Pulmonary hypertension in children with congenital heart disease (PAH-CHD, PPHVD-CHD). Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Hybrid treat-and-repair strategy for large patent ductus arteriosus: a proof-of-concept case report

Background

In cases of atrial septal defect with pulmonary arterial hypertension (PAH), a treat-and-repair strategy that adopts pulmonary vasodilator therapy and subsequent defect closure is postulated to be effective. However, this strategy has not been applied to the large patent ductus arteriosus (PDA) with PAH.

Case summary

A 10-year-old girl with trisomy 21 was referred to our hospital for the treatment of a large PDA with PAH. Cardiac catheterization and angiography revealed a type C tubular PDA with a minimal diameter of 8.1 mm, an increase in mean pulmonary artery pressure (mPAP) of 60 mmHg, a ratio of pulmonary to systemic blood flow (Qp/Qs) of 2.7, and pulmonary artery resistance (Rp) of 7.1 U/m2. Because she was categorized in the grey zone for operability, we adopted a hybrid treat-and-repair strategy in which palliative surgical duct banding was performed before pulmonary vasodilator therapy to prevent excessive pulmonary blood flow and was followed by transcatheter closure of the PDA. Postoperatively, we confirmed the flow-restricted duct with a minimal diameter of 3.3 mm, decreased Qp/Qs 1.38, high mPAP 40 mmHg, and Rp 7.3 U/m2. Six months after treatment with macitentan and tadalafil, we confirmed a decrease in Rp 4.1 U/m2 as well as low Qp/Qs 1.12, which was low enough for the duct occlusion. The transcatheter occlusion of the surgically created type A conical duct was easily and safely performed. In the mid-term follow-up, favourable haemodynamics and improved exercise were confirmed.

Discussion

This is the first proof-of-concept case report to show the successful hybrid treat-and-repair strategy for large PDA, which warrants further investigation.

Right Atrial Strain in Pediatric Pulmonary Hypertension-A Prospective Observational Study

Right ventricular (RV) afterload due to elevated pulmonary arterial (PA) pressure in pulmonary hypertension (PH) causes long-term right atrial (RA) remodeling and dysfunction. RA function has been shown to correlate with PA pressures and outcome in both adult and pediatric patients with PH. We studied the role of RA strain in estimating PA pressures in congenital heart disease (CHD)-associated PH. Children below 12 years undergoing elective repair of CHD with left-to-right shunts and echocardiographic evidence of PH were included. RA reservoir, conduit and contractile strain along with conventional measures of RV function and PA pressure were measured using transthoracic echocardiography after induction of anaesthesia. Pre-and post-repair invasive PA pressures were measured after surgical exposure. 51 children with a median age of 24 months (range 4-144 months) were included, most of whom were undergoing VSD closure. Contractile RA strain showed good correlation with pre-repair systolic PA pressure in mmHg (r = 0.59, 95%CI 0.37-0.75) or expressed as a percentage of SBP (r = 0.67, 95%CI 0.49-0.80). It also predicted persistent postoperative PH as well as pre-repair pulmonary artery acceleration time and right ventricular systolic pressure measured from tricuspid regurgitation jet. The trends of correlation observed suggest a possible prognostic role of RA strain in ACHD with PH and potential utility in its echocardiographic assessment. The observed findings merit deeper evaluation in larger cohorts.

Pulmonary Hypertension in Adult Congenital Heart Disease-Related Heart Failure

Already a challenging condition to define, adult congenital heart disease (ACHD) -associated heart failure (HF) often incorporates specific anatomies, including intracardiac and extracardiac shunts, which require rigorous diagnostic characterization and heighten the importance of clinicians proactively considering overall hemodynamic impacts of using specific therapies. The presence of elevated pulmonary vascular resistance dramatically increases the complexity of managing patients with ACHD-HF. Total circulatory management in patients with ACHD-HF requires input from multidisciplinary care teams and thoughtful and careful utilization of medical, interventional, and surgical approaches.

A Meta-Analysis of Atrial Septal Defect Closure in Patients With Severe Pulmonary Hypertension: Is There a Room for Poking Holes Amid Debate?

Severe pulmonary arterial hypertension (PAH) associated with atrial septal defect (ASD) poses a challenge to a closure of ASD, particularly severe PAH that persists even after pharmacological therapeutic strategy. Our study was aimed to evaluate this matter. A systematic literature search from several databases was conducted up until August 1st, 2023. A meta-analysis was undertaken on studies that reported hemodynamic measurements in ASD patients with severe PAH before and after closure. The primary objectives were the extent of improvement in all hemodynamic parameters following closure, and the secondary outcomes were major adverse cardiac events (MACEs) during follow-up. Our study comprised 10 studies with a total of 207 participants. Patients were divided into treat-and-repair and straight-to-repair groups based on the therapeutic strategy. Meta-analysis of all studies demonstrated significant improvement in mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), pulmonary vascular resistance index (PVRI), 6-minutes walking distance (6MWD), and lower prevalence of World Health Organization functional classes (WHO fc), particularly in the treat-and-repair strategy subgroup. Additionally, merely 4 of the 156 individuals died from cardiac causes, and only 1 required rehospitalization, indicating a low likelihood of MACEs arising. Our new findings support the notion that effective shunt closure can improve various hemodynamic parameters in carefully chosen patients with noncorrectable ASD-PAH. Further large and prospective observational studies are still warranted to validate these findings.

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Prognostic Implication of Pulmonary Arterial Pressure in Surgical Repair of Predominantly Congenital Mitral Valve Regurgitation-Based Intracardiac Abnormalities

INTRODUCTION

Knowledge is limited regarding the significance of pulmonary arterial pressure (PAP) in predominantly congenital mitral valve regurgitation (MR)-based intracardiac abnormalities.

METHODS

From a prospective cohort, we included 200 patients with congenital MR regardless of other associated intracardiac abnormalities (mean age 60.4 months, 67% female, systolic PAP (sPAP) 54.2 mm Hg) surgically repaired in 2012-2019 and followed up to 2020 (median 30.0 months). Significant pulmonary hypertension (PH) was defined as sPAP >50 mm Hg at rest or mean PAP >25 mm Hg on right heart catheterization. By perioperative sPAP changes, patients were stratified as group I (pre-normotension to post-normotension), group II (pre-hypertension to post-normotension), or group III (pre-hypertension to post-hypertension). Primary outcomes were the recurrence of MR (defined as the regurgitation grade of moderate or greater) and the progression of MR (defined as any increase in the magnitude of regurgitation grade after surgery). Cox proportional hazard and Kaplan-Meier curve were performed.

