title: Relationship between sleep apnoea and mortality in patients with ischaemic heart failure.
abstract: OBJECTIVE
  To determine whether the influence of sleep apnoea (SA) on the risk of death differs in patients with ischaemic and in those with non-ischaemic heart failure (HF).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Consecutive patients with HF with left ventricular ejection fraction < or =45% newly referred to the HF clinic between 1 September 1997 and 1 December 2004.
  
  
  METHODS
  Patients underwent sleep studies and were divided into those with moderate to severe SA (apnoea-hypopnoea index > or =15/h of sleep) and those with mild to no SA (apnoea-hypopnoea index <15/h of sleep). They were followed up for a mean of 32 months to determine all-cause mortality rate.
  
  
  RESULTS
  Of 193 patients, 34 (18%) died. In the ischaemic group, mortality risk adjusted for confounding factors was significantly higher in those with SA than in those without it (18.9 vs 4.6 deaths/100 patient-years, hazards ratio (HR) = 3.03, 95% CI 1.04 to 8.84, p = 0.043). In contrast, in the non-ischaemic HF group, there was no difference in adjusted mortality risk between those with, and those without, SA (3.9 vs 4.0 deaths/100 patient-years, p = 0.929).
  
  
  CONCLUSIONS
  In patients with HF, the presence of SA is independently associated with an increased risk of death in those with ischaemic, but not in those with non-ischaemic, aetiology. These findings suggest that patients with ischaemic cardiomyopathy are more susceptible to the adverse haemodynamic, autonomic and inflammatory consequences of SA than are those with non-ischaemic cardiomyopathy.
authors.affiliation: Sleep Research Laboratory of Toronto Rehabilitation Institute, University of Toronto, Toronto, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Yumino
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: J S
authors.initials: JS
authors.lastname: Floras
authors.forename: G E
authors.initials: GE
authors.lastname: Newton
authors.forename: S
authors.initials: S
authors.lastname: Mak
authors.forename: P
authors.initials: P
authors.lastname: Ruttanaumpawan
authors.forename: J D
authors.initials: JD
authors.lastname: Parker
authors.forename: T D
authors.initials: TD
authors.lastname: Bradley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002311:Cardiomyopathy, Dilated / Q000401:mortality; D002423:Cause of Death; D005260:Female; D006333:Heart Failure / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000401:mortality*; D017286:Polysomnography; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012891:Sleep Apnea Syndromes / Q000401:mortality*; D018487:Ventricular Dysfunction, Left / Q000401:mortality