Sleep apnea in patients undergoing coronary artery bypass grafting: Impact on perioperative outcomes

Sleep-disordered breathing is common in patients with coronary artery disease undergoing coronary artery bypass grafting. Sleep-disordered breathing is associated with increased perioperative morbidity, arrhythmias (e.g. atrial fibrillation) and mortality. This study investigated the impact of sleep-disordered breathing on the postoperative course after coronary artery bypass grafting, including development of atrial fibrillation. This prospective single-centre cohort study included adults undergoing coronary artery bypass grafting. All were screened for sleep-disordered breathing (polygraphy) and atrial fibrillation (electrocardiogram) preoperatively; those with known sleep-disordered breathing or atrial fibrillation were excluded. Endpoints included new-onset atrial fibrillation, duration of mechanical ventilation, time in the intensive care unit, and postoperative infection. Regression analysis was performed to identify associations between sleep-disordered breathing and these outcomes. A total of 508 participants were included (80% male, median age 68 years). The prevalence of any (apnea-hypopnea index ≥ 5 per hr), moderate (apnea-hypopnea index = 15-30 per hr) and severe (apnea-hypopnea index > 30 per hr) sleep-disordered breathing was 52.9%, 9.3% and 10.2%, respectively. All-cause 30-day mortality was 0.98%. After adjustment for age and sex, severe sleep-disordered breathing was associated with longer respiratory ventilation support (crude odds ratio [95% confidence interval] 5.28 [2.18-12.77]; p < 0.001) and higher postoperative infection rates (crude odds ratio 3.32 [1.45-7.58]; p < 0.005), but not new-onset atrial fibrillation or mortality. New-onset atrial fibrillation was significantly associated with postoperative infection and prolonged hospital stay. The significant associations between sleep-disordered breathing and several adverse outcomes after coronary artery bypass grafting support the need for preoperative sleep-disordered breathing screening in individuals undergoing cardiac surgery.