title: Effects of continuous positive airway pressure on cardiovascular outcomes in heart failure patients with and without Cheyne-Stokes respiration.
abstract: BACKGROUND
  Continuous positive airway pressure (CPAP) improves cardiac function in patients with congestive heart failure (CHF) who also have Cheyne-Stokes respiration and central sleep apnea (CSR-CSA). However, the effects of CPAP in CHF patients without CSR-CSA have not been tested, and the long-term effects of this treatment on clinical cardiovascular outcomes are unknown.
  
  
  RESULTS
  We conducted a randomized, controlled trial in which 66 patients with CHF (29 with and 37 without CSR-CSA) were randomized to either a group that received CPAP nightly or to a control group. Change in left ventricular ejection fraction (LVEF) from baseline to 3 months and the combined mortality-cardiac transplantation rate over the median 2.2-year follow-up period were compared between the CPAP-treated and control groups. For the entire group of patients, CPAP had no significant effect on LVEF, but it was associated with a 60% relative risk reduction (95% confidence interval, 2% to 64%) in mortality-cardiac transplantation rate in patients who complied with CPAP therapy. Stratified analysis of patients with and without CSR-CSA revealed that those with CSR-CSA experienced both a significant improvement in LVEF at 3 months and a relative risk reduction of 81% (95% confidence interval, 26% to 95%) in the mortality-cardiac transplantation rate of those who used CPAP. CPAP had no significant effect on either of these outcomes in patients without CSR-CSA.
  
  
  CONCLUSIONS
  CPAP improves cardiac function in CHF patients with CSR-CSA but not in those without it. Although not definitive, our findings also suggest that CPAP can reduce the combined mortality-cardiac transplantation rate in those CHF patients with CSR-CSA who comply with therapy.
authors.affiliation: Sleep Research Laboratory of the Toronto Rehabilitation Institute, Department of Medicine at the Toronto General Hospital (University Health Network), University of Toronto, Ontario, Canada.
authors.forename: D D
authors.initials: DD
authors.lastname: Sin
authors.forename: A G
authors.initials: AG
authors.lastname: Logan
authors.forename: F S
authors.initials: FS
authors.lastname: Fitzgerald
authors.forename: P P
authors.initials: PP
authors.lastname: Liu
authors.forename: T D
authors.initials: TD
authors.lastname: Bradley
mesh_terms: D000368:Aged; D002639:Cheyne-Stokes Respiration / Q000150:complications / Q000401:mortality / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000401:mortality / Q000628:therapy; D016019:Survival Analysis; D016896:Treatment Outcome; D016277:Ventricular Function, Left