RESULTS

There was no association between preoperative PH and the recurrent MR (adjusted hazard ratios [aHR]: 1.146 [95% CI: 0.453-2.899]) and progressive MR (aHR: 1.753 [95% CI: 0.807-3.804]), respectively. There were no significant differences among group I, group II, and group III in the recurrent MR but in the progressive MR. A dose dependency was identified for preoperative sPAP with recurrent MR (aHR: 1.050 [95% CI: 1.029-1.071]) and progressive MR risks (aHR: 1.037 [95% CI: 1.019-1.055]), respectively.

CONCLUSIONS

Preoperative higher sPAP is associated with worse outcomes, warranting heightened attention to the identification of perioperative sPAP.

Pulmonary hypertension in remote and disadvantaged population: overcoming unique challenges for improved outcomes

Pulmonary hypertension (PH) is a common and debilitating medical condition with high mortality. PH research has traditionally focused on pulmonary arterial hypertension and its management in expert PH centres. Other forms of PH such as PH associated with cardiac or respiratory disease are more common, less well-understood and associated with higher mortality. Epidemiology of PH in disadvantaged, remote and rural regions, remains largely undocumented. In this review, we discuss the unique challenges in identifying PH in rural and disadvantaged populations using the Top End region of the Northern Territory of Australia as an example. We propose a simple diagnostic approach, ideally suited to regions where resource allocation is scarce, using clinical skills, echocardiography, and an escalation algorithm. The brief history, epidemiology and current literature on PH are summarised to inform the busy clinicians. We highlight two case examples from the Top End to illustrate the challenges and potential solutions.

A North American, single-center experience implanting fenestrated atrial devices and atrial flow regulators into a heterogeneous group of pediatric pulmonary hypertension patients

INTRODUCTION

The clinical deterioration commonly experienced by pediatric patients with pulmonary arterial hypertension (PAH) has motivated a shift in the treatment of pulmonary hypertension (PH) through innovations in surgical salvage interventions. The Occlutech fenestrated atrial septal defect (FASD) Occluder and the atrial flow regulator (AFR), which provides a protective, atrial-level shunt during hypertensive crises, have found an important role in treating pediatric patients with PAH. Other groups of pediatric patients with PH may also benefit from a similar protective physiology. The primary aim of this work is to present a single center's experience with AFR and FASD devices for managing a heterogeneous group of pediatric PH patients. A secondary goal is to identify hemodynamic changes and complications following device implantation.

MATERIALS AND METHODS

We performed a retrospective review of all pediatric PH patients who, after being found suitable, either successfully or unsuccessfully received an FASD or AFR device between January 2015 and December 2021 at the Stollery Children's Hospital in Edmonton, Canada.

RESULTS

Fourteen patients (eight female) with a median age of 4.6 (range 0.3-17.9) years and a median body mass index of 15.1 (Q₁ = 13.8, Q₃ = 16.8) kg/m² underwent device implantation: five received FASDs, eight received AFRs, and one was ultimately unable to receive an implant due to thrombosed iliac vessels and required surgical intervention. Of the fourteen patients, seven were in group 1 (PAH), one was in group 3 (lung disease), and six were in group 5 (primarily pulmonary hypertension vascular disease) under the World Symposium PH classification. All patients were on mono-, dual-, or triple-drug PH therapy. Device stabilization was not possible for two patients, who then required a repeat catheterization. Of the group 1 patients, three AFR and three FASD implants were successful, while one FASD implant was unsuccessful due to thrombosed vessels. At a six-month clinical assessment, all group 1 patients had patent devices and improved WHO FCs.

CONCLUSION

This work presents a single center's experience with AFR and FASD implants in a heterogeneous group of fourteen pediatric patients with severe PH. This treatment strategy is novel in the pediatric population and so this work provides momentum for future studies of interventional cardiac catheterization procedures for pediatric patients with PH. Further collaborations are required to develop criteria to identify ideal pediatric candidates and optimally time interventions in order to maximize the benefits of this treatment.

The interplay between pressure, flow, and resistance in neonatal pulmonary hypertension

Pulmonary hypertension, conventionally defined by absolute pulmonary artery pressure, is the result of a range of diagnoses that can result in clinical problems in neonatal practice. Causes include persistent pulmonary hypertension of the newborn, congenital heart disease, and left heart dysfunction, as well as the normally high pulmonary artery resistance in neonates. Elucidating the cause of pulmonary hypertension is vital to guide appropriate management. A first principles approach based on hemodynamic calculations provides a framework for the diagnostic work up and subsequent therapy. Central to this is the equation 'pressure = flow x resistance' and knowledge of factors contributing to flow and resistance and their impact on pulmonary artery pressure. While formal, accurate, calculation of each element is usually not required or deliverable in small infants, clinical and echocardiographic parameters, combined with an understanding of the interplay between pressure, flow, and resistance, significantly improves the assessment and management of neonatal pulmonary hemodynamics.

A systematic review of clinical study evidence for pulmonary vasodilator therapy following surgery with cardiopulmonary bypass in children with CHD

OBJECTIVES

Complications from pulmonary hypertension are one of the leading contributors to morbidity and mortality post-cardiopulmonary bypass surgery in children with CHD. Pulmonary vasodilator therapies are commonly used post-operatively, but the optimal target patient population, therapy choice, timing of therapy initiation, and duration of therapy are not well defined.

METHODS

We used PubMed and EMBASE to identify studies from 2000 to 2020 investigating the use of pulmonary vasodilator therapy post-cardiopulmonary bypass in children aged 0-18 years. To ensure eligibility criteria, studies were systematically reviewed by two independent reviewers.

