Sleep Apnea-Specific Hypoxic Burden and Postoperative Outcomes of Major Noncardiothoracic Surgery

Importance: Obstructive sleep apnea (OSA) is a highly prevalent and heterogeneous condition that predisposes to postoperative complications. Adequate metrics of OSA severity to stratify postoperative risk in a clinical setting are needed. Objective: To evaluate whether the sleep apnea-specific hypoxic burden (SASHB) is associated with postoperative cardiovascular (CV) complications and mortality among patients with OSA undergoing major noncardiothoracic surgery. Design, Setting, and Participants: Multicenter clinic-based cohort linked with a health administrative database involving adult patients diagnosed with OSA between May 2007 and December 2018 who underwent major noncardiothoracic surgery between OSA diagnosis and December 2024. Data were analyzed from January to December 2025. Exposure: SASHB defined as the area under the desaturation curve associated with sleep-related obstructive respiratory events. Main Outcomes and Measures: The primary outcome was a composite of stroke, atrial fibrillation, heart failure, myocardial infarction, venous thromboembolism, and all-cause mortality within 30 days of surgery. The association of SASHB and other OSA severity metrics with the primary outcome was investigated using univariable and multivariable analyses. Results: Among 2286 patients with OSA (median [IQR] age, 58 [49-66] years; 1472 [64.4%] men) who underwent major noncardiothoracic surgery a median (IQR) of 4.5 (1.9-7.5) years after OSA diagnosis, the primary outcome occurred in 80 patients (3.5%) within 30 days of surgery. The rate of events increased significantly from 1.6% (12 events) in patients with low SASHB (