Pulmonary vascular phenotype identified in patients with GDF2 (BMP9) or BMP10 variants: an international multicentre study.

BACKGROUND: Bone morphogenetic proteins 9 and 10 (BMP9 and BMP10), encoded by GDF2 and BMP10, respectively, play a pivotal role in pulmonary vascular regulation. GDF2 variants have been reported in pulmonary arterial hypertension (PAH) and hereditary haemorrhagic telangiectasia (HHT). However, the phenotype of GDF2 and BMP10 carriers remains largely unexplored. METHODS: We report the characteristics and outcomes of PAH patients in GDF2 and BMP10 carriers from the French and Dutch pulmonary hypertension registries. A literature review explored the phenotypic spectrum of these patients. RESULTS: 26 PAH patients were identified: 20 harbouring heterozygous GDF2 variants, one homozygous GDF2 variant, four heterozygous BMP10 variants, and one with both GDF2 and BMP10 variants. The prevalence of GDF2 and BMP10 variants was 1.3% and 0.4%, respectively. Median age at PAH diagnosis was 30 years, with a female/male ratio of 1.9. Congenital heart disease (CHD) was present in 15.4% of the patients. At diagnosis, most of the patients (61.5%) were in New York Heart Association Functional Class III or IV with severe haemodynamic compromise (median (range) pulmonary vascular resistance 9.0 (3.3-40.6) WU). Haemoptysis was reported in four patients; none met the HHT criteria. Two patients carrying BMP10 variants underwent lung transplantation, revealing typical PAH histopathology. The literature analysis showed that 7.6% of GDF2 carriers developed isolated HHT, and identified cardiomyopathy and developmental disorders in BMP10 carriers. CONCLUSIONS: GDF2 and BMP10 pathogenic variants are rare among PAH patients, and occasionally associated with CHD. HHT cases among GDF2 carriers are limited according to the literature. BMP10 full phenotypic ramifications warrant further investigation.

Safety and preliminary efficacy on cognitive performance and adaptive functionality of epigallocatechin gallate (EGCG) in children with Down syndrome. A randomized phase Ib clinical trial (PERSEUS study).

PURPOSE: Although some caregivers are using epigallocatechin gallate (EGCG) off label in hopes of improving cognition in young adults with Down syndrome (DS), nothing is known about its safety, tolerability, and efficacy in the DS pediatric population. We aimed to evaluate safety and tolerability of a dietary supplement containing EGCG and if EGCG improves cognitive and functional performance. METHODS: A total of 73 children with DS (aged 6-12 years) were randomized. Participants received 0.5% EGCG (10 mg/kg daily dose) or placebo for 6 months with 3 months follow up after treatment discontinuation. RESULTS: In total, 72 children were treated and 66 completed the study. A total of 38 participants were included in the EGCG group and 35 in the placebo group. Of 72 treated participants, 62 (86%) had 229 treatment-emergent adverse events (AEs). Of 37 participants in the EGCG group, 13 (35%) had 18 drug-related treatment-emergent AEs and 12 of 35 (34%) from the placebo group had 22 events. In the EGCG group, neither severe AEs nor increase in the incidence of AEs related to safety biomarkers were observed. Cognition and functionality were not improved compared with placebo. Secondary efficacy outcomes in girls point to a need for future work. CONCLUSION: The use of EGCG is safe and well-tolerated in children with DS, but efficacy results do not support its use in this population.

Upfront triple combination therapy in severe paediatric pulmonary arterial hypertension.

Treatment strategies in paediatric pulmonary arterial hypertension (PAH) have evolved over the last years, but survival is still poor. Recently, in adults with severe PAH, upfront triple combination therapy (uTCT) from diagnosis has been reported to show significant clinical improvement and excellent long-term outcome. This retrospective, observational study aimed to assess the efficacy of uTCT in paediatric PAH.Children diagnosed with PAH between 2010 and 2019 and started with uTCT were included. World Health Organization Functional Class (WHO-FC), haemodynamics, echocardiography, 6-min walking distance and serum level of N-terminal pro-brain-natriuretic-peptide were assessed at baseline, after 3 and 6 months and at last available follow-up. Events were defined as death, lung transplantation or Potts shunt.21 children (median age 4.8 years (2.5-12.8), 57% females) were included. All children except one were in WHO-FC III or IV (28% and 67%, respectively). After 3 months, one child had died and one child had received a Potts shunt. The remaining 19 children showed clinical and echocardiographic improvement, which persisted at 6 months. Children with idiopathic and heritable PAH showed one-, two- and three-year transplant-free survival estimates of 100%, 94% and 87%, albeit 47% of them receiving a Potts shunt during follow-up.Children with severe PAH, but not pulmonary veno-occlusive disease, improved significantly with uTCT and showed beneficial up to 3-year survival rates, albeit 47% of them receiving a Potts shunt during follow-up. The role of a Potts shunt in conjunction to uTCT in paediatric PAH needs to be further established.