RESULTS

We identified 26 studies of 42,971 children across four medication classes; 23 were single centre, 14 were prospective, and 11 involved randomisation (four of which employed a placebo-control arm). A disproportionate number of children were from a single retrospective study of 41,872 patients. Definitions varied, but change in pulmonary haemodynamics was the most common primary outcome, used in 14 studies. Six studies had clinical endpoints, with mortality the primary endpoint for two studies. Treatment with inhaled nitric oxide, iloprost, and sildenafil all resulted in improved haemodynamics in specific cohorts of children with post-operative pulmonary hypertension, although improved outcomes were not consistently demonstrated across all treated children. Iloprost may be a cheaper alternative to inhaled nitric oxide with similar haemodynamic response.

CONCLUSION

Studies were predominantly single-centre, a control arm was rarely used in randomised studies, and haemodynamic endpoints varied significantly. Further research is needed to reduce post-operative morbidity and mortality from pulmonary hypertension in children with CHD.

Post-operative course of pulmonary artery pressure after complete atrioventricular canal defect repair

Complete atrioventricular canal defect is a CHD associated with intra-cardiac shunting of blood, which can lead to irreversible changes in pulmonary vascular resistance and pulmonary artery hypertension if unrepaired. Patients with Trisomy 21 are at risk for early development of pulmonary artery hypertension if left uncorrected.1,2.

OBJECTIVES

The purpose of this study is to describe the evolution of pulmonary artery hypertension after repair of complete atrioventricular canal defect and to determine the time to normalisation of pulmonary artery pressure in both patients with and without Trisomy 21.

METHODS

This is a single centre, retrospective analysis of patients with complete atrioventricular canal defect admitted for surgical repair at the University of Maryland Medical Center from 2005 to 2015. T-test or Mann-Whitney test and Chi-Square or Fisher's exact tests were used to compare the two groups (patients with Trisomy 21 and those without). Repeated measures of analysis of variance and serial measurement analysis were performed.

RESULTS

Twenty-nine patients meeting the inclusion criteria underwent repair of complete atrioventricular defects during the study period. The right ventricular pressure estimate remained elevated over time and did not show a significant difference between the two groups. Right ventricular to systolic blood pressure ratios for all patients remained > 0.5 over the time periods assessed.

CONCLUSIONS

Our study suggests that in patients with complete atrioventricular canal defects, the right ventricular pressure remains elevated and does not normalise on echocardiograms performed up to one year after surgery, suggesting a sustained elevation in pulmonary vascular resistance.

Risk factors for acute kidney injury after pediatric cardiac surgery: a meta-analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality in both adults and children.

OBJECTIVES

This study aimed to identify clinical risk factors for AKI following cardiac surgery in the pediatric population.

DATA SOURCES

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020.

STUDY ELIGIBILITY CRITERIA

Studies were included if (1) the population consisted of pediatric patients (< 18 years old), (2) patients underwent cardiac surgery, (3) risk factors were compared between patients who developed AKI and those who did not, and (4) studies were prospective or retrospective observational studies or randomized controlled trials.

PARTICIPANTS AND INTERVENTIONS

Children undergoing pediatric cardiac surgery.

STUDY APPRAISAL AND SYNTHESIS METHODS

Random-effects meta-analysis was performed, comparing potential risk factors between pediatric patients who developed CS-AKI and those who did not.

RESULTS

Sixty-one publications including a total of 19,680 participants (AKI: 7257 participants; no AKI: 12,423 participants) were included from studies published between 2008 and 2020. The pooled estimated incidence of AKI was 34.3% (95% confidence interval 30.0-38.8%, I² = 96.8%). Binary risk factors that were significantly and consistently associated with AKI were the presence of pulmonary hypertension, cyanotic heart disease, univentricular heart, risk adjustment for congenital heart surgery 1 (RACHS-1) score ≥ 3, vasopressor use, cardiopulmonary bypass use, reoperation, and sepsis. Significant continuous risk factors included younger age, lower body weight, lower preoperative creatinine, higher preoperative estimated glomerular filtration rate (eGFR), higher RACHS-1 score, longer surgery time, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and higher red blood cell transfusion volume.

LIMITATIONS

Results are limited by heterogeneity and potential residual confounding.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Our meta-analysis identified clinical risk factors that are associated with AKI in children undergoing cardiac surgery. This might help clinicians anticipate and manage more carefully this population and implement standardized preventive strategies.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42021262699. A higher resolution version of the Graphical abstract is available as Supplementary information.

Ventricular assist device for Fontan: who, when and why?

PURPOSE OF REVIEW

Since the advent of the Fontan palliation, survival of patients with univentricular congenital heart disease has increased significantly. These patients will, however, ultimately develop heart failure requiring advanced therapies such as heart transplantation. As wait times are long, mechanical circulatory support (MCS) is an attractive therapy, both for bridge to transplantation and destination therapy in patients not suitable for transplantation. This review aims to summarize current thinking about how to determine which patients would benefit from a ventricular assist device (VAD), the optimal time for implantation and which device should be considered.

RECENT FINDINGS

VAD implantation in end-stage Fontan is still in its infancy; however, case reports and research interest have increased extensively in the past few years. Mortality is significantly higher than in noncongenital heart disease patients. Implantation in patients with primarily systolic dysfunction is indicated, whereas patients with increased transpulmonary gradient may not benefit from a single-VAD solution. When possible, implantation should occur prior to clinical decompensation with evidence of end-organ damage, as outcomes at this point are worse.

SUMMARY

Fontan patients demonstrating signs of heart failure should be evaluated early and often for feasibility and optimal timing of VAD implantation. The frequency of this procedure will likely increase significantly in the future.

[Morphological assessment of pulmonary vessels in pulmonary arterial hypertension associated with congenital heart disease]

Pulmonary vascular remodeling is the key structural alteration in pulmonary arterial hypertension associated with congenital heart disease (CHD). Changes in the pulmonary vessels in CHD generally occur in the inner and middle coats. This review considers the pathology of these changes and highlights some issues of a stereological approach to the morphometry of pulmonary vasculature. It also touches upon the issues of the morphology of pulmonary vessels in post-capillary and segmental pulmonary hypertension.

