Repair of congenital heart disease with associated pulmonary hypertension in children: what are the minimal investigative procedures? Consensus statement from the Congenital Heart Disease and Pediatric Task Forces, Pulmonary Vascular Research Institute (PVRI)

Closing the gap between acceptable and ideal in catheterisation for paediatric and congenital heart disease-A global view

In recent issues of the Journal of the Society for Cardiovascular Angiography and Interventions and the Journal of the American College of Cardiology: Cardiovascular Interventions, Holzer and colleagues presented an Expert Consensus Document titled: "PICS / AEPC / APPCS / CSANZ / SCAI / SOLACI: Expert consensus statement on cardiac catheterization for pediatric patients and adults with congenital heart disease." This Expert Consensus Document is a massively important contribution to the community of paediatric and congenital cardiac care. This document was developed as an Expert Consensus Document by the Pediatric and Congenital Interventional Cardiovascular Society, the Association for European Paediatric and Congenital Cardiology, the Asia-Pacific Pediatric Cardiac Society, the Cardiac Society of Australia and New Zealand, the Society for Cardiovascular Angiography and Interventions, and the Latin American Society of Interventional Cardiology, as well as the Congenital Cardiac Anesthesia Society and the American Association of Physicists in Medicine.As perfectly stated in the Preamble of this Expert Consensus Document, "This expert consensus document is intended to inform practitioners, payors, hospital administrators and other parties as to the opinion of the aforementioned societies about best practices for cardiac catheterisation and transcatheter management of paediatric and adult patients with congenital heart disease, with added accommodations for resource-limited environments." And, the fact that the authorship of this Expert Consensus Document includes global representation is notable, commendable, and important.This Expert Consensus Document has the potential to fill an important gap for this patient population. National guideline documents for specific aspects of interventions in patients with paediatric heart disease, including training guidelines, do exist. However, this current Expert Consensus Document authored by Holzer and colleagues provides truly globally applicable standards on cardiac catheterisation for both paediatric patients and adults with congenital heart disease (CHD).Our current Editorial provides different regional perspectives from senior physicians dedicated to paediatric and congenital cardiac care who are practicing in Europe, the Asia-Pacific region, Latin America, Australia/New Zealand, and North America. Establishing worldwide standards for cardiac catheterisation laboratories for children and adults with CHD is a significant stride towards improving the quality and consistency of care. These standards should not only reflect the current state of medical knowledge but should also be adaptable to future advancements, ultimately fostering better outcomes and enhancing the lives of individuals affected by CHD worldwide.Ensuring that these standards are accessible and adaptable across different healthcare settings globally is a critical step. Given the variability in resources and infrastructure globally, the need exists for flexibility and tailoring to implement recommendations.The potential impact of the Expert Consensus Document and its recommendations is likely significant, but heterogeneity of healthcare systems will pose continuing challenges on healthcare professionals. Indeed, this heterogeneity of healthcare systems will challenge healthcare professionals to finally close the gap between acceptable and ideal in the catheterisation of patients with paediatric and/or congenital heart disease.

Current Management and Future Directions for Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Current management of patients with congenital heart disease has increased their survival into adulthood. This is accompanied by potential cardiac complications, including pulmonary hypertension associated with congenital heart disease (PAH-CHD). PAH-CHD constitutes a challenging subgroup of pulmonary hypertension and requires expert management to improve quality of life and prognosis. Novel agents have shown a significant improvement in morbidity and mortality in patients with pulmonary arterial hypertension. However, the long-term effects of these medications on PAH-CHD patients remain somewhat uncertain, necessitating treatment plans largely founded on the clinical experience of the healthcare providers. The aim of this review is to summarize the current evidence and future perspectives regarding treatment strategies for PAH-CHD to help better guide management of this complex disease.

Pulmonary arterial compliance in patients of CHD with increased pulmonary blood flow

INTRODUCTION

Pulmonary arterial compliance, the dynamic component of pulmonary vasculature, remains inadequately studied in patients with left to right shunts. We sought to study the pulmonary arterial compliance in patients with left to right shunt lesions and its utility in clinical decision-making.