Pulmonary hypertension associated with congenital heart block and neonatal lupus syndrome: A series of four cases.

OBJECTIVE: Neonatal lupus syndrome has multisystemic manifestations among which pulmonary involvement has been rarely reported. We describe the clinical presentation, management, and outcome of a series of four neonates who developed reversible pulmonary hypertension associated with auto-immune congenital complete heart block. METHOD: Data from the French registry of neonatal lupus syndrome were retrospectively reviewed. RESULTS: Between 2000 and March 2020, 231 children were included in the French registry, four/73 followed in our institution developed pulmonary hypertension. Diagnosis was suspected on transthoracic echocardiography at a median age of 42 days [range 10-58], and confirmed by right heart catheterization in all; 2 of them where paced at time of diagnosis and 2 were not. All had some degree of hypoxemia and respiratory distress. Hypoxemia was always reversible under O2 et NO. Lung CT demonstrated ground glass anomalies in all. One patient had a lung biopsy consistent with pulmonary hypertension secondary to lung disease. Management included immunosuppressive therapy in 3 associated with sildenafil in 2. Pulmonary hypertension resolved in all at a median age of 4 weeks [range 3-6] after treatment initiation and after one year for the one child who did not receive specific treatment. CONCLUSION: Clinical, hemodynamical, imaging and histological findings advocate for pulmonary hypertension associated with respiratory disease as a rare manifestation of neonatal lupus syndrome.

Phenotype and outcome of pulmonary arterial hypertension patients carrying a TBX4 mutation.

INTRODUCTION: TBX4 mutation causes small patella syndrome (SPS) and/or pulmonary arterial hypertension (PAH). The characteristics and outcomes of PAH associated with TBX4 mutations are largely unknown. METHODS: We report the clinical, functional, radiologic, histologic and haemodynamic characteristics and outcomes of heritable PAH patients carrying a TBX4 mutation from the French pulmonary hypertension (PH) network. RESULTS: 20 patients were identified in 17 families. They were characterised by a median age at diagnosis of 29 years (0-76 years) and a female to male ratio of three. Most of the patients (70%) were in New York Heart Association (NYHA) functional class III or IV with a severe haemodynamic impairment (median pulmonary vascular resistance (PVR) of 13.6 (6.2-41.8) Wood units). Skeletal signs of SPS were present in 80% of cases. Half of the patients had mild restrictive or obstructive limitation and diffusing capacity of the lung for carbon monoxide (D LCO) was decreased in all patients. High-resolution computed tomography (HRCT) showed bronchial abnormalities, peri-bronchial cysts, mosaic distribution and mediastinal lymphadenopathies. PAH therapy was associated with significant clinical improvement. At follow-up (median 76 months), two patients had died and two had undergone lung transplantation. One-year, three-year and five-year event-free survival rates were 100%, 94% and 83%, respectively. Histologic examination of explanted lungs revealed alveolar growth abnormalities, major pulmonary vascular remodelling similar to that observed in idiopathic pulmonary arterial hypertension (IPAH) and accumulation of cholesterol crystals within the lung parenchyma. CONCLUSION: PAH due to TBX4 mutations may occur with or without skeletal abnormalities across a broad age range from birth to late adulthood. PAH is usually severe and associated with bronchial and parenchymal abnormalities.

Pulmonary hypertension after bone marrow transplantation in children.

