Objectives: To describe the clinical presentation of pediatric pulmonary arterial hypertension (PAH) and the intricacies of how to classify pediatric PAH according to the Venice classification.
Study design: Children (n = 63) seen at a national referral center for pediatric PAH underwent a diagnostic work-up for diagnosis of pulmonary hypertension (PH) and associated conditions and for assessment of the explanatory role of associated conditions for the PH. Subsequently, PH was classified.
Results: In 18 patients (29%), no associated conditions were identified; they were classified as having idiopathic PAH. In 45 patients (71%), > or = 1 associated conditions were detected: congenital heart defects (CHD, n = 40), connective tissue disease (CTD, n = 2), disorders of respiratory system and/or hypoxemia (RSH, n = 17), and chronic thromboembolic disease (CTE, n = 1). Patients were classified according to the condition judged to be primarily explanatory for the PH. In 11 of 45 patients with associated conditions, the PH was not sufficiently explained by these conditions; these patients were classified as having idiopathic-like PAH. In 17 of 40 cases of CHD and 9 of 17 cases of RSH, these conditions were not sufficiently explanatory for the PH. Syndromal abnormalities were frequent (43%). Ultimately, classification revealed idiopathic (-like) PAH (n = 29; 46%), PAH-CHD (n = 23; 37%), PAH-CTD (n = 2; 3%), PH-RSH (n = 8; 12%), and CTE-PH (n = 1; 2%).
Conclusion: Pediatric PH frequently presents with associated conditions and syndromal abnormalities. However, detailed evaluation of this complex presentation reveals that associated conditions are not always explanatory for the PH.