Paediatric pulmonary arterial hypertension: updates on definition, classification, diagnostics and management.

Paediatric pulmonary arterial hypertension (PAH) shares common features of adult disease, but is associated with several additional disorders and challenges that require unique approaches. This article discusses recent advances, ongoing challenges and distinct approaches for the care of children with PAH, as presented by the Paediatric Task Force of the 6th World Symposium on Pulmonary Hypertension. We provide updates of the current definition, epidemiology, classification, diagnostics and treatment of paediatric PAH, and identify critical knowledge gaps. Several features of paediatric PAH including the prominence of neonatal PAH, especially in pre-term infants with developmental lung diseases, and novel genetic causes of paediatric PAH are highlighted. The use of cardiac catheterisation as a diagnostic modality and haemodynamic definitions of PAH, including acute vasoreactivity, are addressed. Updates are provided on issues related to utility of the previous classification system to reflect paediatric-specific aetiologies and approaches to medical and interventional management of PAH, including the Potts shunt. Although a lack of clinical trial data for the use of PAH-targeted therapy persists, emerging data are improving the identification of appropriate targets for goal-oriented therapy in children. Such data will likely improve future clinical trial design to enhance outcomes in paediatric PAH

Psychology and aggression

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68264/2/10.1177_002200275900300301.pd

Loss-of-function ABCC8 mutations in pulmonary arterial hypertension

Background: In pulmonary arterial hypertension (PAH), pathological changes in pulmonary arterioles progressively raise pulmonary artery pressure and increase pulmonary vascular resistance, leading to right heart failure and high mortality rates. Recently, the first potassium channelopathy in PAH, because of mutations in KCNK3, was identified as a genetic cause and pharmacological target. Methods: Exome sequencing was performed to identify novel genes in a cohort of 99 pediatric and 134 adult-onset group I PAH patients. Novel rare variants in the gene identified were independently identified in a cohort of 680 adult-onset patients. Variants were expressed in COS cells and function assessed by patch-clamp and rubidium flux analysis. Results: We identified a de novo novel heterozygous predicted deleterious missense variant c.G2873A (p.R958H) in ABCC8 in a child with idiopathic PAH. We then evaluated all individuals in the original and a second cohort for rare or novel variants in ABCC8 and identified 11 additional heterozygous predicted damaging ABCC8 variants. ABCC8 encodes SUR1 (sulfonylurea receptor 1)—a regulatory subunit of the ATP-sensitive potassium channel. We observed loss of ATP-sensitive potassium channel function for all ABCC8 variants evaluated and pharmacological rescue of all channel currents in vitro by the SUR1 activator, diazoxide. Conclusions: Novel and rare missense variants in ABCC8 are associated with PAH. Identified ABCC8 mutations decreased ATP-sensitive potassium channel function, which was pharmacologically recovered

Growth in children with pulmonary arterial hypertension: a longitudinal retrospective multiregistry study.

To enable adequate interpretation of growth measurements in the management of children with pulmonary arterial hypertension (PAH), we assessed growth and its associated determinants in children with PAH. We did a retrospective longitudinal study of height and body-mass index in reference to WHO growth standards by pooling data from four contemporary prospective registries of paediatric PAH representing 53 centres in 19 countries. The main outcome measures were median height for age and body-mass index for age percentiles and longitudinal deviation of height for age and body-mass index for age Z scores from WHO standards. 601 children were followed up for a median of 2·9 years (IQR 1·5-4·4). Baseline median height for age percentile was 26 (IQR 4-54) and baseline median body-mass index for age percentile was 41 (IQR 12-79). Mean height for age Z score was significantly lower than the reference (-0·81, 95% CI -0·93 to -0·69; p<0·0001), as was body-mass index for age Z score (-0·12, -0·25 to -0·01; p=0·047). Height for age Z score was particularly decreased in young patients (aged ≤5 years) with idiopathic or hereditary PAH and in all patients with PAH associated with congenital heart disease. Although Z scores increased in some patients and decreased in others, we detected no significant trend in height for age Z score (p=0·57) or body-mass index for age Z score (p=0·48) before taking account of covariates. Multivariable linear mixed effects modelling showed that age, cause of PAH, ex-prematurity, WHO functional class, trisomy 21, and time since diagnosis were associated with height for age Z score, whereas age, ethnicity, and trisomy 21 were associated with body-mass index for age Z score. A favourable WHO functional class course was independently associated with increases in height for age Z score. PAH is associated with impaired growth, especially in younger children and those with pulmonary arterial hypertension associated with congenital heart disease. The degree of impairment is independently associated with cause of PAH and comorbidities, but also with disease severity and duration. Because a favourable clinical course was associated with catch-up growth, height for age could serve as an additional and globally available clinical parameter to monitor patients' clinical condition. Actelion Pharmaceuticals

Intravascular Ultrasound Pulmonary Artery Denervation to Treat Pulmonary Arterial Hypertension (TROPHY1): Multicenter, Early Feasibility Study

Objectives: The aim of this study was to investigate whether therapeutic intravascular ultrasound pulmonary artery denervation (PDN) is safe and reduces pulmonary vascular resistance (PVR) in patients with pulmonary arterial hypertension (PAH) on a minimum of dual oral therapy. Background: Early studies have suggested that PDN can reduce PVR in patients with PAH. Methods: TROPHY1 (Treatment of Pulmonary Hypertension 1) was a multicenter, international, open-label trial undertaken at 8 specialist centers. Patients 18 to 75 years of age with PAH were eligible if taking dual oral or triple nonparenteral therapy and not responsive to acute vasodilator testing. Eligible patients underwent PDN (TIVUS System). The primary safety endpoint was procedure-related adverse events at 30 days. Secondary endpoints included procedure-related adverse events, disease worsening and death to 12 months, and efficacy endpoints that included change in pulmonary hemodynamic status, 6-min walk distance, and quality of life from baseline to 4 or 6 months. Patients were to remain on disease-specific medication for the duration of the study. Results: Twenty-three patients underwent PDN, with no procedure-related serious adverse events reported. The reduction in PVR at 4- or 6-month follow-up was 94 ± 151 dyn·s·cm−5 (p = 0.001) or 17.8%, which was associated with a 42 ± 63 m (p = 0.02) increase in 6-min walk distance and a 671 ± 1,555 step (p = 0.04) increase in daily activity. Conclusions: In this multicenter early feasibility study, PDN with an intravascular ultrasound catheter was performed without procedure-related adverse events and was associated with a reduction in PVR and increases in 6-min walk distance and daily activity in patients with PAH on background dual or triple therapy.SCOPUS: ar.jinfo:eu-repo/semantics/publishe