title: CPAP effect on recurrent episodes in patients with sleep apnea and myocardial infarction.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is linked to increased cardiovascular risk, but the association between OSA and myocardial infarction (MI) remains controversial. Our objectives were to compare the frequency of OSA in patients with acute MI and in a population-based sample of control subjects, and to evaluate the impact of CPAP on recurrent MI and coronary revascularization.
  
  
  METHODS
  Case-control study with a 6-year follow-up of the case cohort. 192 acute MI patients and 96 matched control subjects without coronary artery disease (CAD) (ratio 2:1). After overnight polysomnography, CPAP was recommended if apnea-hypopnea index (AHI) ≥ 5, and a mean daily use >3.5h/day was considered necessary to maintain the treatment. Lipids, fasting glucose, blood pressure, spirometry, comorbidity and current treatment were also registered. End-points were recurrent MI or need of revascularization.
  
  
  RESULTS
  OSA was an independent predictor of MI, with odds ratio 4.9 (95% confidence interval [CI] 2.9-8.3, p=0.017). 63 MI patients without OSA, 52 untreated patients with OSA and 71 OSA patients treated with CPAP were included in the follow-up study. After adjustment for confounding factors, treated OSA patients had a lower risk of recurrent MI (adjusted hazard ratio 0.16 [95%CI 0.03-0.76, p=0.021]) and revascularization (adjusted hazard ratio 0.15 [95%CI 0.03-0.79, p=0.025]) than untreated OSA patients, and similar to non-OSA patients.
  
  
  CONCLUSIONS
  Mild-severe OSA is an independent risk factor for MI. Risk of recurrent MI and revascularization was lower in OSA patients who tolerated CPAP.
authors.affiliation: Servicio de Neumología, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain; CIBER Enfermedades Respiratorias (CIBERES), Spain. Electronic address: fgr01m@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Garcia-Rio
authors.forename: Alberto
authors.initials: A
authors.lastname: Alonso-Fernández
authors.forename: Eduardo
authors.initials: E
authors.lastname: Armada
authors.forename: Olga
authors.initials: O
authors.lastname: Mediano
authors.forename: Vanesa
authors.initials: V
authors.lastname: Lores
authors.forename: Blas
authors.initials: B
authors.lastname: Rojo
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Lahera
authors.forename: Isabel
authors.initials: I
authors.lastname: Fernández-Navarro
authors.forename: Carlos
authors.initials: C
authors.lastname: Carpio
authors.forename: Teresa
authors.initials: T
authors.lastname: Ramírez
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D017286:Polysomnography / Q000379:methods; D011446:Prospective Studies; D012008:Recurrence; D016037:Single-Blind Method; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D016896:Treatment Outcome
keywords: CPAP; Myocardial infarction; Prognosis; Revascularization; Sleep apnea