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

This study aims to determine whether obstructive sleep apnea independently increases the risk of coronary events, including death from cardiovascular causes. We conducted an observational cohort study among consecutive patients a parts per thousand yen50 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 a parts per thousand yen5/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. Among 1,436 enrolled patients, 1,024 (71%) had an apnea-hypopnea index a parts per thousand yen5/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). Obstructive sleep apnea increases the risk of coronary events or death from cardiovascular causes.