A guide to echocardiographic assessment in children and adolescents with pulmonary hypertension

While the current definition of pulmonary hypertension (PH) is still based on haemodynamic variables, transthoracic echocardiography is the most important diagnostic clinical tool for the first assessment and evaluation of a patient, in whom PH is suspected. In addition, it is the most important clinical modality in long term follow-up and the utility of echocardiography has widely been demonstrated in patients with PH. Echocardiography not only reveals the underlying cardiac morphology and diagnosis of any associated cardiac defects. In most patients with PH right ventricular (RV) pressure estimation is feasible. In addition, ventricular systolic and diastolic function, as well as ventricular-ventricular interactions of both ventricles can be assessed by using echocardiography. Maximizing the use of echocardiography by reporting several measures to gain information and quantitatively describe the parameters, that are linked to prognosis, seem particularly appealing in these children, in whom other advanced imaging modalities requiring anaesthesia is associated with a considerable risk. Herein we provide a practical approach and a concise and clinically applicable echocardiographic guidance and present basic variables, which should be obtained at any assessment. Moreover, we present additional advanced echocardiographic measures, that can be applied in a research or clinical setting when progressive PH needs a deeper insight to assess heart function, estimation of pulmonary artery pressures among others, by echocardiography. Finally, clinically relevant studies in view of the prognostic properties with a focus on the most important echocardiographic variables in pediatric PH are summarized.

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.

Against all odds-late repair of multiple shunt lesions in a patient with Down syndrome: a case report

Background

Children with congenital heart defects (CHD) usually undergo elective surgical repair of haemodynamically relevant shunt lesions within the first year of life. Due to susceptibility for pulmonary arterial hypertension (PAH) in patients with Down syndrome, repair is usually aimed for no later than 6 months of life. However, with rising immigration from developing countries to Europe, more patients with unrepaired CHD are diagnosed at a later age. Anatomical repair may be precluded, when advanced pulmonary vascular disease has been established.

Case summary

We report a 39-month-old male patient with Down syndrome with a large non-restrictive perimembranous ventricular septal defect, a large patent ductus arteriosus, and a secundum-type atrial septal defect with a prominent left-to-right shunting. Haemodynamic assessment revealed only a mild increase of pulmonary artery pressures (mPAP) with low pulmonary vascular resistance index (PVRi). Vasodilator testing led to a further increase of the left-to-right shunt and decrease of PVRi, suggesting operability. After careful consideration, the patient underwent complete surgical repair with a good post-operative clinical outcome. Cardiac catheterization 6 months after corrective repair showed a normal mPAP. No signs of PAH have been detected in the medium-term follow-up.

Discussion

Expertise, increased physician awareness, and a thorough pre-operative multidisciplinary evaluation are paramount to determine the best treatment approach for patients, who may present late with multiple shunts, and—in our case—underlying Down syndrome. Long-term close post-surgical follow-up in an expert centre is warranted to promptly diagnose and treat a possible late presentation of PAH appropriately.

Sildenafil's Early, Late Impact on Ventricular Septal Repair: Older Children Using the Double Patch

BACKGROUND

Delayed diagnosis in children with a ventricular septal defect (VSD) is common in developing countries. Consequently, they present with elevated pulmonary vascular resistance (PVR) and pulmonary arterial hypertension (PAH). We introduced the double-flap valve VSD patch closure technique (DFV) in 1996 to reduce early post- operative risk. Long-term results are presented herein.

METHODS

This is a retrospective single-institution study on DFV patients performed between 5/1996 and 7/2015. Beginning in 2005 all candidates for DFV received sildenafil pre-and post-operatively. Pre-operative catheterization data, operative, post-operative, hospital and follow-up data were analyzed.

RESULTS

Forty patients received the DFV surgery. Patient demographics were comparable between sildenafil and non-sildenafil groups. Lost to follow up 1/39 (2.6%). Early mortality: 1/40 (2.5%), late mortality: 1/38 (2.6%). Sildenafil improved pre-op saturation, improved pre-operative hemodynamics as well as shortened prost-operative ventilation time. In both groups abnormal hemodynamic parameters improved with 100% oxygen challenge. The median age at late follow-up was 26.3 years (20.9; 29.9[25%; 75% Intra-quartile range]) and the median time since operation was 19.2 years (11.4; 22.7). Current discharge survival was 97.3%. Patients with severe PAH in late follow-up was 18%. Multi-variate analysis revealed only baseline PVR/SVR ≥ 0.8 as a significant predictor of late severe PAH.

CONCLUSIONS

Our long-term follow-up demonstrates that 60% of the patients will achieve normal or near normal PA pressures. Furthermore, we have demonstrated that sildenafil improves. pre-operative hemodynamics and post-operate management. Children with VSD, elevated PVR and PAH should not be denied operation.

Transcatheter Closure of Atrial Septal Defect Associated With Pulmonary Artery Hypertension using Fenestrated Devices

In patients with pulmonary artery hypertension (PAH) associated with atrial septal defect (ASD), closure of ASD may carry significant risks. We aimed to evaluate the safety and efficacy of transcatheter closure of ASD in selected patients with PAH using a fenestrated device followed by pulmonary vasodilator therapy. During the 14.8-year period, 51 ASD patients (10 males, age 46 ± 18 years) with a mean pulmonary artery pressure (PAP) ≥ 35 mm Hg and/or systolic PAP ≥ 60 mm Hg, underwent closure with a fenestrated device. Of them, mean Qp/Qs ratio, systolic PAP and mean PAP were 2.6 ± 1.2, 73 ± 14 mm Hg, and 44 ± 8 mm Hg, respectively. A total of 35 patients received pulmonary vasodilator therapy. The New York Heart Association (NYHA) functional class improved at 3 to 6 months follow-up. (p < 0.001) Nineteen patients underwent repeated catheterization. A comparison of the hemodynamic parameters between baseline and repeated catheterization revealed significant decreases in both systolic and mean PAP (77 ± 11 vs 55 ± 14 mm Hg, p < 0.0001 & 48 ± 7 vs 37 ± 8 mm Hg, p = 0.001, respectively), pulmonary vascular resistance (PVR) (5.1 ± 2.3 vs 4.0 ± 1.7 WU, p = 0.011) and PVRi (7.7 ± 3.3 vs 6.2 ± 2.4 WU*m2, p = 0.024). After a follow-up period of 84 ± 45 months, 6 mortalities were noted in which 2 were due to cardiac causes. In conclusion, catheter closure of ASD in patients with PAH using a fenestrated device followed by vasodilator therapy is safe and effective.

