How Is Pulmonary Hypertension Characterised and Treated in Children With Trisomy 21? Observations From the TOPP Registry (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension)

Pulmonary hypertension is common in children with Trisomy 21, frequently with multifactorial aetiologies. Registry data provide better understanding of disease development, diagnostic workup and treatment patterns in children with Trisomy 21. TOPP (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension) is a centre-based, comprehensive registry. Patients aged between 3 months and 18 years at time of diagnosis were eligible if they met predefined haemodynamic criteria. Demographic data, clinical symptoms at presentation, diagnostic tools, etiology, hemodynamic data, treatment, and follow-up were collected from the data base. Differences between the Trisomy 21 group and the non-Trisomy 21 group were analysed by the non-parametric Mann-Whitney test. Categorical variables were compared using the chi-squared test, or Fisher's exact test in the case of low expected frequencies. Out of 531 children in the registry, 62 patients (11.7%) were diagnosed with Trisomy 21. Compared to children without Trisomy 21, those with Trisomy 21 were younger at diagnosis, and had more often an associated congenital heart disease. Clinical symptoms at diagnosis were similar in children with or without Trisomy 21. However, those with Trisomy 21 presented less frequently with dyspnea with exertion, but more frequently with cyanosis, either at rest or with exertion. A comprehensive diagnostic workup in all children with Trisomy 21 was not done. Children with Trisomy 21 had lower mean pulmonary artery pressure (median 50 mmHg, IQR 38-62) and similar indexed pulmonary vascular resistance (median 11.5 WU.m², IQR 7.4-18.4) compared to patients without Trisomy 21. Children with Trisomy 21 were treated less frequently with targeted therapies for pulmonary arterial hypertension and received less combination therapy. In children with Trisomy 21 and pulmonary hypertension, early systematic diagnostic work up is essential to obtain the correct underlying pathology and guides to appropriate treatment.