INTRODUCTION: Pulmonary hypertension is a rare but important cause of mortality after haematopoietic stem cell transplantation (HSCT) in children. This complication is poorly characterised in the literature. We report here a series of children who developed pulmonary hypertension after HSCT. METHODS: Between January 2008 and December 2015, we retrospectively analysed 366 children who underwent HSCT (age range 0.5-252 months; median 20.3 months). During the post-HSCT course, echocardiography scans motivated by respiratory symptoms identified 31 patients with elevated tricuspid regurgitation velocity (>2.8 m·s-1), confirmed when possible by right heart catheterisation (RHC). RESULTS: 22 patients had confirmed pulmonary hypertension with mean±sd pulmonary arterial pressure 40.1±10 mmHg (range 28-62 mmHg) and pulmonary vascular resistance 17.3±9.2 Wood Units (range 8-42 Wood Units). Among the 13 responders at reactivity test, only one patient responded to calcium channel blockers. Seven patients (32%) died. 15 pulmonary hypertension patients were alive after a mean±sd follow-up of 6.5±2.3 years (range 2-10 years). All survivors could be weaned off pulmonary hypertension treatment after a median follow-up of 5 months (range 3-16). The delay between clinical symptoms and initiation of pulmonary hypertension therapy was significantly longer in patients who subsequently died (mean±sd 33.5±23 days; median 30 days) than in survivors (mean±sd 7±3 days) (p<0.001). CONCLUSION: Pulmonary hypertension is a severe complication of HSCT with an underestimated incidence and high mortality. Aggressive and timely up-front combination therapy allowed normalisation of pulmonary pressure and improved survival.

Widening the landscape of heritable pulmonary hypertension mutations in paediatric and adult cases.

BACKGROUND: Heritable forms of pulmonary arterial hypertension (PAH) and pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis (PVOD/PCH) diverge by lung histopathological lesions, clinical and para-clinical presentation, their responsible genes, and mode of transmission. Since the identification of the BMPR2 gene in families affected by PAH, mutations in several other genes have been discovered for both forms. The mutation landscape in these new genes is not yet well known. METHODS: We set up a next-generation sequencing-based targeted sequencing gene panel allowing known genes for PAH and PVOD/PCH to be analysed simultaneously. Genetic analysis was prospectively performed on 263 PAH and PVOD/PCH patients (adult and paediatric cases). RESULTS: Pathogenic mutations were identified in 19.5% of sporadic PAH patients (n=180), 54.5% of familial PAH patients and 13.3% of PVOD/PCH patients. BMPR2 was the most frequently mutated gene, followed by TBX4 in both paediatric and adult PAH. BMP9 mutations were identified in 1.2% of adult PAH cases. EIF2AK4 biallelic mutations were restricted to PVOD/PCH. A truncating mutation and a predicted loss-of-function variant were also identified in BMP10 in two severely affected sporadic PAH female patients. CONCLUSION: Our results confirm that mutations are found in genes beyond BMPR2 in heritable PAH, emphasise the role of TBX4 and BMP9, and designate BMP10 as a new PAH gene.

Idiopathic, heritable and veno-occlusive pulmonary arterial hypertension in childhood: computed tomography angiography features in the initial assessment of the disease.

BACKGROUND: In children, idiopathic and heritable pulmonary arterial hypertension present echocardiographic and heart catheterization findings similar to findings in pulmonary veno-occlusive disease. OBJECTIVE: To provide a systematic analysis of CT angiography anomalies in children with idiopathic or heritable pulmonary arterial hypertension, or pulmonary veno-occlusive disease. We also sought to identify correlations between CT findings and patients' baseline characteristics. MATERIALS AND METHODS: We retrospectively analyzed CT features of children with idiopathic and heritable pulmonary arterial hypertension or pulmonary veno-occlusive disease and 30 age-matched controls between 2008 and 2014. We compared CT findings and patient characteristics, including gene mutation type, and disease outcome until 2017. RESULTS: The pulmonary arterial hypertension group included idiopathic (n=15) and heritable pulmonary arterial hypertension (n=11) and pulmonary veno-occlusive disease (n=4). Median age was 6.5 years. Children with pulmonary arterial hypertension showed enlargement of pulmonary artery and right cardiac chambers. A threshold for the ratio between the pulmonary artery and the ascending aorta of ≥1.2 had a sensitivity of 90% and a specificity of 100% for pulmonary arterial hypertension. All children with pulmonary veno-occlusive disease had thickened interlobular septa, centrilobular ground-glass opacities, and lymphadenopathy. In children with idiopathic and heritable pulmonary arterial hypertension, presence of intrapulmonary neovessels and enlargement of the right atrium were correlated with higher mean pulmonary artery pressure (P=0.011) and pulmonary vascular resistance (P=0.038), respectively. Mediastinal lymphadenopathy was associated with disease worsening within the first 2 years of follow-up (P=0.024). CONCLUSION: CT angiography could contribute to early diagnosis and prediction of severity in children with pulmonary arterial hypertension.