Survival of Left-to-Right Shunt Repair in Children with Pulmonary Arterial Hypertension at a Tertiary Hospital in a Low-to-Middle-Income Country

Background

In low-to-middle-income countries, repair of the left-to-right shunts congenital heart disease (CHD) are often done with existing pulmonary arterial hypertension (PAH). Long-term outcomes data of this condition in either low-to-middle or high-income countries are limited. We conducted a study to evaluate the outcomes of children with PAH related to left-to-right shunt CHD who underwent surgical or transcatheter repair.

Methods

All cases of PAH related to left-to-right shunt CHD repairs from 2015-2018 were retrospectively reviewed with additional new patients who underwent repair within our study period (2019-2020). Cases with complex congenital heart disease and incomplete hemodynamic echocardiography or catheterization measurements were excluded. Kaplan-Meier curves, log-rank test, Cox regression with Firth's correction and restricted mean survival time were used for survival analysis.

Results

Of the 118 patients, 103 patients were enrolled and 15 patients were excluded due to complex congenital heart disease and missing hemodynamic measurements prior to repair. Overall, median age at intervention was 44 months, mPAP mean was 43.17 ± 16.05 mmHg and Pulmonary Vascular Resistance index (PVRi) mean was 2.84 ± 2.09 (WU.m2). Nine patients died after repair. The survival rate for patients with PAH-CHD at 1 day, 30 days and 1400 days (4 years) was 96.1%, 92.1%, and 91.0% respectively. Patients with persisting PAH after correction had -476.1 days (95% confidence interval [CI]: -714.4, -237,8) shorter survival over 4 years of follow up compared to patients with reversed PAH. PVRi was found to be the influencing covariate of the difference of restricted mean survival time between these groups.

Conclusion

In low-to-middle income settings, with accurate PAH reversibility assessment prior to intervention, repair of left-to-right shunt CHD with existing PAH in children has a favourable outcome. Inferior survival is found in patients with persistence of PAH. PVRi at baseline predicts between-group survival difference.

Pulmonary Hypertension in Acute and Chronic High Altitude Maladaptation Disorders

Alveolar hypoxia is the most prominent feature of high altitude environment with well-known consequences for the cardio-pulmonary system, including development of pulmonary hypertension. Pulmonary hypertension due to an exaggerated hypoxic pulmonary vasoconstriction contributes to high altitude pulmonary edema (HAPE), a life-threatening disorder, occurring at high altitudes in non-acclimatized healthy individuals. Despite a strong physiologic rationale for using vasodilators for prevention and treatment of HAPE, no systematic studies of their efficacy have been conducted to date. Calcium-channel blockers are currently recommended for drug prophylaxis in high-risk individuals with a clear history of recurrent HAPE based on the extensive clinical experience with nifedipine in HAPE prevention in susceptible individuals. Chronic exposure to hypoxia induces pulmonary vascular remodeling and development of pulmonary hypertension, which places an increased pressure load on the right ventricle leading to right heart failure. Further, pulmonary hypertension along with excessive erythrocytosis may complicate chronic mountain sickness, another high altitude maladaptation disorder. Importantly, other causes than hypoxia may potentially underlie and/or contribute to pulmonary hypertension at high altitude, such as chronic heart and lung diseases, thrombotic or embolic diseases. Extensive clinical experience with drugs in patients with pulmonary arterial hypertension suggests their potential for treatment of high altitude pulmonary hypertension. Small studies have demonstrated their efficacy in reducing pulmonary artery pressure in high altitude residents. However, no drugs have been approved to date for the therapy of chronic high altitude pulmonary hypertension. This work provides a literature review on the role of pulmonary hypertension in the pathogenesis of acute and chronic high altitude maladaptation disorders and summarizes current knowledge regarding potential treatment options.

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or–on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD.

Hemodynamic trajectories and outcomes in patients with pulmonary arterial hypertension

The relative pulmonary to systemic pressure ratio (mean pulmonary arterial pressure/mean arterial pressure) has been proven to be valuable in cardiac surgery. Little is known on the prognostic value of baseline and trajectory of mean pulmonary arterial pressure/mean arterial pressure in pulmonary arterial hypertension. Patients with confirmed idiopathic, familial, drug and toxins, or connective tissue disease-related pulmonary arterial hypertension and at least one complete right heart catheterization were included and prospectively followed-up for 5.9 ± 4.03 years. Correlates of the primary end point (i.e. death or lung transplant need) during follow-up were determined using Cox regression modeling. Results showed that among the 308 patients included, 187 had at least one follow-up catheterization (median time between catheterizations: 2.16 (1.16–3.19) years). In the total cohort (mean age 47.3 ± 14.9 years, 82.8% of female and 58.1% in New York Heart Association class 3 or 4), mean pulmonary arterial pressure/mean arterial pressure (1.38 (1.07–1.77)) was associated with outcome (p = 0.01). Mean pulmonary arterial pressure/mean arterial pressure was incremental to a basic model (including right atrial pressure, systolic blood pressure, New York Heart Association class 3 or 4, and connective tissue disease) for outcome prediction, while mean pulmonary arterial pressure was not. In the 187 patients with a follow-up catheterization, both delta mean pulmonary arterial pressure and delta mean pulmonary arterial pressure/mean arterial pressure were associated with outcome (1.32 (1.11–1.58) and 1.31 (1.1–1.57) respectively, p < 0.01). Mean pulmonary arterial pressure and mean pulmonary arterial pressure/mean arterial pressure were both incremental to the basic model, while worsening in mean pulmonary arterial pressure or mean pulmonary arterial pressure/mean arterial pressure did not reach significance. In conclusion, mean pulmonary arterial pressure/mean arterial pressure at baseline prognosticates long-term outcome with a significant, albeit modest, incremental value to basic variables.

