title: Symptoms of sleep apnoea in chronic heart failure--results from a prospective cohort study in 1,500 patients.
abstract: BACKGROUND
  In patients with chronic heart failure, sleep-disordered breathing (SDB) is a common co-morbidity worsening prognosis. The aim of this study was to investigate whether assessment of specific symptoms can elucidate presence of SDB in these patients.
  
  
  METHODS
  A prospective questionnaire scoring investigation on possible symptoms of sleep apnoea (nocturia, fatigue, daytime sleepiness, snoring, nocturnal sweating, witnessed apnoea's, nap) was conducted in 1,506 consecutive patients with stable chronic heart failure (LVEF ≤45%, NYHA ≥2). Afterwards, polysomnography or polygraphy, capillary blood gas analysis, echocardiography, and cardiopulmonary exercise testing were performed.
  
  
  RESULTS
  Adjusted for all significant covariates, snoring (p < 0.01) was the only symptom independently associated with OSA, while witnessed apnoeas (p = 0.02) and fatigue (p = 0.03) independently predicted for CSR. As additional parameters, higher BMI (threshold 26.6; p < 0.01) and higher pCO(2) (threshold 37.6 mmHg; p < 0.01) were independently associated with OSA and male gender (p < 0.001) and lower pCO(2) (threshold 35.0 mmHg; p < 0.001) with CSA. Cumulative questionnaire score results did not sufficiently (OSA--sensitivity 0.40, specificity 0.74; CSA--sensitivity 0.57, specificity 0.59) predict SDB.
  
  
  CONCLUSIONS
  Although in chronic heart failure patients with either OSA or CSA specific symptoms are apparent, combining clinical data, demographic data, and capillary blood gas analysis results appears favourable to determine the presence of SDB.
authors.affiliation: Department of Cardiology, Heart and Diabetes Centre North Rhine-Westphalia, Ruhr University Bochum, Bad Oeynhausen, Germany. akleemeyer@hdz-nrw.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Bitter
authors.forename: Nina
authors.initials: N
authors.lastname: Westerheide
authors.forename: Sajid Mohammed
authors.initials: SM
authors.lastname: Hossain
authors.forename: Christian
authors.initials: C
authors.lastname: Prinz
authors.forename: Dieter
authors.initials: D
authors.lastname: Horstkotte
authors.forename: Olaf
authors.initials: O
authors.lastname: Oldenburg
mesh_terms: D000368:Aged; D015992:Body Mass Index; D002639:Cheyne-Stokes Respiration / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D005858:Germany; D006306:Health Surveys; D006333:Heart Failure / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017286:Polysomnography; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D020182:Sleep Apnea, Central / Q000175:diagnosis / Q000453:epidemiology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology; D011795:Surveys and Questionnaires