Background: There has been growing evidence associating sleep disordered breathing (SDB) with cardiovascular events. However, the impact of SDB on long-term outcome in patients with acute coronary syndrome (ACS) has not been fully evaluated. Methods: We performed an overnight cardio-respiratory monitoring in 361 patients with ACS who were successfully treated with percutaneous coronary intervention between December 2004 and November 2009. Patients with an apnea-hypopnea index≥5/hour were considered to have SDB. We defined major adverse cardiovascular events (MACE) as cardiovascular death, non-fetal myocardial infarction, stroke and admission for congestive heart failure. Patients were followed for a mean period of 3.8 years. Results: Comorbidity of SDB with ACS was found in 195 patients (54%). MACE-free survival rate was significantly lower in patients with SDB (76% vs. 89%, p=0.0084). Multivariate logistic regression analysis identified SDB (hazard ratio: 2.03, 95% CI: 1.02 to 4.06, p=0.045) and reduced cardiac systolic function (Ejection fraction < 45%) (hazard ratio: 3.42, 95% CI: 1.80 to 6.49, p<0.001) as independent predictors of MACE. Conclusions: Our study showed a high prevalence of SDB among patients with ACS and SDB appeared to be a valuable predictor for clinical outcome in them. This suggests that earlier diagnosis and intervention for SDB should be considered in patients with ACS.
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