Neonatal management and outcomes of prenatally diagnosed CHDs.

OBJECTIVES: The aim of this study was to determine the probability of intervention at birth after prenatal diagnosis of CHD. METHODS: A 10-year retrospective study including all foetuses with a prenatally diagnosed CHD and those delivered in a tertiary-care cardiac centre between January, 2002 and December, 2011 was carried out. Patients were classified into eight groups according to the anticipated risk of neonatal intervention. RESULTS: The need for urgent intervention and/or PGE1 infusion within the first 48 hours of life was 47% (n=507/1080): 72% (n=248) for CHD at risk for a Rashkind procedure, 77% (n=72) for CHD with ductal-dependent pulmonary flow, 13% (n=22) for CHD with potentially ductal-dependent pulmonary flow, 94% (n=62) for CHD with ductal-dependent systemic flow, 29% (n=88) for CHD with potentially ductal-dependant systemic flow, 50% (n=4) for total anomalous pulmonary venous connection, and 17% (n=1) for CHD with atrio-ventricular block. In all, 34% of the patients received PGE1 infusion and 21.4% underwent urgent catheter-based or surgical interventions; 10% of patients without anticipated risk (n=10) underwent an early intervention; 6.7% (n=73) of the patients died; and 55% (n=589) had an intervention before discharge from hospital. CONCLUSION: Half of the neonates with foetal CHD benefited from an urgent intervention or PGE1 infusion at birth. We recommend scheduled delivery and in utero transfer for transposition of the great arteries, double-outlet right ventricle with sub-pulmonary ventricular septal defect, total anomalous pulmonary venous connection, CHD with atrio-ventricular block with heart rate <50, all ductal-dependant lesions, and CHD with potentially ductal-dependant systemic flow.

Genetic analyses in a cohort of children with pulmonary hypertension.

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

Pulmonary Hypertension Induced by Right Pulmonary Artery Occlusion: Hemodynamic Consequences of Bmpr2 Mutation.

BACKGROUND: The primary genetic risk factor for heritable pulmonary arterial hypertension is the presence of monoallelic mutations in the BMPR2 gene. The incomplete penetrance of BMPR2 mutations implies that additional triggers are necessary for pulmonary arterial hypertension occurrence. Pulmonary artery stenosis directly raises pulmonary artery pressure, and the redirection of blood flow to unobstructed arteries leads to endothelial dysfunction and vascular remodeling. We hypothesized that right pulmonary artery occlusion (RPAO) triggers pulmonary hypertension (PH) in rats with Bmpr2 mutations. METHODS AND RESULTS: Male and female rats with a 71 bp monoallelic deletion in exon 1 of Bmpr2 and their wild-type siblings underwent acute and chronic RPAO. They were subjected to full high-fidelity hemodynamic characterization. We also examined how chronic RPAO can mimic the pulmonary gene expression pattern associated with installed PH in unobstructed territories. RPAO induced precapillary PH in male and female rats, both acutely and chronically. Bmpr2 mutant and male rats manifested more severe PH compared with their counterparts. Although wild-type rats adapted to RPAO, Bmpr2 mutant rats experienced heightened mortality. RPAO induced a decline in cardiac contractility index, particularly pronounced in male Bmpr2 rats. Chronic RPAO resulted in elevated pulmonary IL-6 (interleukin-6) expression and decreased Gdf2 expression (corrected P value<0.05 and log2 fold change>1). In this context, male rats expressed higher pulmonary levels of endothelin-1 and IL-6 than females. CONCLUSIONS: Our novel 2-hit rat model presents a promising avenue to explore the adaptation of the right ventricle and pulmonary vasculature to PH, shedding light on pertinent sex- and gene-related effects.

Respiratory outcome in children with scimitar syndrome.

