SLEEP-DISORDERED BREATHING - A NOVEL PREDICTOR OF ATRIAL-FIBRILLATIONAFTER CORONARY-ARTERY BYPASS-SURGERY

Background Sleep-disordered breathing is a common condition associated with nocturnal hypoxaemia, sympathetic activation and haemodynamic st ress that can trigger arrhythmias. We examined whether preoperatively diagnosed disordered breathing was associated with an increased incide nce of atrial fibrillation after coronary artery bypass surgery. Metho ds A sleep study was performed in 121 consecutive patients, who were m onitored prospectively until discharge from hospital after surgery, Di sordered breathing was defined as an apnoea-hypopnoea index (AHI) grea ter than or equal to 5 or an oxygen desaturation index (ODI) greater t han or equal to 5. All episodes of atrial fibrillation requiring pharm acological intervention or cardioversion were included in the analysis . Results Atrial fibrillation was diagnosed in 32% of patient with AHI greater than or equal to 5 (25 of 78) and in 18% of patients with AHI < 5 (7 of 39, P = 0.11), Similarly, atrial fibrillation was diagnosed in 39% of patients with ODI greater than or equal to 5 (19 of 49) and in 18% of patients with ODI < 5 (13 of 72, P = 0.02), In a multiple-l ogistic regression model including age, left ventricular function, aor tic cross clamp time, maximum postoperative level of lactate dehydroge nase and disordered breathing (ODI greater than or equal to 5), greate r age and disordered breathing were independent predictors of postoper ative atrial fibrillation. The relative risk of atrial fibrillation wa s 2.0 (95% confidence interval 1.1-3.8) for a 10-year increase in age and 2.8 (95% confidence interval 1.2-6.8) for disordered breathing (OD I greater than or equal to 5). Conclusion Pre-operatively diagnosed sl eep-disordered breathing with nocturnal hypoxaemia is an independent p redictor of atrial fibrillation after coronary bypass surgery.