The effect of distal pulmonary obstruction or elevated atrial pressures on pulmonary flow and pulmonary vascular disease: a mathematical flow circuit analogy model-based analysis

Background

Late presentation of large left to right shunts is a major problem in developing countries and evaluating the operability is a challenge during preoperative evaluation. The factors that determine the development and progression of the pulmonary vascular disease are still largely unknown, though there is evidence to show that increased pulmonary flow is the main contributing factor. We have found cases of operability despite late presentation of ventricular septal defect (VSD). In some of these cases, the reason for operability may lie in associations. We herein attempt to provide a mathematical explanation for their operability.

Aims and objectives

To assess the effect of different levels of obstruction and elevated ventricular end-diastolic pressure on pulmonary flow.

Materials and methods

Mathematical flow analogy models were constructed and analysed based on Ohm's law and the laws governing flow in series and parallel flow circuits.

Results

Any narrowing in the pulmonary circulation produces a reduction in pulmonary blood flow and the pulmonary to systemic blood flow ratio, irrespective of its position. This increases the systemic flow and blood pressure if the ventricular performance remains constant. A rise in ventricular end-diastolic pressure reduces the total cardiac output, pulmonary flow and systemic blood flow with a preserved pulmonary to systemic flow ratio. The absolute reduction in pulmonary flow will exceed the absolute reduction in systemic flow, with its ratio being in proportion to the ratio of systemic to pulmonary vascular resistance. However, a higher pressure will be transmitted distally in these settings. These mechanisms of flow reduction may prevent irreversible pulmonary vascular disease.

Conclusion

Distal pulmonary obstruction or elevated ventricular end-diastolic pressure can reduce pulmonary blood flow and may prevent irreversible pulmonary vascular disease. Clinical studies in this direction are recommended for validation.

Right ventricular end-systolic remodeling index in the assessment of pediatric pulmonary arterial hypertension. The European Pediatric Pulmonary Vascular Disease Network (EPPVDN)

BACKGROUND

Echocardiographic determination of the right ventricular end-systolic remodeling index (RVES RI) has clinical value for the assessment of pulmonary hypertension (PH) in adults. We aim to determine RVES RI values in pediatric PH and to correlate RVES RI data with echocardiographic variables and NYHA functional class (FC).

METHODS

Prospective echocardiography study in 49 children with PH. The 49 matched control subjects were chosen from 123 healthy children used to construct pediatric normal reference values. The associations with invasive hemodynamic variables were also investigated in a validation cohort of 12 PH children and matched controls.

RESULTS

RVES RI was increased in children with PH vs. healthy controls (1.45 ± 0.16 vs. 1.16 ± 0.06; p < 0.01; confirmed in the validation cohort). RVES RI was associated with invasive hemodynamic variables, i.e. the mean pulmonary artery pressure. RVES RI values increased with worsening NYHA-FC. The highest RVES RI values were observed in PH children with NYHA FC 3 (1.60 ± 0.12).

CONCLUSIONS

RVES RI is a useful indicator of RV remodeling and dilation in the setting of increased RV pressure load, especially when the degree of regurgitation of the tricuspid and pulmonary valves is insufficient to numerically estimate RV systolic pressure and mPAP, due to incomplete Doppler envelopes.

Pregnancy in adults with congenital heart disease

Congenital heart disease (CHD) is present in 0.8-0.9% of live births. Prevalence of CHD is constantly increasing during the last decades in line with the treatment options for patients ranging from the surgical as well to the interventional spectrum. Most of the women with underlying CHD reach adulthood due to excellent surgical and interventional treatment options and most of them desire pregnancy. In Western countries, maternal heart disease is the major cause of mortality during pregnancy, thus risk estimation should be therefore individualized depending on the underlying CHD, functional class and treatment options. Pre-pregnancy counselling is mandatory in all women, especially in patients with high risk but even in patients with low risk, a plan for labor and delivery should be outlined in a heart pregnancy team. This review addresses the key element of pre-counselling, planning and successful disease management in patients with CHD during pregnancy.

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.

Chronic dosing with metformin plus bosentan decreases in vitro pulmonary artery contraction from isolated arteries in adults with pulmonary hypertension

Introduction: Pulmonary arterial hypertension (PAH) specific drug therapy using bosentan has significantly improved quality of life and survival, although PAH is still an incurable disease. Recent studies suggest metformin may have additional treatment benefits in PAH. We therefore investigated in vitro pulmonary artery reactivity after combination therapy of bosentan and metformin in PAH patients as compared with bosentan monotherapy in a prospective, randomized study.

Methods: Adult patients with PAH associated with congenital heart defects (PAH-CHD) were randomised to receive bosentan (initially at 62.5 mg twice daily for 4 weeks and then 125 mg twice daily) for 3 months with or without the combination treatment of metformin (500 mg twice daily). Vessel reactivity of isolated pulmonary arteries was examined using a wire myograph.

Results: Phenylephrine (PE)-induced contractions of arteries in patients received combination therapy were significantly attenuated at concentrations of 3 × 10^-7 M, 10^-6 M and 3 × 10^-6 M, compared to those received bosentan monotherapy. After denudation, PE-induced contractions at concentrations of 3 × 10^-6 M and 10^-5 M were significantly decreased in the combination therapy group. AMP-activated protein kinase (AMPK) inhibitor compound C abrogated the inhibitory effects of metformin on PE-induced contractility. AMPK and eNOS phosphorylation in the pulmonary arteries of patients treated with combination therapy was increased compared to monotherapy (P < 0.05).

Conclusion: Adding metformin to bosentan therapy in patients with PAH-CHD decreased in vitro pulmonary artery contraction induced by PE, which is possibly related to increased AMPK phosphorylation.