OBJECTIVE: To evaluate respiratory morbidities and lung function tests in the cohort of patients with scimitar syndrome evaluated at our center since 1976. STUDY DESIGN: Eighty-one children were investigated. Twenty-six patients died, all with the infantile form. The median duration of follow-up of surviving children was 7.2 years. RESULTS: A high rate of respiratory morbidities was measured, with 38% and 43% of children reporting pulmonary infections or wheezing episodes during the last 12 months of follow-up, respectively. One-third of children have been rehospitalized for a respiratory cause. Lung function tests were obtained in 20 children. The median value of total lung capacity was 73.0% of the predicted value (IQR, 65.3-86.8), and the median value of the ratio of the forced expiratory volume in one second to the forced vital capacity was -1.26 Z score (-2.25; -0.31). Significantly lower total lung capacity values were obtained in children with the infantile form (P < .005) or with a history of thoracic surgery (P = .002). The ratio of the forced expiratory volume in one second to the forced vital capacity Z score values were significantly lower in boys (P < .05) and in children with a history of wheezing (P = .01). Wheezing episodes were not associated with significant salbutamol-induced reversibility. CONCLUSION: Respiratory complications frequently are observed in children with scimitar syndrome. Pulmonary hypoplasia appears as an independent marker of long-term severity in these patients.

Monitoring of Hemodynamics With Right Heart Catheterization in Children With Pulmonary Arterial Hypertension.

Background Right heart catheterization (RHC) is a high-risk procedure in children with pulmonary arterial hypertension without clear guidelines for the indications and targets of invasive reassessment. Our objectives are to define the aims of repeated RHC and evaluate the correlation between noninvasive criteria and hemodynamic parameters. Methods and Results Clinical and hemodynamic characteristics from 71 incident treatment-naïve children (median age 6.2 years) with pulmonary arterial hypertension who had a baseline and reevaluation RHC were analyzed. Correlations between noninvasive predictors and hemodynamic parameters were tested. Adverse outcomes were defined as death, lung transplantation, or Potts shunt. At baseline, pulmonary vascular resistance index (hazard ratio [HR] 1.07 per 1 WU·m2 increase [95% CI, 1.02-1.12], P=0.002), stroke volume index (HR 0.95 per 1 L·min-1·m-2 increase [95% CI, 0.91-0.99], P=0.012), pulmonary artery compliance index (HR 0.16 per 1 mL·mm Hg-1·m-2 increase [95% CI, 0.051-0.52], P=0.002), and right atrial pressure (HR, 1.31 per 1 mm Hg increase [95% CI, 1.01-1.71], P=0.043) were associated with adverse outcomes. Pulmonary vascular resistance index, pulmonary artery compliance index, and right atrial pressure were still associated with a worse outcome at second RHC. Noninvasive criteria accurately predicted hemodynamic evolution; however, 70% of the patients who had improved based on noninvasive criteria still presented at least 1 "at risk" hemodynamics at second RHC. Conclusions Pulmonary vascular resistance index, pulmonary artery compliance index, and right atrial pressure are solid predictors of adverse outcomes in pediatric pulmonary arterial hypertension and potential therapeutic targets. Noninvasive criteria accurately predict the evolution of hemodynamic parameters, but insufficiently. Repeated RHC are helpful to identify children with persistent higher risk after treatment introduction.

Tobacco-associated pulmonary vascular dysfunction in smokers: role of the ET-1 pathway.

Pulmonary vascular remodeling and dysfunction associated to tobacco smoking might pave the way for the subsequent development of pulmonary hypertension. Its prognosis is dreadful and its underlying mechanisms are so far largely unknown in humans. To assess the potential role of endothelin-1 and its receptors in smokers' pulmonary artery vasoactive properties. Endothelium-dependent vasodilation to ACh was assessed in pulmonary vascular rings from 34 smokers and compared with that of 10 nonsmokers. The effects of ET-A (BQ 123) or ET-B (BQ 788) blockers and that of an ET-B activator (sarafotoxin) were evaluated. Endothelin-1 was quantitated by ELISA. Expression of its receptors was quantitated by Western blotting. Smokers exhibited an impaired pulmonary endothelium-dependent vasodilation compared with nonsmokers (P < 0.01). In the former group, 8 of 34 subjects exhibited a marked endothelial dysfunction (ED(+)) whereas 26 (ED(-)) (P < 10(-4)) displayed a vasorelaxation to ACh that was comparable to that of nonsmokers. In ED(+) subjects, ET-A was overexpressed (P < 0.05) and inversely correlated (P < 10(-2)) with the response to ACh. Sarafotoxin significantly improved vasodilation in all subjects (P < 10(-2)). In conclusion, tobacco smoking is associated to an impaired pulmonary vasorelaxation at least partly mediated by an ET-1/ET-A-dependent dysfunction.

Treprostinil increases the number and angiogenic potential of endothelial progenitor cells in children with pulmonary hypertension.

