title: Severe obstructive sleep apnea and outcomes following myocardial infarction.
abstract: OBJECTIVE
  We sought to determine the effect of severe obstructive sleep apnea (OSA) on long-term outcomes after myocardial infarction. We hypothesized that severe OSA was associated with lower event-free survival rate after ST-segment elevation myocardial infarction (STEMI).
  
  
  METHODS
  A total of 120 patients underwent an overnight sleep study during index admission for STEMI. Severe OSA was defined as apnea hypopnea index (AHI) ≥ 30, and non-severe OSA defined as AHI < 30.
  
  
  RESULTS
  Among the 105 patients who completed the study, 44 (42%) had severe OSA and 61 (58%) non-severe OSA. The median creatine kinase level and mean left ventricular systolic function were similar between the 2 groups. None of the 105 study patients had received treatments for OSA. Between 1- and 18-month follow-up, the severe OSA group incurred 1 death, 2 reinfarctions, 1 stroke, 6 unplanned target vessel revascularizations, and 1 heart failure hospitalization. In contrast, there were only 2 unplanned target vessel revascularizations in the non-severe OSA group. The incidence of major adverse events was significantly higher in the severe OSA group (15.9% versus 3.3%, adjusted hazard ratios: 5.36, 95% CI: 1.01 to 28.53, p = 0.049). Kaplan-Meier event-free survival curves showed the event-free survival rates in the severe OSA group was significantly worse than that in the non-severe OSA group (p = 0.021, log-rank test).
  
  
  CONCLUSIONS
  42% of the patients admitted with STEMI have undiagnosed severe OSA. Severe OSA carries a negative prognostic impact for this group of patients. It is associated with a lower event-free survival rate at 18-month follow-up.
authors.affiliation: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. mdclchr@nus.edu.sg
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Lee
authors.forename: See-Meng
authors.initials: SM
authors.lastname: Khoo
authors.forename: Mark Y
authors.initials: MY
authors.lastname: Chan
authors.forename: Hwee-Bee
authors.initials: HB
authors.lastname: Wong
authors.forename: Adrian F
authors.initials: AF
authors.lastname: Low
authors.forename: Qian-Hui
authors.initials: QH
authors.lastname: Phua
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.forename: Huay-Cheem
authors.initials: HC
authors.lastname: Tan
authors.forename: Tiong-Cheng
authors.initials: TC
authors.lastname: Yeo
mesh_terms: D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D018572:Disease-Free Survival; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D017286:Polysomnography / Q000379:methods; D011175:Positive-Pressure Respiration / Q000379:methods; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D016019:Survival Analysis; D013997:Time Factors