2019 updated consensus statement on the diagnosis and treatment of pediatric pulmonary hypertension: The European Pediatric Pulmonary Vascular Disease Network (EPPVDN), endorsed by AEPC, ESPR and ISHLT

The European Pediatric Pulmonary Vascular Disease Network is a registered, non-profit organization that strives to define and develop effective, innovative diagnostic methods and treatment options in all forms of pediatric pulmonary hypertensive vascular disease, including pulmonary hypertension (PH) associated with bronchopulmonary dysplasia, PH associated with congenital heart disease (CHD), persistent PH of the newborn, and related cardiac dysfunction. The executive writing group members conducted searches of the PubMed/MEDLINE bibliographic database (1990-2018) and held face-to-face and web-based meetings. Ten section task forces voted on the updated recommendations, based on the 2016 executive summary. Clinical trials, meta-analyses, guidelines, and other articles that include pediatric data were searched using the term "pulmonary hypertension" and other keywords. Class of recommendation (COR) and level of evidence (LOE) were assigned based on European Society of Cardiology/American Heart Association definitions and on pediatric data only, or on adult studies that included >10% children or studies that enrolled adults with CHD. New definitions by the World Symposium on Pulmonary Hypertension 2018 were included. We generated 10 tables with graded recommendations (COR/LOE). The topics include diagnosis/monitoring, genetics/biomarkers, cardiac catheterization, echocardiography, cardiac magnetic resonance/chest computed tomography, associated forms of PH, intensive care unit/lung transplantation, and treatment of pediatric PH. For the first time, a set of specific recommendations on the management of PH in middle- and low-income regions was developed. Taken together, these executive, up-to-date guidelines provide a specific, comprehensive, detailed but practical framework for the optimal clinical care of children and young adults with PH.

EXPRESS: Parameters associated with outcome in pediatric patients with congenital heart disease and pulmonary hypertension subjected to combined vasodilator and surgical treatments

Management of pediatric pulmonary hypertension associated with congenital heart disease (PHT-CHD) is challenging. Some patients have persistently elevated pulmonary artery pressure (PAP) after cardiac surgery, an undesired condition that is difficult to predict. We investigated the value of clinical, hemodynamic, and histopathological data in predicting the outcome in a prospective cohort. Patients with PHT-CHD received sildenafil orally pre- and postoperatively for six months and then were subjected to a catheter study. Thirty-three patients were enrolled (age range = 4.6–37.0 months). Pulmonary vascular resistance (PVR) was 4.9 (range = 3.9–7.2) Wood units × m2 (median with IQR). Twenty-two patients had a ≥ 20% decrease in PVR and pulmonary-to-systemic vascular resistance ratio (PVR/SVR) in response to inhaled nitric oxide (NO). The response was directly related to the degree of medial hypertrophy of pulmonary arterioles (P  < 0.05) (morphometric analysis, intraoperative lung biopsy). Subsequently, five of the non-responders had a ≥ 30% increase in pulmonary blood flow in response to sildenafil (3.0 [2.0–4.0] mg/kg/day). Six months after surgery, PAP and PVR were significantly lower (P  < 0.001 vs. baseline), even in seven patients with Heath-Edwards grade III/IV pulmonary vascular lesions (P  = 0.018), but still abnormal in 12 individuals (>25 mmHg and >3.0 U × m2, respectively). A preoperative PVR/SVR of ≥24% during NO inhalation and a wall thickness of arteries accompanying respiratory bronchioli of ≥4.7 (Z score) were identified, respectively, as risk and protection factors for abnormal postoperative hemodynamics (hazard ratio [95% CI] = 1.09 [1.01–1.18], P  = 0.036; and 0.69 [0.49–0.98], P  = 0.040, respectively). Thus, in PHT-CHD patients receiving oral sildenafil pre- and post-surgical repair of cardiac lesions, mid-term postoperative outcome is predictable to some extent.

How to evaluate patients with congenital heart disease-related pulmonary arterial hypertension

INTRODUCTION

Patients with congenital heart disease (CHD), who develop pulmonary arterial hypertension (PAH), live longer, and have better quality of life compared to the past due to PAH-specific therapy and improved tertiary care. Areas covered: Clinical examination, objective assessment of functional capacity, natriuretic peptide levels, cardiac imaging, and hemodynamics all play a pivotal role in the evaluation, general care, and management of PAH-specific therapy. This review discusses the epidemiology and pathophysiology of PAH-CHD and provides hints for the optimal evaluation of these patients. Expert commentary: Further research should be performed in the field of PAH-CHD, as there are many of areas lacking evidence that should be addressed in the future. Networking, especially among the tertiary expert centers, could play a key role in this direction.

The impact of trisomy 21 on treatment modalities and outcome in adults with congenital heart disease in Switzerland

Trisomy 21 (T21) is associated in 40-45% of cases with heart defects, most commonly shunt lesions. These defects, if not repaired, can lead to irreversible shunt-induced pulmonary hypertension (i.e. Eisenmenger syndrome [ES]). In ES patients, intracardiac repair is no longer possible, but selective pulmonary vasodilators may increase exercise capacity and improve prognosis. This study aimed to estimate the prevalence of cardiac defects and ES in adult T21 patients and to assess the impact of T21 on treatment modalities and outcome in ES patients. A questionnaire was sent to 6906 Swiss physicians inviting them to indicate the number of adults with T21 under their care (survey report). We also analyzed all adults with ES (with and without T21) included in the Swiss Adult Congenital HEart disease Registry (SACHER) and studied the impact of T21 on the use of selective pulmonary vasodilators and survival. In the survey, 348 physicians cared for 695 adult T21 patients. Overall, 24% of T21 survey patients were known to have a cardiac defect, one in four with a defect had developed ES and 13% of those with ES were on specific pulmonary vasodilators. In SACHER, ES was present in 2% of adults with congenital heart disease and selective pulmonary vasodilators were used in 68% of ES patients with T21. In SACHER, survival during follow-up was worse with higher nt-proBNP levels (hazard ratio [HR] = 1.15 per 1000 units, 95% confidence interval [CI] = 1.02-1.29) and lower left ventricular ejection fraction (HR = 1.07 per percent decrease, 95% CI = 1.01-1.13). Age at inclusion and T21 did not affect survival. The prevalence of cardiac defects in adults with T21 in Switzerland is half the prevalence in children. T21 is over-represented among adults with ES. Raised awareness of the therapeutic options for T21 patients with ES is warranted.

Metformin added to bosentan therapy in patients with pulmonary arterial hypertension associated with congenital heart defects: a pilot study

Pulmonary arterial hypertension (PAH) is a common complication of a congenital heart defect (CHD). Recent studies suggest metformin may be a potential drug to improve cardiac function in PAH. A pilot study was conducted to investigate the efficacy of short-term treatment with a combination regimen consisting of bosentan and metformin in PAH-CHD patients as compared with bosentan monotherapy in a prospective, randomised study.

