Prevalence of Pulmonary Hypertension and Relation to Disease Severity in Children with Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) has been associated with pulmonary hypertension (PHTN), however the relationship between OSA severity and PHTN in children is not well understood. The purpose of this study is to examine the prevalence of PHTN in children with OSA using echocardiographic (ECHO) parameters and examine ECHO findings as they relate to severity of OSA.

Methods: A retrospective cohort study of subjects with OSA undergoing polysomnogram (PSG) and ECHO between 01/01/15 – 12/31/20 was performed. Subjects with PSG and ECHO > 30 days apart, and patients with significant structural or congenital heart disease were excluded. Comorbid conditions and surgical history were also collected for each patient. ECHO evidence of PHTN was defined as the presence of ≥ 2 of the following: tricuspid regurgitation (TR) velocity > 3 m/sec, pulmonary acceleration/ejection time (AT/ET) ratio < 0.3, left ventricular eccentricity index (EI) > 1.5, right ventricular (RV) dysfunction, and abnormal RV geometry. These ECHO parameters were compared to OSA severity by obstructive apnea-hypopnea index (AHI), % time with oxygen saturation < 90%, and % time with end-tidal carbon dioxide > 50 mmHg. Odds ratios were calculated for each comorbid condition to evaluate for possible risk factors of the development of PHTN.

Results: A total of 509 subjects were evaluated. TR jet velocity was adequate in only 12% of subjects. Overall, 4% of subjects were found to have ≥ 2 indicators of PHTN. AHI severity was actually higher in the group without significant PHTN findings (Table). AHI severity also did not correlate with worsening ECHO parameters. Worsening hypoxemia, hypercarbia on PSG did not correlate with ECHO indicators of PHTN (Figure). Odds ratios (OR, 95% CI) for comorbid conditions demonstrated that patients with a diagnosis of bronchopulmonary dysplasia (5.60, 2.14 – 14.67), gastroesophageal reflux disease (4.32, 1.65 – 11.32), and developmental delay (4.00, 1.65 – 9.72) had increased odds of developing PHTN in this cohort.

Conclusion: Significant evidence of PHTN was seen in only 4% of children with OSA. ECHO findings of PHTN do not correlate to PSG parameters of OSA disease severity. Comorbidities, particularly bronchopulmonary dysplasia, gastroesophageal reflux, and developmental delay, appear to be a risk factor for developing PHTN despite lower AHI in this patient cohort.