Pediatric Pulmonary Hypertension on the World Stage: Do We Need Separate Neonatal Guidelines?

Abstract

In comparison with adult disease, pediatric pulmonary hypertension (PH) and related pulmonary vascular disease (PVD) remain relatively understudied and poorly understood. Despite many advances over the past decades, PH continues to cause significant morbidity and mortality in diverse neonatal, pulmonary, cardiac, hematologic, and other systemic disorders of childhood. Despite some similarities, many aspects of PH in children are distinct from adult PH. Although new drug therapies are available for off-label use in pediatric PH, the long-term outcomes of children with severe PH often remain poor. Most clinical studies have emphasized the results of clinical trials in adult patients, yet PH in pediatrics can be devastating and often contributes to poor outcomes in diverse clinical settings in newborns, infants, and children. Of several major challenges addressed in the recent 6th World Symposium on Pulmonary Hypertension (WSPH), one goal was to explore major issues regarding the pathobiology, diagnostic assessment, management, and outcomes of diverse childhood diseases associated with pediatric PH. There are marked differences in the epidemiology of pediatric and adult PH, as well as very striking differences in function, structure, genetics, and responsiveness to therapies between adults and children with PH. Unfortunately, studies that address the safety and efficacy of PH therapies in children are rare, as most pharmaceutical studies have focused on the adult population and only in patients with a fairly limited range of associated conditions. Except for the use of inhaled nitric oxide therapy for neonates with persistent PH of the newborn (PPHN) as based on multicenter randomized trials, nearly all of the current therapies for children remain almost exclusively based on results from adult clinical trials and small case series of the use of PH-targeted therapies. Thus, pediatric PH has been understudied, and little is understood regarding the natural history, mechanisms of disease, and treatment of childhood PH, especially in the setting of neonatal and genetic developmental lung diseases.