Relationship between severity of obstructive sleep apnea and adverse cardiac outcomes in non-diabetic patients presenting with myocardial infarction

Previous studies that have reported an association between obstructive sleep apnea and adverse cardiac events were confounded by a high prevalence of diabetes mellitus. We investigated the relationship between obstructive sleep apnea and the occurrence of major adverse cardiac events in non-diabetic patients who presented with ST-segment elevation myocardial infarction. A total of 41 patients who underwent overnight sleep screening within 5 days after admission for myocardial infarction from January 2007 to December 2008 were identified. Major adverse cardiac events—defined as a composite of cardiac death, non-fatal myocardial infarction, hospitalization for angina and congestive heart failure at 5-year follow-up—were determined. The patients were divided into two groups: those who experienced major adverse cardiac events and those who did not. In the overall cohort, the prevalence of obesity was 4.9 %. A total of 13 (31.7 %) patients had major adverse cardiac events. The mean apnea–hypopnea index was 25.4 ± 20.3. The group that experienced major adverse cardiac events had a higher apnea–hypopnea index than the group that did not (36.1 ± 21.0 vs 20.4 ± 18.2; P = 0.016). After adjusting for the resolution of ST-segment elevation and the use of a glycoprotein IIb/IIIa inhibitor, logistic regression analysis revealed that the apnea–hypopnea index remained an independent predictor of major adverse cardiac events (odds ratio 1.044; 95 % confidence interval 1.003–1.086; P = 0.033). In non-diabetic patients, the severity of obstructive sleep apnea was associated with the occurrence of major adverse cardiac events at 5-year follow-up after ST-segment elevation myocardial infarction.