Prevalence of pulmonary hypertension in children with Prader-Willi Syndrome.

RATIONALE: Prader-Willi Syndrome (PWS) is associated with obesity and sleep-related breathing disorders (SRBD). Pulmonary hypertension (PH) is prevalent in children with SRBD. We sought to determine the PH prevalence in children with PWS and SRBDs and determine the association of PH with OSA severity and obesity. METHODS: A retrospective study of patients with PWS followed at Children's Hospital Los Angeles was performed. Data collected included demographics, body mass index (BMI), echocardiogram, cardiac catheterization (if present), and polysomnography (PSG) results. RESULTS: 37 patients with PWS had technically acceptable echocardiogram and PSG or chronic respiratory failure diagnosis; ten (27%) met criteria for PH. All patients with PH were obese and had SRBD with average OAHI of 21.9 ± 20 events/hour. Five patients had hypoventilation. The average age of first echocardiogram was 9.8 ± 2.8 years. The average age at PH diagnosis was 11.1 ± 3.9 years. The average TR jet was 2.8 ± 0.3 m/s. Four patients had septal flattening. One had cardiac catheterization with mean PA pressure 29 mmHg, PVR 3.7wu x m2, and RV systolic pressure 42 mmHg. Hypoventilation was associated with pulmonary hypertension (p = 0.003). There was no detectable association between presence of OSA, sleep related hypoxemia, elevated BMI or growth hormone therapy and the presence of PH. CONCLUSIONS: PH is relatively prevalent in children with PWS, particularly in those with hypoventilation. PH was identified in later childhood, after they had a diagnosis of SRBD. Our findings advocate for earlier and routine screening of PH particularly in those with hypoventilation.