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

Genotypes and Phenotypes: Making Progress Toward a Precision Medicine Approach in Pediatric Pulmonary Hypertension

Pediatric pulmonary hypertension (PH) is a heterogeneous disease that includes etiologies related to growth and development that are unique to children. Recent pediatric registry studies have characterized diverse phenotypes even within recognized PH subtypes, including PH associated with congenital heart disease and developmental lung disease. Advances in genetics are resulting in increased understanding of the genetic basis for PH, with recent discoveries such as TBX4 mutations specific for pediatric-onset pulmonary arterial hypertension (PAH) and SOX17 related to congenital heart disease–associated PAH. In addition to potential genetic underpinnings, PAH risk and clinical presentation in children with congenital heart disease may vary by cardiac condition, such as single-ventricle physiology or transposition of the great arteries. Growth and development of the pulmonary vasculature likely plays a role in all pediatric PH, which is highlighted by the disruption of normal lung growth in patients with PH related to prematurity and developmental lung disease. These diverse pediatric genotypes and phenotypes underscore a need for an individualized approach to diagnose and treat the complex pediatric PH population. Magnetic resonance imaging (MRI) is increasingly being used to improve clinical characterization of PH in children, with recent identification of specific MRI biomarkers associated with PH severity and outcomes. While much progress has been made, additional understanding of the important genetic causes and developmental concepts in pediatric PH is needed to develop a precision medicine approach to diagnosis and treatment of children with PH.

First-in-child use of the oral soluble guanylate cyclase stimulator riociguat in pulmonary arterial hypertension

Riociguat has been approved for use in adults with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension. No clinical data on its therapeutic use in children with PAH are currently available. We report the case of a now four-year-old boy who initially presented at the age of 10 months with suprasystemic pulmonary hypertension (PH) and right ventricular (RV) failure, vomiting, peripheral cyanosis, and failure to thrive. Cardiac catheterization revealed severe PAH. At radiologic suspicion of interstitial lung disease, repeated CT scan and an open lung biopsy were performed but could not clarify the entity of PAH. Given the demonstrated vasoreactivity, the boy was started on the calcium channel blocker amlodipine, in combination with the endothelin-1 receptor antagonist bosentan. Two years later, based on persistently systemic PAH with lost vasoreactivity, PAH therapy was changed to bosentan and phosphodiesterase-5 inhibitor sildenafil. No significant improvement on the aforementioned therapy was seen, so that the patient was referred to our institution. Invasive hemodynamic evaluation showed suprasystemic PAH and marked acute vasoreactivity (PAP 127/103/83 mmHg, PVRi 23.48 WU·m² and PVR/SVR ratio 1.59 at baseline vs. PVRi 5.89 WU·m² and PVR/SVR ratio 0.93 under O₂/NO). Subsequently, we switched the patient from sildenafil to riociguat. After six months on bosentan/riociguat, the patient showed a marked decrease in PVR/SVR and transpulmonary pressure gradients, in RV hypertrophy, PA acceleration time, and left ventricular-eccentricity index. Clinically, the patient improved in pediatric functional class from 2/3 to 1. In conclusion, off-label use of oral riociguat may be considered in selected children with severe PAH.

Diagnostics in Children and Adolescents with Suspected or Confirmed Pulmonary Hypertension

We provide a practical approach on the initial assessment and diagnostic work-up of children and adolescents with pulmonary hypertension (PH). Transthoracic echocardiography (TTE) often serves as initial study tool before invasive cardiac catheterization. Misinterpretation of TTE variables may lead to missed or delayed diagnosis with devastating consequences, or unnecessary invasive diagnostics that have inherited risks. In addition to clinical and biochemical markers, serial examination of patients with PH using a standardized TTE approach, determining conventional and novel echocardiographic variables, may allow early diagnosis and treatment in paediatric PH. Cardiac magnetic resonance imaging and computed tomography represent important non-invasive imaging modalities, that together with TTE may enable comprehensive assessment of ventricular function and pulmonary hemodynamics. Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterization laboratory is still the gold standard for the diagnosis of PH and pulmonary hypertensive vascular disease (PHVD) in children and for the initiation of specific PH therapy. We suggest the regular assessment of prognostic TTE variables as part of a standardized approach for initial diagnosis of children with PH. Overreliance on any single TTE variable should be avoided as it detracts from the overall diagnostic potential of a standardized TTE examination for PH.

