title: Nocturnal Hypoxemia Due to Obstructive Sleep Apnea Is an Independent Predictor of Poor Prognosis After Myocardial Infarction.
abstract: Obstructive sleep apnea (OSA) is an important risk factor for the development of cardiovascular diseases including myocardial infarction (MI). The aim of this study was to investigate the effects of OSA on prognosis after MI, and to determine which specific measures of OSA severity best predicted outcomes.
  
  
  
  We performed a prospective study, in which 112 patients without a prior diagnosis of sleep apnea underwent comprehensive polysomnography within a median of 7 days after MI. Patients were followed up at 6-monthly intervals (±2 weeks) for a total of 48 months. Patients classified with central apnea (n=6) or those using continuous positive airway pressure (n=8) after polysomnography were excluded from analyses. The primary end point was major adverse cardiac events, including death from any cause, recurrent MI, unstable angina, heart failure, stroke, and significant arrhythmic events. Forty of 98 patients (41%) had OSA (apnea-hypopnea index ≥15 events/h). OSA patients had higher major adverse cardiac event rates when compared to those without OSA (47.5% versus 24.1%; χ(2)=5.41, P=0.020). In a multivariate model that adjusted for clinically relevant variables including age, left ventricular ejection fraction, diabetes mellitus, oxygen desaturation index, and arousal index, significant hypoxemia, as defined by nocturnal nadir oxygen saturation ≤85%, was an independent risk factor for major adverse cardiac events (hazard ratio=6.05, P=0.004) in follow-up 15 months after baseline.
  
  
  
  Nocturnal hypoxemia in OSA is an important predictor of poor prognosis for patients after MI. These findings suggest that routine use of low-cost nocturnal oximetry may be an economical and practical approach to stratify risk in post-MI patients.
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN Pulmonary Department of Beijing An Zhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Xie
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Fatima H
authors.initials: FH
authors.lastname: Sert Kuniyoshi
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Naima
authors.initials: N
authors.lastname: Covassin
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Prachi
authors.initials: P
authors.lastname: Singh
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Apoor S
authors.initials: AS
authors.lastname: Gami
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Shihan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: C Anwar A
authors.initials: CA
authors.lastname: Chahal
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing An Zhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN somers.virend@mayo.edu.
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000401:mortality; D001145:Arrhythmias, Cardiac / Q000401:mortality; D045422:Continuous Positive Airway Pressure / Q000401:mortality; D005260:Female; D006333:Heart Failure / Q000401:mortality; D006801:Humans; D000860:Hypoxia / Q000401:mortality; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality*; D017286:Polysomnography; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000401:mortality; D020521:Stroke / Q000401:mortality
keywords: hypoxemia; major adverse cardiac event; myocardial infarction; obstructive sleep apnea