MATERIALS AND METHODS

In this single-centre retrospective study, we reviewed cardiac catheterisation data of consecutive patients of left to right shunt lesions catheterised over one year. In addition to the various other parameters, pulmonary arterial compliance was calculated, as indexed pulmonary flow (Qpi) / (Heart rate × pulse pressure in the pulmonary artery). RC time was also calculated, as the product of pulmonary arterial compliance and pulmonary vascular resistance index. Patients were divided into "operable," "borderline," and "inoperable" based on the decision of the treating team, and the pulmonary arterial compliance values were evaluated in these groups to study if it can be utilised to refine the operability decision.

RESULTS

298 patients (Median age 16 years, 56% <18 years) with various acyanotic shunt lesions were included. Overall, the pulmonary arterial compliance varied with Qpi, pulmonary artery mean pressure, and pulmonary vascular resistance index, but did not vary with age, type of lesion, or transpulmonary gradients. The median pulmonary arterial compliance in patients with normal pulmonary artery pressure (Mean pulmonary artery pressure less than 20 mmHg) was 4.1 ml/mmHg/m2 (IQR 3.2). The median pulmonary arterial compliance for operable patients was 2.67 ml/mmHg/m2 (IQR 2.2). Median pulmonary arterial compliance was significantly lower in both inoperable (0.52 ml/mmHg/m2, IQR 0.34) and borderline (0.80 ml/mmHg/m2, IQR 0.36) groups when compared to operable patients (p < 0.001). A pulmonary arterial compliance value lower than 1.18 ml/mmHg/m2 identified inoperable patients with high sensitivity and specificity (95%, AUC 0.99). However, in borderline cases, assessment by this value did not agree with empirical clinical assessment.The median RC time for the entire study population was 0.47 S (IQR 0.30). RC time in operable patients was significantly lower than that in the inoperable patients (Median 0.40 IQR 0.23 in operable, 0.73 0.25 in inoperable patients (p < 0.001).

CONCLUSIONS

Addition of pulmonary arterial compliance to the routine haemodynamic assessment of patients with shunt lesions may improve our understanding of the pulmonary circulation and may have clinical utility.

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.

High haemoglobin levels at the time of occlusion predict worse outcome for patients with patent ductus arteriosus and pulmonary hypertension

INTRODUCTION

Current guidelines discourage shunt closure in patients with pulmonary vascular resistance index >8 Wood units x m2. The study examined the long-term outcome of patients over 15 years old, with pulmonary vascular resistance index >8 Wood units x m2 and patent ductus arteriosus.

MATERIALS AND METHODS

This was a multi-institutional, retrospective study involving all consecutive patients (>15 years old) with patent ductus arteriosus and severe pulmonary hypertension. Patients who had patent ductus arteriosus closure were divided into the Good (no death or hospital admissions due to worsening pulmonary hypertension) and the Poor Outcome groups and these groups were compared.

RESULTS

Thirty-seven patients [male: 9 (24.3%); mean age: 30.49 ± 9.56 years; median follow-up: 3 (IQR: 1.5,10) years] were included from four centers. Twenty-two patients who underwent patent ductus arteriosus closure, 15 (71.4%) had good outcomes while 7 (28.6%) had poor outcomes. Pulmonary vascular resistance index and pulmonary to systemic resistance ratio (Rp:Rs) were lower in the Good Outcome Group (14.35 ± 1.66 Wood units x m2 vs. 20.07 ± 2.44; p = 0.033 and 0.44 ± 0.16 vs. 1.08 ± 1.21; p = 0.042). Haemoglobin concentrations (<14.3 g/dL) were associated with good long-term outcomes in the Closed Group.

CONCLUSIONS

Patients with patent ductus arteriosus with severe pulmonary hypertension have a dismal outcome with or without closure. High haemoglobin levels at the time of occlusion predict a worse outcome for patients with patent ductus arteriosus and pulmonary hypertension.