First-in-child use of the oral selective prostacyclin IP receptor agonist selexipag in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a complex disease with a poor prognosis. Selexipag is a selective prostacyclin receptor agonist with vasodilatory, anti-proliferative, anti-inflammatory, and pro-angiogenic properties. However, no clinical data on its therapeutic use in children with PAH are currently available. Here, we report the case of a 12-year-old girl who presented in World Health Organization (WHO) functional class III and right ventricular (RV) failure with recurrent syncope, dizziness, and progressive fatigue for two years. Cardiac catheterization revealed severe precapillary PAH: mean right atrial pressure (RAP) = 10-13 mmHg, right ventricular end-diastolic pressure (RVEDP) = 13 mmHg, left ventricular end-diastolic pressure (LVEDP) = 7 mmHg, mean pulmonary arterial pressure (PAP) = 81 mmHg, and mean aorta ascendens pressure = 89 mmHg. The pulmonary vascular resistance index (PVRi) was 25.2 WU × m². An oral combination therapy was started with a phosphodiesterase type 5 inhibitor (sildenafil 3 × 20 mg) and an endothelin-1 receptor antagonist (bosentan 2 × 62.5 mg). No significant clinical/hemodynamic improvement was seen after nine months of dual therapy, so that the patient was transferred to our institution. We agreed upon the off-label add-on use of oral selexipag. Within ten days, we up-titrated selexipag to a final (max. adult) dose of 1600 mcg twice daily. After six months, the patient had: (1) decrease in PVR index, pulmonary artery acceleration time, RAP, RVEDP, right atrial/RV size; (2) re-gain of vasoreactivity; and (3) improvement of cardiac index, 6-minute walking distance, functional class, body weight, and CAMPHOR score. Our encouraging results suggest the consideration of off-label use of oral selexipag in children with severe PAH, preferably in a protocol-driven prospective study.

A review of pediatric pulmonary hypertension with new guidelines

This study aims to review pediatric pulmonary hypertension (PH) by comparing the guidelines of the European Society of Cardiology (ESC)/European Respiratory Society (ERS), the American Heart Association (AHA)/American Thoracic Society (ATS), and the European Pediatric Pulmonary Vascular Disease Network (EPPVDN). All three sets of guidelines define PH as having a mean pulmonary artery pressure of ≥25 mmHg and accept the validity of the World Health Organization (WHO) classification system. Every child with a high index of suspicion for PH should undergo an initial work-up of chest X-rays, electrocardiography, and echocardiography. The AHA/ATS guidelines emphasize the necessity of cardiac catheterization and hemodynamic studies. As mentioned in the AHA/ATS guidelines, the symptoms and tests that can detect PH include right ventricle failure, WHO functional class, syncope, echocardiography findings, hemodynamic data, brain natriuretic peptide (BNP)/N-terminal pro-BNP, the 6-min walk test, and cardiopulmonary exercise tests. The EPPVDN guidelines refer to positive acute vasoreactivity test results and growth as risk factors. All three guidelines highlight the importance of treating and following affected children in specialized centers and recommend calcium channel blockers as a first-line treatment in children (aged >12 months) who have a positive acute vasoreactivity test. Children with PH have distinct clinical features. In order to overcome the controversies related to the optimal management of pediatric PH, well-designed clinical studies should be carried out on a large cohort of affected children.

Echocardiographic Evaluation of Pulmonary Pressures and Right Ventricular Function after Pediatric Cardiac Surgery: A Simple Approach for the Intensivist

Pulmonary hypertension (PH) is diagnosed using cardiac catheterization and is defined as an elevation of mean pulmonary artery pressure (PAP) greater than 25 mmHg. Although invasive hemodynamics remains the gold standard and is mandatory for disease confirmation, transthoracic echocardiography (TTE) is an extremely useful non-invasive and widely available tool that allows for screening and follow-up, in particular, in the acute setting. TTE may be a valuable alternative, allowing for direct measurement and/or indirect assessment of PAP. Because of the complex geometric shape and pattern of contraction of the right ventricle (RV), as well as the inherent complexity of cardiac repair, no single view or measurement can provide definite information on RV function and PAP and/or pulmonary vascular resistance. In addition, specific training and expertise may be necessary to obtain the views and measurements required. Some simple measurements may be of help when rapid evaluation is mandatory and potentially life saving: the assessment of tricuspid and/or pulmonary valve regurgitant jet and the use of the Bernoulli equation allow for measurement of PAP. Measurements such as the analysis of the pulmonary Doppler wave flow, the septal curvature, or the eccentricity index, assessing ventricular interdependence, are useful for indirect assessment. A four-chamber view of the RV gives information on its size, hypertrophy, function (fractional area change), and tricuspid annular plane systolic excursion as an evaluation of the longitudinal function. Based on these simple measurements, TTE can provide detection of PH, measurement or estimation of PAP, and assessment of cardiac function. TTE is also of importance in follow up of PH as well as providing an assessment of therapeutic strategies in the postoperative setting of cardiac surgery. However, PAP may be misleading as it is dependent on cardiac output and requires accurate measurements. In the presence of residual lesions, analyses of some Doppler measurements may be misleading and not reflect real PAP. Should the TTE evaluation reveal non-conclusive, invasive hemodynamics remains the gold standard.

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.

Genetic testing and blood biomarkers in paediatric 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

Childhood-onset pulmonary arterial hypertension (PAH) is considered complex and multifactorial, with relatively poor estimates of the natural history of the disease. Strategies allowing earlier detection, establishment of disease aetiology together with more accurate and sensitive biomarkers could enable better estimates of prognosis and individualise therapeutic strategies. Evidence is accumulating that genetic defects play an important role in the pathogenesis of idiopathic and hereditary forms of PAH. Altogether nine genes have been reported so far to be associated with childhood onset PAH suggesting that comprehensive multigene diagnostics can be useful in the assessment. Identification of disease-causing mutations allows estimates of prognosis and forms the most effective way for risk stratification in the family. In addition to genetic determinants the analysis of blood biomarkers are increasingly used in clinical practice to evaluate disease severity and treatment responses. As in genetic diagnostics, a multiplex approach can be helpful, as a single biomarker for PAH is unlikely to meet all requirements. This consensus statement reviews the current evidence for the use of genetic diagnostics and use of blood biomarkers in the assessment of paediatric patients with PAH.

