Clinical features of paediatric pulmonary hypertension: a registry study

Abstract

Background: Paediatric pulmonary hypertension, is an important cause of morbidity and mortality, and is insufficiently characterised in children. The Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension (TOPP) registry is a global, prospective study designed to provide information about demographics, treatment, and outcomes in paediatric pulmonary hypertension.

Methods: Consecutive patients aged 18 years or younger at diagnosis with pulmonary hypertension and increased pulmonary vascular resistance were enrolled in TOPP at 31 centres in 19 countries from Jan 31, 2008, to Feb 15, 2010. Patient and disease characteristics, including age at diagnosis and at enrolment, sex, ethnicity, presenting symptoms, pulmonary hypertension classification, comorbid disorders, medical and family history, haemodynamic indices, and functional class were recorded. Follow-up was decided by the patients' physicians according to the individual's health-care needs.

Findings: 362 of 456 consecutive patients had confirmed pulmonary hypertension (defined as mean pulmonary artery pressure ≥25 mm Hg, pulmonary capillary wedge pressure ≤12 mm Hg, and pulmonary vascular resistance index ≥3 WU/m(-2)). 317 (88%) patients had pulmonary arterial hypertension (PAH), which was idiopathic [IPAH] or familial [FPAH] in 182 (57%), and associated with other disorders in 135 (43%), of which 115 (85%) cases were associated with congenital heart disease. 42 patients (12%) had pulmonary hypertension associated with respiratory disease or hypoxaemia, with bronchopulmonary dysplasia most frequent. Finally, only three patients had either chronic thromboembolic pulmonary hypertension or miscellaneous causes of pulmonary hypertension. Chromosomal anomalies, mainly trisomy 21, were reported in 47 (13%) of patients with confirmed disease. Median age at diagnosis was 7 years (IQR 3-12); 59% (268 of 456) were female. Although dyspnoea and fatigue were the most frequent symptoms, syncope occurred in 31% (57 of 182) of patients with IPAH or FPAH and in 18% (eight of 45) of those with repaired congenital heart disease; no children with unrepaired congenital systemic-to-pulmonary shunts had syncope. Despite severe pulmonary hypertension, functional class was I or II in 230 of 362 (64%) patients, which is consistent with preserved right-heart function.

Interpretation: TOPP identifies important clinical features specific to the care of paediatric pulmonary hypertension, which draw attention to the need for paediatric data rather than extrapolation from adult studies.

Funding: Actelion Pharmaceuticals.