Pulmonary arterial hypertension in children with congenital heart disease: a deeper look into the role of endothelial progenitor cells and circulating endothelial cells to assess disease severity

Endothelial progenitor cells and circulating endothelial cells have been proposed as useful markers of severity and disease progression in certain vascular diseases, including pulmonary arterial hypertension. Our study focused on evaluating the levels of circulating endothelial progenitor cells and circulating endothelial cells in patients with congenital left-to-right shunts and pulmonary hypertension undergoing definitive repair. Endothelial progenitor cells (identified by simultaneous co-expression of CD45dim, CD34 + and KDR2 + surface antibodies) and circulating endothelial cells (identified by simultaneous co-expression of inherent antibodies CD45-, CD31+, CD146 + and CD105+) were prospectively measured in seventy-four children (including children with Down syndrome), median age six years (2.75-10), with clinically significant left-to-right shunts undergoing transcatheter or surgical repair and compared to thirty healthy controls. Endothelial progenitor cells and, particularly, circulating endothelial cells were significantly higher in children with heart disease and pulmonary arterial hypertension when compared to controls. Endothelial progenitor cells showed significant correlation with pulmonary vascular resistance index when measured both systemically (r = 0.259; p = 0.026) and in the superior vena cava (r = 0.302; p = 0.009). Children with Down syndrome showed a stronger correlation between systemic cellularity and pulmonary vascular resistance index (r = 0.829; p = 0.002). Endothelial progenitor cells were reduced along their transit through the lung, whereas circulating endothelial cells did not suffer any modification across the pulmonary circulation. In children with yet to be repaired left-to-right shunts, endothelial progenitor cells and circulating endothelial cell counts are increased compared to healthy subjects.

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.

Long-Term Follow-Up of Pediatric Patients with Severe Postoperative Pulmonary Hypertension After Correction of Congenital Heart Defects

The surgical repair of congenital heart defects in children with preoperative pulmonary hypertension (PH) is to varying degree associated with the occurrence of postoperative PH. The objective of this study was to follow up children with severe postoperative PH (pulmonary arterial/aortic pressure ratio ≥ 1.0) to evaluate if pulmonary arterial pressure spontaneously normalized or needed PH-targeting therapy and to identify potential high-risk diagnoses for bad outcome. Twenty-five children who developed clinically significant severe PH on at least three occasions postoperatively were included in the follow-up (20-24 years). Data from chart reviews, echocardiographic investigations, and questionnaires were obtained. Three children died within the first year after surgery. Three children were lost to follow-up. The remaining 17 children normalized their pulmonary arterial pressure without the use of PH-targeting drugs at any time during the follow-up. Two children had a remaining mild PH with moderate mitral valve insufficiency. All three children with bad outcome had combined cardiac lesions causing post-capillary pulmonary hypertension. Normalization of the pulmonary arterial pressure occurred in almost all children with severe postoperative PH, without any need of supplemental PH-targeting therapies. All children with bad outcome had diagnoses conformable with post-capillary PH making the use of PH-targeting therapies relatively contraindicated. These data emphasize the need to perform randomized, blinded trials on the use of PH-targeting drugs in children with postoperative PH before accepting it as an indication for routine treatment.

Pulmonary Hypertension in Children across Africa: The Silent Threat

Pulmonary hypertension (PH) is a complex puzzle in Africa, especially among children who present with a cocktail of issues including recurrent pulmonary infections, unoperated congenital heart disease, and advanced rheumatic heart disease. Sickle cell anemia and neonatal complications of transiting from fetal circulation also contribute to the burden of pulmonary hypertension. Mortality from pulmonary arterial hypertension (PAH) remains high in Africa (18-21%), claiming sufferers in the first 6 months after diagnosis. Unfortunately, PH remains underreported in sub-Saharan Africa since many centers lack the capacity to diagnose and confirm it by the recommended gold standard, right heart catheterization. The unresolved burden of unoperated congenital heart lesions and rheumatic heart disease, among other preventable causes, stand out as major causes of PH in African children. This paper highlights pediatric PAH as a result of major gaps in care and illustrates the need for its prevention as well as for the promotion of research into the most important drivers, to prevent premature mortality in the continent.

Hybrid approach to postmyocardial infarction ventricular septal defect repair

Postinfarction ventricular septal rupture is a rare and devastating complication of myocardial infarction. Despite attempts at acute surgical and percutaneous defect closure, morbidity and mortality remain high. Herein, we describe a hybrid surgical and catheter-based approach to defect closure in a 63-year-old woman with postinfarction ventricular septal rupture and cardiogenic shock.

