Obstructive sleep apnea as a risk factor for coronary events or cardiovascular death

Abstract

Purpose: This study aims to determine whether obstructive sleep apnea independently increases the risk of coronary events, including death from cardiovascular causes.

Methods: We conducted an observational cohort study among consecutive patients >or=50 years of age who were referred during 1997-2001 to the Yale Center for Sleep Medicine for suspected sleep-disordered breathing and were followed longitudinally for subsequent coronary events or cardiovascular death. Each study participant underwent an overnight polysomnography; obstructive sleep apnea was defined as an apnea-hypopnea index >or=5/h. The composite outcome during a mean duration of follow-up of 2.9 years was myocardial infarction, coronary artery revascularization procedures (angioplasty, stent placement, or coronary artery bypass graft surgery), or death from cardiovascular causes.

Results: Among 1,436 enrolled patients, 1,024 (71%) had an apnea-hypopnea index >or=5/h. In an unadjusted analysis, obstructive sleep apnea was associated with an increased risk of coronary events or cardiovascular death (hazard ration (HR) 2.57, 95% confidence interval (CI) 1.39-4.72, P = 0.003). After adjustment for traditional cardiovascular risk factors (including body mass index and hypertension), obstructive sleep apnea retained a statistically significant association with this composite outcome (HR 2.06, 95% CI 1.10-3.86, P = 0.024).

Conclusion: Obstructive sleep apnea increases the risk of coronary events or death from cardiovascular causes.