0753 Predictors of Residual sleep apnea in OSA patients on PAP

Abstract

Abstract Introduction Positive airway pressure (PAP) is the first line therapy for patients with obstructive sleep apnea (OSA). However, clinical OSA may have multiple disease drivers beyond upper airway collapse, such as high loop gain and a low arousal threshold. The burden of residual sleep apnea in patients treated with PAP and it’s predictors remained to be fully defined. Methods Adult patients who were diagnosed with OSA through a split-night polysomnography (PSG) in the AASM accredited sleep center at the Beth Israel Deaconess Medical Center, Harvard Medical School and followed using the EncoreAnywhereTM system were prospectively included. Monthly visual/manual scoring of residual events was done. The ratio of patients with residual sleep apnea (defined as a manually-scored respiratory event index (REI) ≥ 15 times/hour in the 3rd month and 12th month were calculated. A linear regression model was used to explore the predictors of residual sleep apnea on PAP. Results One hundred and ninety five patients were included. In the 3rd month, there were 166 patients still on PAP. There were 74 (44.58%) with a residual AHI ≥ 15 times/h. In the 12th month, there were 93 patients still on PAP and 41 (44.09%) had residual AHI ≥ 15. In the short term, treatment CAHI (β= 0.511, SE=0.123, p=0.001), age (β= 0.123, SE=0.054, p=0.025), and hypertension (β= 3.627, SE=1.536, p=0.019) were the predictors for residual sleep apnea. In the long term, treatment CAHI (β= 0.598, SE=0.163, p=0.001), male gender (β= -5.117, SE=2.005, p=0.013) and baseline mean arousal duration (β= -0.601, SE=0.184, p=0.002) were predictors for residual sleep apnea. Conclusion There was a high percentage of patients with OSA on PAP who have residual sleep apnea. Treatment CAHI is a strong predictor, and may reflect high loop gain effects. Support (If Any) Category-I Strategic Research Award from the AASM Foundation to R. J. Thomas