Pulmonary Vascular Resistance Measurement Remains Keystone in Congenital Heart Disease Management

Pulmonary vascular resistance (PVR) plays a major role in congenital heart management and critical decision. The impact of pulmonary vascular disease in the early and late morbidity and mortality after cardiac surgery and interventional catheterization in congenital heart defect (CHD) highlights the importance of critical evaluation for PVR. Currently, PVR is evaluated with invasive cardiac catheterization for hemodynamic data collection, processing, and analysis. Despite the limitation of hemodynamic evaluation in the setting of CHD, accurate data analysis, and interpretation have significant impact on clinical outcome and procedure success. This article reviews the basic calculation of PVR in the setting of congenital heart disease with diagrammatic illustration for easy understanding of the hemodynamic.

Macrophage migration inhibitory factor and chemokine RANTES in young pediatric patients with congenital cardiac communications: Relation to hemodynamic parameters and the presence of Down syndrome

Inflammation and immunity are central in the pathobiology of pulmonary vascular disorders. Preliminary headway has been made in understanding the relationships between inflammatory proteins and clinical parameters in pediatric congenital heart disease. In this study, we analyzed serum levels of macrophage migration inhibitory factor (MIF) and regulated on activation normal T cell expressed and secreted chemokine (RANTES) in 87 patients with unrestrictive congenital cardiac communications and signs of pulmonary hypertension (age 2-36 months) and 50 pediatric controls. They were investigated in relation to clinical and hemodynamic parameters and the presence of Down syndrome. Hemodynamics was assessed by transthoracic Doppler echocardiography and cardiac catheterization. Chemokines were analyzed in serum using a chemiluminescence assay. The highest MIF levels were observed in very young subjects with heightened pulmonary vascular resistance but who presented a positive response to vasodilator challenge with inhaled nitric oxide. In contrast, RANTES levels were higher in patients with pulmonary overcirculation and congestion, correlating nonlinearly with pulmonary blood flow. Levels of both chemokines were higher in subjects with Down syndrome than in nonsyndromic individuals, but the difference was observed only in patients, not in the control group. In patients with Down syndrome, there was a direct relationship between preoperative serum MIF and the level of pulmonary artery pressure observed 6 months after surgical repair of cardiac anomalies. Thus, it was interesting to observe that MIF, which is key in the innate immune response and chemokine RANTES, which is highly expressed in respiratory viral infections were related to clinical and hemodynamic abnormalities associated with pediatric congenital heart disease.

Pulmonary vascular disease in Africa: Lessons from registries

The epidemiology of pulmonary vascular disease (PVD) remains unclear in Africa, where health systems do not reach the majority of the population and heath information systems are poorly developed. In this context, registries are particularly important in gathering crucial information on PVD, aiming at improving knowledge of the epidemiology and/or quality of care. While population-based registries are the main tool to identify incident cases, and be a better indicator of pulmonary vascular disease burden, hospital-based registries can give an indication of the demand for specific care services, which is useful for health policy and planning. The only registry for pulmonary hypertension in Africa - the Pan African Pulmonary Hypertension Cohort (PAPUCO) - involved four countries, and was a pragmatic study that revealed a unique pattern of environmental risks, issues related to low access to health care, and ill-equipped health facilities for diagnosis and management of pulmonary hypertension. In addition, disease specific registries for conditions such as congenital heart disease and rheumatic heart disease uncovered high occurrence of PVD that can be managed and/or prevented with improvements in community awareness, surveillance, management and prevention. It is suggested that existing networks of experts and researchers develop regional registries to determine the epidemiology of PVD in Africa, assess geographic, environmental and seasonal differentials, as well as inform policy and care provision in the continent.

High-risk pregnancy in a patient with pulmonary arterial hypertension due to congenital heart disease (PAH-CHD) with temporary shunt inversion and deoxygenation

Atrial septal defect (ASD) is one of the most frequent congenital heart diseases (CHD). Up to 10% of adults with an ASD develop pulmonary arterial hypertension (PAH, PAH-CHD) in their lifetime. Despite improved therapy options, gravidity remains a substantial risk for both maternal and neonatal mortality in PAH-CHD patients.

