, these results support the need for a prospective registry and standardized approach.

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.

Vasoreactive Pulmonary Arterial Hypertension Manifesting With Misleading Epileptic Seizure: Diagnostic and Treatment Pitfalls

A 5-year-old girl presented with acute nocturnal episodes of loss of consciousness following abdominal pain and crying. Epilepsy was primarily diagnosed but the course of the disease was suggestive of pulmonary hypertension. An adapted invasive assessment of pulmonary pressure and pharmacological challenge allowed for diagnosing vasoreactive pulmonary arterial hypertension. Initial treatment with sildenafil was not effective. Thus, calcium channel blockers were introduced when positive vasoreactivity was confirmed and permitted to stop the occurrence of the syncope and dramatically improved clinical status. At 2 years follow-up she is well without any complaint and in functional class I. Echocardiography shows a slightly enlarged but not hypertrophied right ventricle with a nearly normalized estimated right ventricular pressure. The last catheterization shows subnormal values of pulmonary arterial pressure (mean pulmonary artery pressure: 24 mmHg) and pulmonary vascular resistance (5, 4 Wood units^*m²), normalizing with inhaled Nitric Oxide (mean pulmonary artery pressure of 14 mmHg and pulmonary vascular resistance of 1.5 Wood units^*m²). Vasoreactive pulmonary arterial hypertension is a rare entity in children but it should not be misdiagnosed with seizures due to the presence of syncopal episodes. According to current knowledge, this form seems to have a better prognosis than non-reactive pulmonary arterial hypertension and the treatment of choice remains as calcium channel blockers. The management of this case was characterized by successive mishaps and potentially harmful mistakes and underscores the potential risk with pediatric PH evaluation in non-expert centers.

Pharmacokinetics of drugs for pediatric pulmonary hypertension

BACKGROUND

Over the past few years, several drugs, each with a different mechanism, have been developed for the treatment of pulmonary hypertension (PH) and are now prescribed in the clinical setting. While the optimal doses of these drugs in adults have been determined, the optimal dose in children, however, is unclear. The aim of this study was therefore, to measure blood drug levels and analyze the pharmacokinetics of two such drugs in children.

METHODS

From April 2010 to May 2015, we prospectively enrolled 23 children with PH for treatment with bosentan and/or tadalafil. Twenty children were treated with bosentan and 19 received tadalafil. Sixteen children were given both drugs. Blood samples were collected after 2 weeks of treatment, and blood drug levels measured using high-performance liquid chromatography.

RESULTS

For both drugs, the peak plasma concentration was lower and the half-life was shorter than the known values in adults. The blood trough level of bosentan significantly correlated with its dose, but no such correlation was seen for tadalafil. For both drugs, no correlation was observed between age and blood drug levels.

CONCLUSIONS

Oral dosing with bosentan and tadalafil in children may not achieve therapeutic blood concentration. Thus, the optimal dosing must be established individually while monitoring blood drug level.

Executive Summary of the American Heart Association and American Thoracic Society Joint Guidelines for Pediatric Pulmonary Hypertension

Although pulmonary hypertension (PH) contributes significantly to poor outcomes in diverse pediatric diseases, approaches toward the care of children with PH 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 committee of experienced clinicians was formed to systematically identify, synthesize, and appraise relevant evidence and then to formulate evidence-based recommendations regarding the diagnosis and management of pediatric PH. This brief report is an executive summary of the officially approved guidelines developed by the committee, highlighting a few key recommendations regarding the care of children with PH. Guidelines and the rationale for grading the strength of each recommendation are included in the online supplement.

Pulmonary hypertension in the elderly: a different disease?

Pulmonary hypertension (PH) is a haemodynamic syndrome defined by a mean pulmonary arterial pressure (mPAP) >25 mmHg determined by right heart catheterisation (RHC) [1, 2]. A lot of ­diseases fulfil this definition, but they differ widely between each other in respect to their pathophysiology, their haemodynamic characteristics, their clinical presentation, their natural prognosis and their potential therapeutic strategies. The current guidelines on PH diagnosis and management make the distinction between five groups of more than 200 causes of PH [2], but these diseases are very different from one another. In the current classification, the first group (group 1) represents a progressive vasculopathy leading to pre-capillary PH called pulmonary arterial hypertension (PAH), characterised by a characteristic small-calibre pulmonary artery remodelling, as a result of proliferation of endothelial and smooth muscle cells as well as medial hypertrophy. So, if we compare PAH (for example idiopathic PAH) from PH due to valvular disease like mitral insufficiency (group 2.3) it is easy to understand that apart from the fact that mean pulmonary arterial pressure (mPAP) exceeds 25 mmHg in both cases, these two entities have very different pathophysiological pathways. In the first case, there is a true pulmonary vasculopathy. In the second, PH is mainly related to the consequences of an increased hydrostatic pressure in the left atrium ­transmitted to the venous compartment of the pulmonary circulation and then back through the capillary bed. If the pathophysiology of these entities is different, the targets of their treatments are too. The main goal of PAH treatment consists in reducing pulmonary vascular resistance (PVR) with specific medication and, when appropriate, with specific treatment of the underlying disease as it is the case for associated-PAH (group 1.4). Alternatively, the management of PH related to a mitral regurgitation would be to improve the ventricular preload, diminish the ventricular afterload and, if necessary, to correct the anatomical anomaly.

The distinction between PH in the elderly and normal ageing might make diagnosis difficulthttp://ow.ly/YYF1Q