0568 Physiologic OSA Traits and CPAP Adherence Among Patients with Coronary Artery Disease and OSA

Abstract

Abstract Introduction Obstructive sleep apnea (OSA) is common in patients with coronary artery disease (CAD), but adherence to continuous positive airway pressure (CPAP) in this population is poor. Low arousal threshold (ArTH), a pathophysiologic OSA trait, is associated with low rates of regular CPAP use in sleep clinic populations. We aimed to determine whether ArTH or other physiologic OSA traits (i.e. pharyngeal collapsibility, muscle compensation, loop gain) are associated with CPAP adherence in patients with CAD and OSA. Methods A secondary analysis of a randomized controlled trial of OSA treatment in patients with CAD (RICCADSA) was performed. OSA (apnea hypopnea index, AHI≥5/hour) was assessed by polysomnography. Arousal threshold (% eupneic ventilation, %Ve), loop gain (LG), pharyngeal collapsibility (%Ve) and compensation (%Ve) were estimated from polysomnography using a validated method. Adherence to auto-titrated CPAP (hours/night) was obtained from machine downloads at 1, 3, 6, 12 and 24 months. Mixed modelling was used to assess the association between OSA traits and CPAP adherence. Results Participants (n=262) were 64.1±7.9 years old, with BMI of 29.2±4.2 and 86% were men. The mean AHI was 40.8±23.6 events/hour with oxygen nadir of 81.3±7.1%. The median (IQR) CPAP adherence (hrs/night) was 3.0 (0.9, 5.8) at 1-mo and 3.0 (0.0, 5.6) at 24-mo. Compared to reference studies, the CAD patients exhibited an elevated LG 0.63 (0.53, 0.79), similar ArTH (%Ve) of 117.5% (106.5%, 136.4%), higher collapsibility (%Ve) at 90.1% (82.3%, 94.8%) and lower compensation (%Ve) at 3.7% (-0.7%, 8.7%).Only increasing pharyngeal muscle compensation was associated with lower CPAP adherence (β -0.04, p-value 0.048), effect modified by pharyngeal collapsibility (Compensation x Collapsibility, β <0.01, p-value 0.042). Conclusion In this group of patients with CAD, increasing muscle compensation was associated with lower CPAP adherence. Physiologic OSA traits may provide insight into prediction of CPAP adherence among patients with OSA and CAD. Support Zinchuk: Parker B. Francis Fellowship Program in Clinical Research. Sands: American Heart Association. Peker: Swedish Research Council, Swedish Heart-Lung Foundation.