In our patient, gravidity remained uncomplicated until week 32, under specific monotherapy with tadalafil, before onset of dyspnea and markedly increase of systolic pulmonary arterial pressure (PAP) was observed in echocardiography. Urgent Caesarian delivery was performed without any complications and a healthy baby was born. However, immediately afterwards, the patient desaturated (SpO2 65%, PaO₂ 37 mmHg) due to a shunt inversion with now right-to-left shunt through the residual ASD. She was admitted to our intensive care unit and specific PH therapy was escalated to a triple combination of tadalafil, ambrisentan, and iloprost. Hereafter, in a slow process of approximately three weeks, the patient's condition improved to baseline.

This rare case of a young woman with high-risk pregnancy in PAH-CHD highlights the hemodynamic changes and treatment options during pregnancy in these patients and emphasizes the urgency of a close monitoring at specialized GUCH/PAH centers with experience in managing PAH under these circumstances.

Challenges in the Patient With Pulmonary Hypertension and Atrial Septal Defect: Understanding When and How to Close the Defect

Atrial septal defects (ASDs) are common congenital heart defects in children and adults. Pulmonary arterial hypertension (PAH) is found in subsets of both pediatric and adult patients with atrial defects under varied clinical contexts. The pulmonary hypertension specialist is often faced with questions surrounding timing and method of defect closure, which may have significant impact on procedural and long-term morbidity and survival. This review highlights important differences in management between children and adults with ASDs associated with PAH, highlighting indications for closure, operability, types of closure, and long-term outcomes.

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.

Assessment of reversibility in pulmonary arterial hypertension and congenital heart disease

Pulmonary arterial hypertension (PAH) in congenital heart disease (CHD) can be reversed by early shunt closure, but this potential is lost beyond a certain point of no return. Therefore, it is crucial to accurately assess the reversibility of this progressive pulmonary arteriopathy in an early stage. Reversibility assessment is currently based on a combination of clinical symptoms and haemodynamic variables such as pulmonary vascular resistance. These measures, however, are of limited predictive value and leave many patients in the grey zone. This review provides a concise overview of the mechanisms involved in flow-dependent progression of PAH in CHD and evaluates existing and future alternatives to more directly investigate the stage of the pulmonary arteriopathy. Structural quantification of the pulmonary arterial tree using fractal branching algorithms, functional imaging with intravascular ultrasound, nuclear imaging, putative new blood biomarkers, genetic testing and the potential for transcriptomic analysis of circulating endothelial cells and educated platelets are being reviewed.

Surgical management of iatrogenic occluded left pulmonary artery

A 4-year-old boy developed dyspnea 18 months after attempted surgical patent ductus arteriosus closure using a clip that was inadvertently placed on the left pulmonary artery, followed by reoperation to repair the left pulmonary artery with a patch and re-close the ductus. Computed tomography angiography confirmed a large patent ductus arteriosus, left pulmonary artery occlusion, and patent left pulmonary veins. Therefore, a third surgery was performed for suture closure of the ductus and left pulmonary artery repair with an interposition tube graft. Follow-up by transthoracic echocardiography and computed tomography angiography showed good flow in the left and right pulmonary arteries.

Management of late presentation congenital heart disease

In many parts of the world, mostly low- and middle-income countries, timely diagnosis and repair of congenital heart diseases (CHDs) is not feasible for a variety of reasons. In these regions, economic growth has enabled the development of cardiac units that manage patients with CHD presenting later than would be ideal, often after the window for early stabilisation - transposition of the great arteries, coarctation of the aorta - or for lower-risk surgery in infancy - left-to-right shunts or cyanotic conditions. As a result, patients may have suffered organ dysfunction, manifest signs of pulmonary vascular disease, or the sequelae of profound cyanosis and polycythaemia. Late presentation poses unique clinical and ethical challenges in decision making regarding operability or surgical candidacy, surgical strategy, and perioperative intensive care management.

Pushing the envelope: a treat and repair strategy for patients with advanced pulmonary hypertension associated with congenital heart disease

Pulmonary arterial hypertension (PAH) is a frequent complication of congenital heart disease as a consequence of altered pulmonary hemodynamics with increased pulmonary blood flow and pressure. The development of pulmonary vascular disease (PVD) in this patient population is an important concern in determining operative strategy. Early, definitive surgical repair, when possible, is the best therapy to prevent and treat PVD. However, this is not possible in some patients because they either presented late, after the development of PVD, or they have complex lesions not amenable to one-step surgical correction, including patients with single ventricle physiology, who have a continuing risk of developing PVD. These patients represent an important, high-risk subgroup and many have been considered inoperable. We present a case series of two patients with complex congenital heart disease and advanced PVD who successfully underwent a treat and repair strategy with aggressive PAH therapies before surgical correction. Both patients had normalization of pulmonary vascular resistance prior to surgical correction. Caution is warranted in applying this strategy broadly and long-term follow-up for these patients is crucial. However, this treat and repair strategy may allow for favorable outcomes among some patients who previously had no therapeutic options.