Patients with PAH-CHD were randomised to receive bosentan (initially at 62.5 mg twice daily for 4 weeks and then 125 mg twice daily) for 3 months with or without the combination treatment of metformin (500 mg twice daily).

93 patients were enrolled to bosentan monotherapy (n=48) or bosentan/metformin combination treatment (n=45). After 3 months, both treatments significantly improved World Health Organization functional class, 6-min walking distance (6MWD), N-terminal pro-brain natriuretic peptide and right heart haemodynamic parameters. The improvements in 6MWD and pulmonary vascular resistance index were significantly greater in patients treated with combination therapy than in those who received monotherapy (mean±sd 95±136 versus 48±119 m (p=0.017) and −1.8±1.2 versus −1.2±1.3 Wood units per m² (p<0.001), respectively). Pulmonary endothelin (EDN)1 was significantly decreased after combination therapy (p=0.006). However, plasma EDN1 levels were not affected.

Combination therapy with bosentan and metformin in PAH-CHD patients provides improvements in important outcomes such as exercise capacity and pulmonary haemodynamics, compared with bosentan alone.

This study investigated, for the first time, the efficacy of a combination regimen consisting of bosentan and metformin in patients with pulmonary arterial hypertension associated with congenital heart defect as compared with bosentan monotherapyhttp://ow.ly/n4nJ30kT98d

Right ventricular base/apex ratio in the assessment of pediatric pulmonary arterial hypertension: Results from the European Pediatric Pulmonary Vascular Disease Network

BACKGROUND

Echocardiographic determination of RV end-systolic base/apex (RVES b/a) ratio was proposed to be of clinical value for assessment of pulmonary arterial hypertension (PAH) in adults.

HYPOTHESIS

We hypothesized that the RVES b/a ratio will be affected in children with PAH and aimed to correlate RVES b/a ratio with conventionally used echocardiographic and hemodynamic variables, and with New York Heart Association (NYHA) functional class.

METHODS

First we determined normal pediatric values for RVES b/a ratio in 157 healthy children (68 males; age range, 0.5-17.7 years). We then conducted an echocardiographic study in 51 children with PAH (29 males; age range, 0.3-17.8 years).

RESULTS

RVES b/a ratio was lower compared with age- and sex-matched healthy controls (P < 0.001). In children with PAH, RVES b/a ratio decreased with worsening NYHA class. RVES b/a ratio inversely correlated with RV/LV end-systolic diameter ratio (ρ = -0.450, P = 0.001) but did not correlate with RV systolic function parameters (eg, tricuspid annular plane systolic excursion) and correlated with cardiac catheterization-determined pulmonary vascular resistance index (ρ = -0.571, P < 0.001). ROC analysis unraveled excellent performance of RVES b/a ratio to detect PAH in children (AUC: 0.95, 95% CI: 0.89-1.00, P < 0.001).

CONCLUSIONS

The RVES b/a ratio decreased in children with PAH compared with age- and sex-matched healthy subjects. The RVES b/a ratio inversely correlated with both echocardiographic and hemodynamic indicators of increased RV pressure afterload and with NYHA class, suggesting that RVES b/a ratio reflects disease severity in PAH children.

Pulmonary hypertension in congenital heart disease

Pulmonary hypertension is defined as a mean pulmonary arterial pressure ≥25 mmHg. We focus on its relevance in congenital heart disease, reviewing pathophysiology, diagnosis and management. Pulmonary hypertension is a relatively common complication of congenital heart disease, with adult prevalence between 5 and 10%. A multifactorial cause is recognized, relating to the size and nature of cardiac defect as well as environmental and genetic factors. More complex disease is increasingly recognized rather than pure Eisenmenger complex. Remodeling of the pulmonary vascular bed causes increased pulmonary vascular resistance diagnosed by a collection of investigations including echocardiography, exercise testing, cardiac catheterization, MRI and CT scanning. Management employs disease-modifying medications which are now used with increasing benefit.

Echocardiographic Evaluation of Transitional Circulation for the Neonatologists

The hemodynamic changes during the first few breaths after birth are probably the most significant and drastic adaptation in the human life. These changes are critical for a smooth transition of fetal to neonatal circulation. With the cord clamping, lungs take over as the source of oxygenation from placenta. A smooth transition of circulation is a complex mechanism and primarily depends upon the drop in pulmonary vascular resistance (PVR) and increase in systemic vascular resistance (SVR). Understanding the normal transition physiology and the adverse adaptation is of utmost importance to the clinicians looking after neonates. It may have a significant influence on the presentation of congenital heart defects (CHDs) in infants. Bedside echocardiography may help in understanding the transition physiology, especially the hemodynamic changes and shunting across ductus arteriosus and foramen ovale, and it may play an important role in making judicious clinical decisions based upon the altered physiology.

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.

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.

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

: The European Paediatric Pulmonary Vascular Disease (PVD) Network is a registered, non-profit organisation that strives to define and develop effective, innovative diagnostic methods and treatment options in all forms of paediatric pulmonary hypertensive vascular disease, including specific forms such as pulmonary arterial hypertension (PAH)-congenital heart disease, pulmonary hypertension (PH) associated with bronchopulmonary dysplasia, persistent PH of the newborn, and related cardiac dysfunction.

METHODS

The writing group members conducted searches of the PubMed/MEDLINE bibliographic database (1990-2015) and held five face-to-face meetings with votings. Clinical trials, guidelines, and reviews limited to paediatric data were searched using the terms 'pulmonary hypertensioń' and 5-10 other keywords, as outlined in the other nine articles of this special issue. Class of recommendation (COR) and level of evidence (LOE) were assigned based on European Society of Cardiology/American Heart Association definitions and on paediatric data only, or on adult studies that included >10% children.

RESULTS

A total of 9 original consensus articles with graded recommendations (COR/LOE) were developed, and are summarised here. The topics included diagnosis/monitoring, genetics/biomarker, cardiac catheterisation, echocardiography, cardiac magnetic resonance/chest CT, associated forms of PH, intensive care unit/ventricular assist device/lung transplantation, and treatment of paediatric PAH.

CONCLUSIONS

The multipaper expert consensus statement of the European Paediatric PVD Network provides a specific, comprehensive, detailed but practical framework for the optimal clinical care of children with PH.

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.