BACKGROUND: Pulmonary vasodilators in general and prostacyclin therapy in particular, have markedly improved the outcome of patients with pulmonary arterial hypertension (PAH). As endothelial dysfunction is a key feature of PAH, and as endothelial progenitor cells (EPC) may contribute to vascular repair in PAH, we suspected that prostacyclin therapy might enhance EPC numbers and functions. In the present study, objectives were to determine whether EPC may contribute to vasodilator treatment efficacy in PAH. METHODS: We quantified CD34+ cells, CFU-Hill and ECFC (endothelial colony forming cells) in peripheral blood from children with idiopathic PAH (n = 27) or PAH secondary to congenital heart disease (n = 52). CD34+ were enumerated by flow cytometry, CFU-Hill and ECFC by a culture assay. ECFC grown ex vivo were tested for their angiogenic capacities before and after prostacyclin analog therapy (subcutaneous treprostinil). RESULTS: ECFC counts were significantly enhanced in the 8 children treated with treprostinil, while no change was observed in children receiving oral therapy with endothelin antagonists and/or PDE5 inhibitors. CD34+ cell and CFU-Hill counts were unaffected. ECFC from patients treated with treprostinil had a hyperproliferative phenotype and showed enhanced angiogenic potential in a nude mouse preclinical model of limb ischemia. CONCLUSIONS: ECFC may partly mediate the clinical benefits of prostanoids in pulmonary arterial hypertension.

Add-on therapy with subcutaneous treprostinil for refractory pediatric pulmonary hypertension.

OBJECTIVE: To evaluate the efficacy and tolerability of subcutaneous (SC) treprostinil, a prostacyclin analogue, in young children with refractory pulmonary arterial hypertension. STUDY DESIGN: Eight children (median age, 4 years) received SC treprostinil therapy after failure of combined oral treatment (n = 7) or because of severe complications with intravenous epoprostenol (n = 1). Treprostinil was delivered through an SC catheter at gradually increasing doses to an average of 40 ng/kg/min, depending on the presence of adverse effects. RESULTS: Seven patients demonstrated early significant improvement (in functional class, hemodynamics, and/or 6-minute walk distance; P <.05), and 6 had a sustained good response. Site pain could be effectively managed in all but one child. CONCLUSIONS: Treprostinil may be a potentially valuable rescue therapy in children with refractory pulmonary arterial hypertension, but further study in a larger number of patients is needed.

Potts anastomosis in children with severe pulmonary arterial hypertension and atrial septal defect.

AIMS: Potts shunt has been proposed as a bridge or alternative to lung transplantation for children with severe and drug-refractory suprasystemic pulmonary arterial hypertension (PAH). We describe the management of the atrial shunt when a Potts shunt is planned in refractory PAH. METHODS AND RESULTS: We report a case series of children in whom a Potts shunt was done for severe PAH associated with an atrial septal defect to illustrate the different clinical and haemodynamic scenarios. Five children (2 to 13 years) underwent a Potts shunt: three surgical, one percutaneous Potts shunt, and one percutaneous stenting of a restrictive arterial duct. All had associated atrial septal defect. Those who had generalized cyanosis before the procedure had a complicated postoperative course and required longer ventilatory and inotropic support, except the one who had atrial septal defect closure before the Potts shunt. One of the three cyanotic patients died. Two patients with left-to-right shunt before the Potts shunt had an uncomplicated postoperative course. CONCLUSIONS: Shunt physiology is only partially predictable after the Potts shunt in children with PAH and atrial septal defect. Abrupt drop in left ventricle preload while the right ventricle is decompressed can potentially be prevented by atrial septal defect closure prior to the Potts shunt.

Lung and heart-lung transplantation for children with PAH: Dramatic benefits from the implementation of a high-priority allocation program in France.