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.

Relation of Cytokine Profile to Clinical and Hemodynamic Features in Young Patients With Congenital Heart Disease and Pulmonary Hypertension

In congenital heart disease, severity of pulmonary hypertension and operability is defined by noninvasive parameters (clinical history, physical examination, and echocardiography) and sometimes, cardiac catheterization. We investigated how circulating levels of inflammatory mediators correlate with such parameters in a young pediatric population (age, 2.0 months to 3.1 years) and the effects of preoperative pulmonary vasodilator therapy with sildenafil. Cytokines were analyzed in serum using chemiluminescence signals. In the whole patient group (n = 47), interleukin 17E, a Th2 immune response mediator increased with increasing age, considered as a parameter of disease severity (R² = 0.24, p <0.001), whereas the angiogenic chemokine growth-regulated oncogene alpha decreased (R² = 0.21, p = 0.001). Macrophage migration inhibitory factor chemokine was greater in subjects with elevated pulmonary vascular resistance (n = 16, p = 0.022), whereas regulated on activation, normal T cell expressed and secreted chemokine was greater in subjects with pulmonary congestion due to increased pulmonary blood flow (n = 31, p = 0.037). The observations were the same for the specific subpopulation of patients with Down syndrome (p = 0.009 and p = 0.012 for migration inhibitory factor and regulated on activation, normal T cell expressed and secreted in the respective subgroups). Sildenafil administration to patients with elevated pulmonary vascular resistance resulted in improvement of pulmonary blood flow (p = 0.012) and systemic oxygen saturation (p = 0.010), with a decrease in serum interleukin 6 (p = 0.027) and soluble ICAM-1 (p = 0.011). In conclusion, levels of circulating inflammatory molecules seem to correlate with disease severity in this population, with potential pathophysiological and therapeutic implications.

Clinical classification in pediatric pulmonary arterial hypertension associated with congenital heart disease

Congenital heart disease (CHD) is a frequent cause of pediatric pulmonary arterial hypertension (PAH), with diverse etiology and outcome. We aimed to describe phenotypic heterogeneity in pediatric PAH associated with CHD (PAH-CHD), assess the applicability of the Nice CHD classification, and explore whether this classification accurately reflects patient/disease characteristics and survival. All children with CHD from a contemporary cohort of consecutive pediatric PAH patients followed in three major referral centers (Denver, New York, the Netherlands) were characterized and classified on the basis of the latest proposed clinical classification for PAH-CHD (World Symposium on Pulmonary Hypertension, Nice, 2013). According to this classification, 24% of 134 children were classified into group 1, 14% into group 2, 19% into group 3, and 30% into group 4; 11% could not be classified. Types of CHD and hemodynamic profile differed between groups, with the highest right atrial pressure in group 4 (P < 0.040). Group 3 children had Down syndrome less frequently (P = 0.011) but other (un)defined syndromes most frequently (P = 0.063) and received most intense PAH-targeted therapy (P = 0.003). With 15 deaths and one lung transplant (12%; median follow-up: 4.3 years), survival differences could not be demonstrated between the groups in the Nice CHD classification. Pediatric PAH-CHD is a heterogeneous condition frequently associated with extracardiac, developmental factors that are believed to affect disease development. The Nice CHD classification identifies groups with specific patient/disease characteristics. However, a substantial proportion of children could not be classified. Group 3 forms a distinct disease entity. Its prognostic value could not be determined because of the low number of events. The Nice CHD classification supports clinical characterization of PAH-CHD; however, further refinement is needed to classify all children with PAH-CHD.

