Guidelines for Pediatric Pulmonary Hypertension

The joint statement from the American Heart Association and American Thoracic Society for the guidelines of Pediatric Pulmonary Hypertension (PH) helps bring together the latest science in this field in order to craft practical guidelines for the care of this vulnerable patient population.¹ These guidelines will be an invaluable vade mecum for clinicians in the care of children with PH.

There have been previous consensus guidelines in the management of adults with PH. However, the present guidelines make an important distinction between PH in children and that seen in adults. This fundamental difference has profound implications for all aspects of care, including diagnosis, risk stratification, and therapies. Idiopathic PH tends to have the greatest overlap with PAH seen in adults. However, in many registries idiopathic PH accounts for the minority of cases of PH in children. Moreover, it is likely that such registries underestimate the prevalence of secondary forms of PH in children. A number of patient populations in pediatrics have very unique physiologies. These include the newborn with persistent PH, the young child with congenital diaphragmatic hernia, and the infants and young children with bronchopulmonary dysplasia. The time course for recovery and the optimal therapy for these patient populations can vary quite a bit.

PH, secondary to cardiac disease, is well established in all age groups. In adults this most commonly occurs secondarily to left heart failure or mitral valve disease. Conversely, in the congenital heart disease population, this can occur under a variety of scenarios. One of the more challenging groups is the patient population with unrecognized or unrepaired congenital heart lesions that result in intracardiac shunt. Historically, many of these children may have been denied reparative surgery for concerns that elevated pulmonary vascular resistance would result in deterioration after surgical repair of the intracardiac shunt. The present guidelines provide a roadmap for managing such patients. Fortunately, in the current era through appropriate risk stratification and use of adjunct therapies, many of these children can now safely undergo surgery and may be expected to have reasonable long-term outcome.

One particularly challenging issue for children with either left heart disease or left heart failure is the secondary development of PH. This can come in 2 forms: as a result of mitral stenosis or mitral insufficiency. Children commonly develop left atrial hypertension. This in turn leads to PH. The presence of PH raises the concern that if one could treat the underlying cardiac disease, such as mitral valve stenosis, that the child may be left with severe PH and, hence, surgical intervention and cardiopulmonary bypass may carry great risk. Fortunately, this set of guidelines provides some clear approaches to this complex patient population. Given current therapies, the great majority of these patients, even with significant secondary PH, should be able to be safely shepherded through surgery with the likelihood that PH would improve with time.

Another challenging scenario relates to the child with left ventricular dysfunction being considered for heart transplantation. Historically, these children may not have been offered transplantation, or may have required extraordinary interventions such as a heterotopic heart transplant. The present guidelines provide an approach to managing PH in these patients that should allow a great majority of them to safely undergo heart transplantation should that be the appropriate therapy.

One of the major advances in the management of PH has been the introduction of a number of medical therapies to improve outcomes. These have included inhaled continuous IV and oral therapies. Owing to the difficulty in executing randomized trials in this pediatric population, our management to date has largely been extrapolated from the adult experience. However, there has been renewed interest in prospective drug trials of PH therapies in children. This has been an area of focus for the Food and Drug Administration (FDA).² In particular, the FDA has been focused on phosphodiesterase inhibitors including sildenafil. Recently, the FDA raised some concern about the use of such agents in children. The present guidelines place these FDA interpretations in context and provide a sound and safe approach to the use of oral phosphodiesterase inhibitors in children with advanced PH. The experience of studying these agents in the PH population has certainly underscored the challenges of assessing pharmacotherapy in such high-risk pediatric patients.

One of the important themes of the present guidelines is that it is essential to create a multidisciplinary approach to the management of these patients. This would include expertise in management of lung disease as well as radiologic interpretation, since PH is by no means a cardiac or vascular disease only. There has been a recent effort around the country to establish such comprehensive pulmonary artery hypertension programs for children. These guidelines will only strengthen that effort to provide further expertise in some uniformity of care among the centers.

Pediatric pulmonary hypertension has long been considered a severe disease and in the minds of some clinicians, uniformly fatal. However, these guidelines underscore that prognosis has improved in recent years and likely will continue to improve in the years to come. As such, it is important for clinicians to know that children with PH should not be denied state-of-the-art care. Children who respond to short-term vasodilator drug therapy have been shown to have a 5-year survival rate of 90%.³ Even for those who do not respond to short-term vasodilator drug therapy, a fair proportion can survive 5 years. With the advances we have seen in the field in the last decade that should be expected to improve going forward. Undoubtedly, these guidelines will play a major role in the ongoing improvement and prognosis for PH. The American Heart Association is proud to partner with the American Thoracic Society to contribute to this advancement. These guidelines will be valuable in bringing together the pediatric hypertension community and setting a standard for excellence in care.