Prevalence and Impact of Undiagnosed OSA in Patients Needing Coronary Artery Bypass Grafting

Abstract

PURPOSE: To investigate the prevalence and impact of undiagnosed obstructive sleep apnea (OSA) in patients undergoing coronary artery bypass grafting (CABG) and to compare 3 different clinical survey methods: Epworth, Berlin, and Sleep Apnea Clinical Score. Secondary objectives were to study post-operative clinical outcomes. METHODS: Consecutive patients undergoing CABG were studied using the Embletta portable sleep monitor. Clinical data along with the three clinical surveys were collected and post-operative outcomes were recorded. RESULTS: For the 49 patients with complete clinical and follow-up data the average AHI was 20.9 (95% CI: [17.1, 24.6]). 82% of patients had an AHI > 10 (95% CI: [70%, 93%]) and 55% of patients had an AHI >15 (95% CI: [41%, 70%]). None of the clinical surveys had a strong correlation with AHI, and their positive post-test probabilities ranged from 52% of 68%. CONCLUSIONS: Over 80% of patients had an AHI > 10 suggesting significant undiagnosed OSA in this population. The low correlation between clinical scores and AHI values suggests that these surveys may not be well calibrated for this population. No impact on clinical outcomes was detected.