Pulmonary arterial hypertension in the pediatric age

Pulmonary hypertension is defined as a mean pulmonary artery pressure more than 25 mmHg at rest or 30 mmHg on exercise. Pathogenesis of pulmonary hypertension is recognized to be multifactorial: vasoconstriction, proliferation, inflammation, and thrombosis. The main point in the clinical management is to assess the potential causes, the degree of functional and hemodynamic impairment and the available therapeutic options. Treatment of children with idiopathic pulmonary hypertension is similar to that of adults, but the results are often difficult to predict, with clinical deterioration being very rapid in early symptomatic patients. However, the availability of chronic vasodilator therapy, in particular epoprostenol, has led to a significant improvement in survival of children with idiopathic pulmonary hypertension and oral vasodilator agents are currently being evaluated. Moreover, lung transplantation is, nowadays, a reality even in children. Survival for patients with idiopathic pulmonary hypertension undergoing lung transplantation is approximately 65% at 1 year and 45% at 5 years. Accepted indications are severe clinical deterioration (New York Heart Association class III or IV) despite available medical treatments including intravenous epoprostenol. Timing for listing the patient is a difficult issue that should take into account possible markers of poor prognosis on medical therapy together with mortality rate of lung transplantation, local organ availability and mean waiting time on the list before transplantation.