Sleep disordered breathing in cardiac surgery patients: The NU-SLEEP trial

Sleep disordered breathing (SDB) is associated with lifestyle-related diseases and its treatment influence the prognosis of cardiac disease, but little investigation of SDB has been conducted in cardiac surgery patients.

A prospective study was performed in 1005 patients undergoing cardiac surgery. The primary endpoint was the severity of SDB determined from the apnea/hypopnea index. The secondary endpoints were patient background factors, cardiovascular risk factors, ejection fraction, atrial and brain natriuretic peptides, oxidative stress and inflammatory markers, and postoperative atrial fibrillation. While 227 patients (22.6%) did not have SDB, there were 361 patients (35.9%) with mild SDB, 260 patients (25.9%) with moderate SDB, and 157 patients (15.6%) with severe SDB. Patients with severe SDB had a lower ejection fraction and higher levels of atrial and brain natriuretic peptides than the other groups. Postoperative atrial fibrillation occurred in 28 patients without SDB (13.6%), 43 patients with mild SDB (13.5%), 74 patients with moderate SDB (31.9%), and 73 patients with severe SDB (52.5%), being significantly more frequent in the severe group than the other groups.

SDB was frequent in cardiac surgery patients. Activation of the renin-angiotensin-aldosterone system, postoperative atrial fibrillation atrial, and cardiac dysfunction were associated with severe SDB. Markers of inflammation and oxidative stress also increased as SDB became more severe.