Change in type of sleep-disordered breathing from predominant central to obstructive sleep apnea following coronary artery bypass grafting.

We report the case of a 67-year-old overweight man with reduced left ventricular ejection fraction (LVEF) due to myocardial infarction. He had an implantable cardioverter defibrillator (ICD) for frequent episodes of ventricular tachyarrhythmia and was initiated into adaptive-servo ventilation therapy for severe central sleep apnea (CSA), which was not suppressed by continuous positive airway pressure (CPAP). Since he still had several episodes of appropriate ICD therapies, coronary angiogram was performed, and severe three-vessel disease was found. He then underwent coronary artery bypass grafting (CABG). After CABG, his LVEF did not improve (from 29 to 25%); however, the B-type natriuretic peptide level decreased (from 560 to 330 pg/mL). Although the apnea-hypopnea index did not change (49.4 before and 55.1/h after CABG), his CSA converted to predominant obstructive sleep apnea accompanied by a shortening of the lung-to-finger circulation time (from 43 to 29 s) 2 weeks after CABG, which was completely suppressed by CPAP. <Learning objective: Central sleep apnea (CSA) can be alleviated by treatments for heart failure. However, limited data are available regarding resolution of CSA after coronary revascularization. We describe a case whose predominant CSA converted to obstructive sleep apnea after surgical coronary revascularization without any improvements in systolic function. Coronary revascularization can alleviate CSA possibly through altering congestive status and may unmask obstructive phenotype in patients with severe coronary artery disease.>.