846 Pulmonary Arterial Hypertension as a Sequela of Untreated Obstructive Sleep Apnea in a Patient with Prader-Willi Syndrome

Abstract

Introduction Prader-Willi Syndrome (PWS) is a complex neurogenetic disorder characterized by hypotonia, behavioral problems, endocrinopathies, sleep and respiratory abnormalities. Morbidity and mortality in the PWS population is attributable to obesity, cardiovascular problems, and sleep apnea. We report a patient with PWS presenting with pulmonary arterial hypertension (PAH) due to untreated obstructive sleep apnea (OSA). Report of case(s) Our patient is a 17-year-old female with a past medical history of PWS, scoliosis, obesity (BMI 52.46), hypogonadotropic hypogonadism, and type II diabetes. Baseline echocardiogram (ECHO) performed at age 9 revealed an estimated right ventricular systolic pressure (eRVSP) of 32mmHg above right atrial pressure (RAP), tricuspid regurgitation (TR) at 2.8 m/sec with no interventricular septal flattening (IVSF) and right ventricle (RV) systolic dysfunction suggestive of mild PAH. Given significant scoliosis the patient did not qualify for growth hormone therapy. She underwent a polysomnogram (PSG) at age 14 showing severe obstructive sleep apnea; apnea-hypopnea index (AHI) of 22.6 (oAHI 22.6). Patient was subsequently lost to follow up until presenting in acute respiratory failure at age 17. She required endotracheal intubation and was extubated to bilevel PAP (BPAP) with inability to wean off BPAP. At that time an ECHO revealed eRVSP of 55 mmHg above RAP, IVSF, TR at 3.7 m/sec, and RV systolic dysfunction suggestive of moderate to severe PAH and developing right sided heart failure. A PAP titration PSG during this admission revealed hypoxemia with oxygen saturation less than 90% (O2 nadir 70%) 12.6% of total sleep time (TST) and hypoventilation (transcutaneous CO2 max of 57 mmHg with an elevation above 50 mmHg for 100% of TST). Using an inspiratory PAP (IPAP) of 24 cmH2O and expiratory PAP (EPAP) of 14 cmH20 with supplemental O2 of 4LPM the respiratory events and hypoxemia resolved but there was persistence of hypoventilation. Tadalafil was initiated for PAH and BPAP therapy for OSA. Follow up visits 4- and 8-weeks post discharge shows improving PAH (TR 3.6 m/sec, eRSVP 52 mmHg, and mild IVSF) due to BPAP and tadalafil therapies. Conclusion This case highlights the importance of treating OSA in patients with PWS to prevent cardiorespiratory complications and reduce morbidity and mortality. Support (if any) None

Sleep Consequences of Prader-Willi Syndrome

“…There is also an increased risk of death from cardiopulmonary causes in those with the maternal disomy 15 subtype, although the mechanism for this is unknown [47]. Pulmonary hypertension, a known consequence of untreated OSA, is also reported in patients with PWS [49]. Other consequences of untreated OSA include increased risk of cardiovascular events and metabolic disease [50].…”