title: Prognostic value of the 6 min walk test and self-perceived symptom severity in older patients with chronic heart failure.
abstract: BACKGROUND
  The 6 min walk test (6-MWT) is a simple and popular test for evaluating functional status in patients with chronic heart failure (CHF). However, the prognostic value of the 6-MWT in a large, representative sample of CHF patients, and in patients with different degrees of left ventricular systolic dysfunction (LVSD) remains unclear.
  
  
  RESULTS
  Of an initial population of 1592 patients, 212 died representing a crude death rate of 13.3%. In surviving patients, the median time to follow-up period was 36.6 months [inter-quartile range (IQR) 28-45 months]. Five variables remained independent predictors of all-cause mortality; decreasing 6-MWT distance, self-perceived signs of breathlessness at night (SOBAN), beta-blocker usage, elevated log NT-proBNP, and reduced haemoglobin concentration. We also dichotomized our analysis by LVSD status (<or=mild LVSD or >mild LVSD). For patients with >mild LVSD, 6-MWT remained an important prognostic indicator but not in patients with <or=mild LVSD.
  
  
  CONCLUSIONS
  The 6-MWT is an important independent predictor of mortality in CHF patients, and this was especially evident in patients with >mild LVSD. The 6-MWT provides little prognostic utility in patients with <or=mild LVSD. While log NT-proBNP was the most potent independent predictor, an additive prognostic effect was evident with the additional selection of 6-MWT. Patients' self-perceived symptoms, especially SOBAN was an independent predictor of mortality in our patients.
authors.affiliation: Carnegie Research Institute, Leeds Metropolitan University, Beckett's Park Campus, Leeds LS6 3QS, UK.
authors.forename: Lee
authors.initials: L
authors.lastname: Ingle
authors.forename: Alan S
authors.initials: AS
authors.lastname: Rigby
authors.forename: Sean
authors.initials: S
authors.lastname: Carroll
authors.forename: Ron
authors.initials: R
authors.lastname: Butterly
authors.forename: Rod F
authors.initials: RF
authors.lastname: King
authors.forename: Carlton B
authors.initials: CB
authors.lastname: Cooke
authors.forename: John G J F
authors.initials: JG
authors.lastname: Cleland
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Clark
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology; D006801:Humans; D008297:Male; D011379:Prognosis; D012044:Regression Analysis; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000503:physiopathology; D016138:Walking / Q000502:physiology*