BACKGROUND: Patients with obstructive sleep apnea (OSA) experience intermittent hypoxia, hypercarbia, and sympathetic activation during sleep, which increases risk for paroxysmal atrial fibrillation and other cardiac arrhythmias. Whether patients with OSA experience increased episodes of atrial fibrillation after cardiac surgery is unclear. We examined whether patients at increased risk for OSA, assessed by the STOP-BANG (snoring, tired during the day, observed stop breathing during sleep, high blood pressure, body mass index more than 35 kg/m, age more than 50 years, neck circumference more than 40 cm, and male gender) questionnaire, had a higher incidence of new-onset postoperative atrial fibrillation after cardiac surgery. Because both postoperative atrial fibrillation and OSA increase resource utilization, we secondarily examined whether patients at increased OSA risk had longer duration of postoperative mechanical ventilation and intensive care unit (ICU) length of stay.
METHODS: With institutional review board approval, this retrospective observational study evaluated adult patients who underwent elective cardiac surgery requiring cardiopulmonary bypass between 2014 and 2015 with preoperative assessment of OSA risk using the STOP-BANG questionnaire. Patients with a history of atrial fibrillation were excluded. The association between the STOP-BANG score and postoperative atrial fibrillation was examined using a multivariable logistic regression model. Secondarily, we estimated the association between the STOP-BANG score and duration of initial intubation using multivariable linear regression and ICU length of stay using Cox proportional hazards regression. We also descriptively summarized the percentage of patients requiring tracheal reintubation for mechanical ventilation.
RESULTS: Of 4228 cardiac surgery patients, 1593 met inclusion and exclusion criteria. An increased STOP-BANG score was associated with higher odds of postoperative atrial fibrillation (odds ratio [95% confidence interval {CI}], 1.16 [1.09-1.23] per-point increase in the STOP-BANG score; P < .001). The STOP-BANG score was not associated with ICU length of stay (estimated hazard ratio [97.5% CI], 0.99 [0.96-1.03] per-point increase in the STOP-BANG score; P = .99) or duration of initial intubation (ratio of geometric means [97.5% CI], 1.01 [1.00-1.04]; P = .03; significance criterion [Bonferroni correction] < 0.025). One percent of patients required reintubation.
DISCUSSION: Increasing risk for OSA, assessed by STOP-BANG, was associated with higher odds of postoperative atrial fibrillation, but not prolonged duration of mechanical ventilation or ICU length of stay.