PURPOSE: Pulmonary arterial hypertension (PAH) is rare but remains fatal in infants and children despite the advance of targeted therapies. Lung transplantation (LTx), first performed in pediatric patients in the 1980s, is, with the Potts shunt, the only potentially life-extending option in patients with end-stage PAH but is possible only in tightly selected patients. Size-matching challenges severely restrict the donor organ pool, resulting-together with peculiarities of PAH in infants-in high waitlist mortality. We aimed to investigate survival when using a high-priority allocation program (HPAP) in children with PAH listed for double-LTx or heart-LTx. METHODS: We conducted a single-center, retrospective, before-after study of consecutive children with severe Group 1 PAH listed for double-LTx or heart-LTx between 1988 and 2019. The HPAP was implemented in France in 2006 and 2007 for heart-LTx and double-LTx, respectively. RESULTS: Fifty-five children with PAH were listed for transplantation. Mean age at transplantation was 15.8±2.8 years and 72% had heart-lung transplantation. PAH was usually idiopathic (65%) or due to congenital heart disease (25%). HPAP implementation resulted in the following significant benefits: Decreased cumulative incidence of waitlist death within 1 and 2 years (p < 0.0001); increased cumulative incidence of transplantation within 6 months, from 44% to 67% (p < 0.01); and improved survival after listing (at 1, 3, and 5 years: 61%, 50%, and 44% vs. 92%, 84%, and 72% before and after HPAP implementation, respectively; p = 0.02). CONCLUSION: HPAP implementation was associated with significant improvements in access to transplantation and in survival after listing in children with end-stage PAH.

Pulmonary-to-Systemic Arterial Shunt to Treat Children With Severe Pulmonary Hypertension.

BACKGROUND: The placement of a pulmonary-to-systemic arterial shunt in children with severe pulmonary hypertension (PH) has been demonstrated, in relatively small studies, to be an effective palliation for their disease. OBJECTIVES: The aim of this study was to expand upon these earlier findings using an international registry for children with PH who have undergone a shunt procedure. METHODS: Retrospective data were obtained from 110 children with PH who underwent a shunt procedure collected from 13 institutions in Europe and the United States. RESULTS: Seventeen children died in-hospital postprocedure (15%). Of the 93 children successfully discharged home, 18 subsequently died or underwent lung transplantation (20%); the mean follow-up was 3.1 years (range: 25 days to 17 years). The overall 1- and 5-year freedom from death or transplant rates were 77% and 58%, respectively, and 92% and 68% for those discharged home, respectively. Children discharged home had significantly improved World Health Organization functional class (P < 0.001), 6-minute walk distances (P = 0.047) and lower brain natriuretic peptide levels (P < 0.001). Postprocedure, 59% of children were weaned completely from their prostacyclin infusion (P < 0.001). Preprocedural risk factors for dying in-hospital postprocedure included intensive care unit admission (hazard ratio [HR]: 3.2; P = 0.02), mechanical ventilation (HR: 8.3; P < 0.001) and extracorporeal membrane oxygenation (HR: 10.7; P < 0.001). CONCLUSIONS: A pulmonary-to-systemic arterial shunt can provide a child with severe PH significant clinical improvement that is both durable and potentially free from continuous prostacyclin infusion. Five-year survival is comparable to children undergoing lung transplantation for PH. Children with severely decompensated disease requiring aggressive intensive care are not good candidates for the shunt procedure.

Circulating endothelial cells: a new candidate biomarker of irreversible pulmonary hypertension secondary to congenital heart disease.

BACKGROUND: Congenital heart disease can be complicated by pulmonary arterial hypertension (PAH), the reversibility of which is often difficult to predict. We recently reported a lung biopsy study showing impaired apoptotic regulation of endothelial cells in irreversible PAH. The objective of the present study was to identify noninvasive biomarkers of endothelial turnover that could be used to identify congenital heart disease patients at risk of irreversible PAH. METHODS AND RESULTS: Circulating endothelial cells (CECs) isolated with CD146-coated beads and circulating CD34(+)CD133(+) progenitor cells (CPCs) were quantified in peripheral vein, pulmonary artery, and pulmonary vein blood samples from 26 patients with congenital heart disease (16 with reversible PAH [median age 2 years] and 10 with irreversible PAH [median age 9 years]) and 5 control patients. Surgical lung biopsy was performed in 19 cases. As expected, endothelial remodeling was observed in irreversible PAH but not in reversible PAH. CEC and CPC numbers were each similar in the 3 types of blood samples. CEC numbers were significantly higher in patients with irreversible PAH (median 57 CEC/mL) than in patients with reversible PAH and control subjects (median 3 CEC/mL in the 2 groups). In contrast, CPC numbers did not differ among patients with irreversible or reversible PAH and control subjects (median 84, 64, and 44 CPC/10(5) lymphocytes, respectively, in the 3 groups). CONCLUSIONS: Irreversible PAH in congenital heart disease is associated with endothelial damage and with increased circulating endothelial cell counts. The present study suggests that CECs could be a valuable tool to define therapeutic strategies in congenital heart disease patients with PAH.