Sleep Disorders

Obesity Hypoventilation Syndrome and Bariatric Surgery

Sleep-Disordered Breathing on Adverse Cardiovascular Outcomes After Bariatric Surgery (N = 1380)

2011 – 2019

MACE = major adverse cardiovascular event, MS-OSA = moderate/severe obstructive sleep apnea, OASH = obesity-associated sleep hypoventilation, OSA = obstructive sleep apnea

Patients undergoing polysomnography (PSG) prior to bariatric surgery at Cleveland Clinic from 2011–2018 were retrospectively examined and followed up from date of last surgery to 2019, including the perioperative period. Primary predictors include moderate-to-severe OSA, ie, apnea hypopnea index (AHI) > 15, and obesity-associated sleep hypoventilation (OASH), ie, body mass index (BMI ) ≥ 30 kg/m2 and either end-tidal CO2 ≥ 45 mm Hg or serum bicarbonate ≥ 27 mEq/L. MACE (coronary artery events, cerebrovascular events, heart failure, or atrial fibrillation)-free probability was compared using hazard ratios estimated from Cox proportional hazards models on 4 groups: OASH with moderate-to-severe OSA (N = 492), OASH-only (N = 442), moderate-to-severe OSA-only (N = 203), and a reference group without OASH or moderate-to-severe OSA (N = 243). Multivariable Cox proportional hazards models adjusting for age, sex, and BMI were fit on MACE survival. Analysis was performed based on an overall significance level of 0.05, using SAS software (version 9.4, Cary, NC). The sample comprised 1380 patients. Compared with the reference group, the OASH with moderate-to-severe OSA group had higher risk of MACE (HR = 2.53, 95% CI: 1.07-6.00, P = 0.035). Patients with moderate-to-severe OSA had higher risk of MACE than those with AHI < 15 (HR = 1.94, 95% CI: 1.20-3.13, P = 0.007). Patients with severe OSA had higher risk of MACE than those with AHI < 30 (HR = 2.01, 95% CI: 1.28-3.14, P = 0.002). For every 5-unit AHI increase, risk of MACE increased by 6% (HR = 1.056, 95% CI: 1.029-1.084, P < 0.001) with slight reduction in point estimates in adjusted models. These data support significant differences in the risk of MACE and MACE-free survival mitigated after consideration of obesity.