title: Auto-titrating continuous positive airway pressure therapy in patients with chronic heart failure and obstructive sleep apnoea: a randomized placebo-controlled trial.
abstract: OBJECTIVE
  Obstructive sleep apnoea (OSA) is highly prevalent in patients with chronic heart failure (CHF) and may contribute to CHF progression. We aimed to determine whether treatment of OSA with continuous positive airway pressure (CPAP) would improve subjective and objective measures of heart failure severity in patients with CHF and OSA.
  
  
  RESULTS
  Twenty-six patients with stable symptomatic CHF and OSA were randomized to nocturnal auto-titrating CPAP or sham CPAP for 6 weeks each in crossover design. Study co-primary endpoints were changes in peak VO(2) and 6 min walk distance. Secondary endpoints were changes in left ventricular ejection fraction, VE/VCO(2) slope, plasma neurohormonal markers, and quality-of-life measures. Twenty-three patients completed the study protocol. Mean CPAP and sham CPAP usage were 3.5 +/- 2.5 and 3.3 +/- 2.2 h/night, respectively (P = 0.31). CPAP treatment was associated with improvements in daytime sleepiness (Epworth Sleepiness Score 7 +/- 4 vs. 8 +/- 5, P = 0.04) but not in other quality-of-life measures. There were no changes in other study endpoints.
  
  
  CONCLUSIONS
  In patients with CHF and OSA, auto-titrating CPAP improves daytime sleepiness but not other subjective or objective measures of CHF severity. These data suggest that the potential therapeutic benefits of CPAP in CHF are achieved by alleviation of OSA rather than by improvement in cardiac function.
authors.affiliation: Cardiovascular Research, Centre for Cardiovascular Science, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK. lindsay.smith@ed.ac.uk
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Smith
authors.forename: Marjorie
authors.initials: M
authors.lastname: Vennelle
authors.forename: Roy S
authors.initials: RS
authors.lastname: Gardner
authors.forename: Theresa A
authors.initials: TA
authors.lastname: McDonagh
authors.forename: Martin A
authors.initials: MA
authors.lastname: Denvir
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Douglas
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011788:Quality of Life; D012606:Scotland; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000628:therapy; D016896:Treatment Outcome