Still puzzling about a clear definition of pulmonary arterial hypertension in newborns

Metabolomics in Pulmonary Hypertension-A Useful Tool to Provide Insights into the Dark Side of a Tricky Pathology

Pulmonary hypertension (PH) is a multifaceted illness causing clinical manifestations like dyspnea, fatigue, and cyanosis. If left untreated, it often evolves into irreversible pulmonary arterial hypertension (PAH), leading to death. Metabolomics is a laboratory technique capable of providing insights into the metabolic pathways that are responsible for a number of physiologic or pathologic events through the analysis of a biological fluid (such as blood, urine, and sputum) using proton nuclear magnetic resonance spectroscopy or mass spectrometry. A systematic review was finalized according to the PRISMA scheme, with the goal of providing an overview of the research papers released up to now on the application of metabolomics to PH/PAH. So, eighty-five papers were identified, of which twenty-four concerning PH, and sixty-one regarding PAH. We found that, from a metabolic standpoint, the hallmarks of the disease onset and progression are an increase in glycolysis and impaired mitochondrial respiration. Oxidation is exacerbated as well. Specific metabolic fingerprints allow the characterization of some of the specific PH and PAH subtypes. Overall, metabolomics provides insights into the biological processes happening in the body of a subject suffering from PH/PAH. The disarranged metabolic pathways underpinning the disease may be the target of new therapeutic agents. Metabolomics will allow investigators to make a step forward towards personalized medicine.

Idiopathic Pulmonary Arterial Hypertension in Paediatrics Represents Still a Serious Challenge: A Case Series Study

Introduction: Paediatric pulmonary hypertension (PH) represents a heterogeneous illness that is responsible for high morbidity and mortality if left without treatment. Idiopathic pulmonary arterial hypertension (IPAH) is a subtype of PAH rarely seen in paediatrics. Limited long-term data are available. Methods: Over a period of 20 years, 10 paediatric patients were enrolled at two tertiary centres. Their clinical, echocardiographic, and right heart catheterisation (RHC) features and outcome were evaluated. Results: The mean age at first diagnosis was 5.7 ± 5.7 years. The age at the last follow-up was 12.4 ± 6.1 years. The average follow-up was 6.6 ± 0.8 years. There was a female prevalence of 60% (p < 0.05) in this case series. Regarding the NYHA functional class, 80% of IPAH subjects were in class III or IV. The mean saturation was 91 ± 5%. In this regard, 70% of the patients were on a combination of three drugs, with sildenafil (90%) included. On echocardiography, longitudinal right ventricular contractility (TAPSE) was slightly reduced (13.4 ± 2.6 mm), whilst RVSP was severely elevated (101 ± 19 mmHg). The RHC data showed that mPAP was 61.8 ± 23.1 mmHg (p = 0.0017 with RVSP on echocardiography), mRAP was 10.7 ± 3.8 mmHg, CI was 2.6 ± 1 L·min−1·m−2, PVRi was 16.8 ± 12.6 WU·m2, and SVO2 was 63.6 ± 14.8%. Regarding the outcome, two male IPAH patients (20%) died, and 50% underwent lung transplant or were on transplant assessment or already on the waiting list for lung transplantation. One patient underwent a ductus arteriosus stenting (reverse Potts shunt) and another underwent atrial septostomy and stenting. Conclusions: Notwithstanding the progress in medical therapy, IPAH continues to represent a serious challenge, particularly in the paediatric population, with the need for lung transplantation and significant mortality.

Pulmonary hypertension in paediatrics. A feasible approach to bridge the gap between real world and guidelines

Pulmonary hypertension (PH) is quite infrequent in paediatric age and its most common aetiologies include idiopathic pulmonary arterial hypertension, PH related to congenital heart diseases, bronchopulmonary dysplasia (chronic lung disease), persistence of pulmonary hypertension of the newborn, and congenital diaphragmatic hernia. The developed for adult patients PH classification shows limitations when applied to paediatric subjects, since the underlying causes are markedly different between the two ages. In 2011, the Pulmonary Vascular Research Institute Panama Task Force outlined the first specific paediatric pulmonary hypertensive vascular disease diagnostic classification, including 10 main categories and 109 subcategories, thus testifying PH complex pathophysiology during newborns/children growth and development. The unique, distinctive features of paediatric PH were recognized also during the fifth World Symposium on Pulmonary hypertension in 2013 and then confirmed in the recent 2018 sixth World Symposium. For the sake of uniformity, an attempt to adapt the adult classification to paediatric patients was made. However, all these commendable classifications are very complex and may be not of quick comprehension for clinicians. A clinical simpler and simplified method is now suggested, comprising only five groups: Neonatal, Cardiac, Developmental, Idiopathic, and Syndromic PH. This approach is not aimed at replacing the already existing classifications, but is mainly based on the kind of specialized physician (neonatologist, paediatric cardiologist, paediatrician, pulmonologist, general practitioner) who first faces and looks after the child with suspected PH. What is dramatically known is that paediatric PH is a severe disease which, when untreated or undertreated, may lead to increased morbidity and mortality.