Pulmonary hypertension associated with acute or chronic lung diseases in the preterm and term neonate and infant. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Persistent pulmonary hypertension of the newborn (PPHN) is the most common neonatal form and mostly reversible after a few days with improvement of the underlying pulmonary condition. When pulmonary hypertension (PH) persists despite adequate treatment, the severity of parenchymal lung disease should be assessed by chest CT. Pulmonary vein stenosis may need to be ruled out by cardiac catheterisation and lung biopsy, and genetic workup is necessary when alveolar capillary dysplasia is suspected. In PPHN, optimisation of the cardiopulmonary situation including surfactant therapy should aim for preductal SpO2between 91% and 95% and severe cases without post-tricuspid-unrestrictive shunt may receive prostaglandin E1 to maintain ductal patency in right heart failure. Inhaled nitric oxide is indicated in mechanically ventilated infants to reduce the need for extracorporal membrane oxygenation (ECMO), and sildenafil can be considered when this therapy is not available. ECMO may be indicated according to the ELSO guidelines. In older preterm infant, where PH is mainly associated with bronchopulmonary dysplasia (BPD) or in term infants with developmental lung anomalies such as congenital diaphragmatic hernia or cardiac anomalies, left ventricular diastolic dysfunction/left atrial hypertension or pulmonary vein stenosis, can add to the complexity of the disease. Here, oral or intravenous sildenafil should be considered for PH treatment in BPD, the latter for critically ill patients. Furthermore, prostanoids, mineralcorticoid receptor antagonists, and diuretics can be beneficial. Infants with proven or suspected PH should receive close follow-up, including preductal/postductal SpO2measurements, echocardiography and laboratory work-up including NT-proBNP, guided by clinical improvement or lack thereof.

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.

Hemodynamic assessment and acute pulmonary vasoreactivity testing in the evaluation of children with pulmonary vascular disease. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterisation laboratory remain the gold standard for the diagnosis of pulmonary hypertension (PH) and pulmonary hypertensive vascular disease. However, these measurements and the interpretation thereof are challenging due to the heterogeneous aetiology of PH in childhood and potentially confounding factors in the catheterisation laboratory. Patients with pulmonary arterial hypertension (PAH) associated with congenital heart disease who have a cardiovascular shunt need to undergo a completely different catheterisation approach than those with idiopathic PAH lacking an anatomical cardiovascular defect. Diagnostic cardiac catheterisation of children with suspected PH usually includes right and left heart catheterisation, particularly for the initial assessment (ie, at the time of diagnosis), and should be performed in experienced centres only. Here, we present graded consensus recommendations for the invasive evaluation of children with PH including those with pulmonary hypertensive vascular disease and/or ventricular dysfunction. Based on the limited published studies and our own experience we suggest a structured catheterisation protocol and two separate definitions of positive acute vasoreactivity testing (AVT): (1) AVT to assess prognosis and indication for specific PH therapy, and (2) AVT to assess operability of PAH associated with congenital heart disease. The protocol and the latter definitions may help in the systematic assessment of these patients and the interpretation of the obtained data. Beyond an accurate diagnosis in the individual patient, such a structured approach may allow systematic decision making for the initiation of a specific treatment and may assist in estimating disease progression and individual prognosis.

Diagnostics, monitoring and outpatient care in children with suspected pulmonary hypertension/paediatric pulmonary hypertensive vascular disease. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Pulmonary hypertension (PH) is a condition of multiple aetiologies with underestimated prevalence and incidence. Indeed, despite access to modern therapies, pulmonary hypertensive vascular disease (PHVD) remains a progressive, usually life-limiting condition, severely impacting on the patients' well-being. We herein provide practical, expert consensus recommendations on the initial diagnostic work-up, clinical management and follow-up of children and adolescents with PH/PHVD, including a diagnostic algorithm. The major topics and methods that need to be tailored and put into context of the individual patient include PH classification, clinical signs and symptoms, basic diagnostic and advanced imaging measures (ECG, chest X-ray, transthoracic echocardiography, cardiac magnetic resonance, chest CT angiography, cardiac catheterisation, ventilation-perfusion lung scan, abdominal ultrasound), lung function tests, 6 min walk and cardiopulmonary exercise testing, sleep study (polysomnography), laboratory/immunological tests, considerations for elective surgery/ general anaesthesia, physical education and exercise, flying on commercial airplanes, vaccinations, care of central intravenous lines and palliative care. Due to the complexity of PH/PHVD, the clinical care has to be multidisciplinary and coordinated by a dedicated specialist paediatric PH centre, not only to decrease mortality but to allow children with PH/PHVD to reach a reasonable quality of life.