0576 Impact of Obstructive Sleep Apnea on In-Hospital Mortality Due to Acute Myocardial Infarction - A Large Retrospective National Study of Veterans

Abstract

Abstract Introduction Ischemic preconditioning (IPC) is a phenomenon that refers to multiple, brief periods of myocardial ischemia followed by reperfusion. This counterintuitive preconditioning is thought to provide cardioprotection from subsequent prolonged ischemic events. Obstructive sleep apnea (OSA) may lead to IPC by frequent, recurrent short episodes of hypoxia and sympathetic stimulation. We hypothesized in patients who were admitted with acute myocardial infarction (MI), the presence of OSA was associated with improved survival during the hospitalization, likely due to IPC. Methods This is a retrospective cohort study utilizing national Veterans Health Administration (VHA) records. The cohort includes patients from 1999-2020 with a hospitalization for MI as the principal diagnosis. We confirm the OSA diagnosis using ICD9/10 codes. The primary outcome was in-hospital mortality during the index admission for acute MI. We reported the odds ratio (OR) of in-hospital mortality between with-OSA and without-OSA using logistic regression. We adjusted the OR (aOR) by age, gender, race, ethnicity, BMI, and Charlson Comorbidity index. Results Out of 4,237,444 veterans with any sleep diagnosis, 76,359 patients were hospitalized with a diagnosis of MI. We observed 30,116 with OSA (age, 64±10; BMI, 33±7) and 43,480 without OSA (age, 68±12; BMI, 29±6). The aOR of in-patient mortality was lower in with-OSA (n = 333[1.1%]; aOR, 1.86; 95% CI, 1.63 to 2.12) compared to without-OSA (n = 1,102[2.5%]; aOR, 2.02; 95% CI, 1.78 to 2.30). After stratifying the patients based on previous history of MI, the results remained the same. Conclusion We found that in patients admitted with acute MI, the OSA cohort was associated with lower mortality when compared to non-OSA cohort. We speculate that these differences may be attributed to IPC likely due to repetitive, chronic episodes of hypoxia in obstructive sleep apnea. Further research is warranted to elicit the clinical implications of ischemic preconditioning and OSA. Support (If Any) Culebras, A. Exploring the trail between cerebral ischemic aggravation and ischemic preconditioning. Obstructive sleep apnea leads the way. Sleep Medicine, Volume 67 ,2020, p 276-277Salman LA, Shulman R, Cohen JB. Obstructive sleep apnea, hypertension, and cardiovascular risk: epidemiology, pathophysiology, and management. Curr Cardiol Rep 2020;22(2):6