Obstructive sleep apnea and self-reported functional impairment in revascularized patients with coronary artery disease in the RICCADSA trial

Purpose: Daytime sleepiness, a frequent symptom of obstructive sleep apnea (OSA), can impact functional status. In patients with coronary artery disease (CAD) and concomitant OSA, the distinction between sleep-related functional impairment from underlying CAD versus OSA is unclear. This study evaluated the impact of OSA on sleep-related functional impairment in patients with CAD and compared the effect of 1-year continuous positive airway pressure (CPAP) use on change in impairment between those with and without excessive daytime sleepiness (EDS) and OSA. We hypothesized that sleep-related functional impairment is impacted by EDS independent of OSA in patients with CAD. Methods: One hundred five CAD patients without OSA and 105 with moderate-to-severe OSA from the RICCADSA trial were matched on disease severity and included in the current substudy. Of those with OSA, 80 were allocated to CPAP. Functional Outcomes of Sleep Questionnaire (FOSQ) score < 17.9 corresponded to sleep-related functional impairment. Results: Following revascularization, CAD patients with and without OSA frequently report sleep-related functional impairment (35% and 27.3%, respectively; p =.29). Moderate-to-severe OSA was not related to baseline FOSQ scores < 17.9 in regression analyses; EDS was (OR 4.82, 95% CI 2.12–11.0; p <.001). CPAP use significantly improved FOSQ scores from baseline to 1-year follow-up in OSA patients with EDS (17.2 ± 2.0 to 18.15 ± 1.7, p =.002) despite suboptimal adherence. Conclusions: Sleep-related functional impairment may be reflective of persistent EDS, independent of OSA. Diagnosing OSA and initiating treatment are worthwhile in individuals with CAD and EDS, as both are important to guide appropriate therapy in patients with CAD