Serum Cytokines in Young Pediatric Patients with Congenital Cardiac Shunts and Altered Pulmonary Hemodynamics

Background and Objective. Inflammation is central in the pathogenesis of pulmonary hypertension. We investigated how serum cytokines correlate with clinical features, hemodynamics, and lung histology in young patients with pulmonary hypertension associated with congenital cardiac shunts. Design. Prospective, observational study. Methods and Results. Patients (n = 44) were aged 2.6 to 37.6 months. Group I patients (n = 31) were characterized by pulmonary congestion and higher pulmonary blood flow compared to group II (p = 0.022), with no need for preoperative cardiac catheterization. Group II patients (n = 13) had no congestive features. At catheterization, they had elevated pulmonary vascular resistance (5.7 [4.4–7.4] Wood units·m², geometric mean with 95% CI). Cytokines were measured by chemiluminescence. Macrophage migration inhibitory factor (MIF) was found to be inversely related to pulmonary blood flow (r = −0.33, p = 0.026) and was higher in group II (high pulmonary vascular resistance) compared to group I (high pulmonary blood flow) (p = 0.017). In contrast, RANTES chemokine (regulated on activation, normal T cell expressed and secreted) was characteristically elevated in Group I (p = 0.022). Interleukin 16 was also negatively related to pulmonary blood flow (r_S = −0.33, p = 0.029) and was higher in patients with obstructive vasculopathy at intraoperative lung biopsy (p = 0.021). Conclusion. Cytokines seem to be important and differentially regulated in subpopulations of young patients with cardiac shunts.

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.

Cardiac catheterization in children with pulmonary hypertensive vascular disease: consensus statement from the Pulmonary Vascular Research Institute, Pediatric and Congenital Heart Disease Task Forces

Cardiac catheterization is important in the diagnosis and risk stratification of pulmonary hypertensive vascular disease (PHVD) in children. Acute vasoreactivity testing provides key information about management, prognosis, therapeutic strategies, and efficacy. Data obtained at cardiac catheterization continue to play an important role in determining the surgical options for children with congenital heart disease and clinical evidence of increased pulmonary vascular resistance. The Pediatric and Congenital Heart Disease Task Forces of the Pulmonary Vascular Research Institute met to develop a consensus statement regarding indications for, conduct of, acute vasoreactivity testing with, and pitfalls and risks of cardiac catheterization in children with PHVD. This document contains the essentials of those discussions to provide a rationale for the hemodynamic assessment by cardiac catheterization of children with PHVD.

Pulmonary Hypertension in Children - a Practical Approach

Pulmonary hypertension (PH) is mean pulmonary arterial pressure above 25 mmHg at rest. Although considered a rare disease, the prevalence of PH in certain risk groups is higher, from 0.5% in patients with HIV infection to 30% in congenital heart disease (CHD) associating PH. In pulmonary arterial hypertension (PAH) associated with CHD, early changes of the vascular bed are reversible after correction of the defect, but there is a point from where the disease becomes irreversible or progression continues despite correction. Among patients with "operable" and "inoperable" CHD, there is a "gray area" group in between, which is defined by pulmonary vascular resistance equal to 4-8 WU/m and ratio of pulmonary vascular resistance to systemic vascular resistance of 0.3-0.5, measured by cardiac catheterization. In this situation a pulmonary vasoreactivity test is indicated. Pulmonary hypertension is a severe disease with increased morbidity and mortality. Pulmonary hypertension can result in death by decreased cardiac output, and heart failure.

A global perspective on the epidemiology of pulmonary hypertension

The epidemiology of pulmonary hypertension (PH) is not fully determined worldwide but is believed to vary in different regions of the world, with differences determined by genetic, geographic, environmental, and socioeconomic factors, as well as sex-related practices and inequities in access to health care. This article reviews the global epidemiology of PH, with emphasis on the prevalence, causes, forms, and underlying factors in the developing world. Left ventricular heart disease is the most common cause worldwide, but the main contributors in developing countries are chronic infectious diseases, hypertensive heart disease, cardiomyopathy, and rheumatic heart disease. Despite data suggesting a high prevalence in Sub-Saharan Africa, the available literature is very limited. International registries like the Pan African Pulmonary Hypertension Cohort are essential to provide information about the causes, comorbidities, and diagnostic classification, therapeutic management, and the natural course of PH worldwide. Moreover, there is a need to track diagnostic and management practices and challenges to identify the gaps and gradients between different regions of the world. The information gained will pinpoint areas for improvement, aiming at bridging the current divide between low-income and high-income countries.