title: The prognostic value of cardiopulmonary exercise testing in idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea, impaired gas exchange, and ultimate mortality.
  
  
  OBJECTIVE
  To test the hypothesis that maximal oxygen uptake during cardiopulmonary exercise testing at baseline and with short-term longitudinal measures would predict mortality in patients with idiopathic pulmonary fibrosis.
  
  
  METHODS
  Data from 117 patients with IPF and longitudinal cardiopulmonary exercise tests were examined retrospectively. Survival was calculated from the date of the first cardiopulmonary exercise test.
  
  
  RESULTS
  Patients with baseline maximal oxygen uptake less than 8.3 ml/kg/min had an increased risk of death (n = 8; hazard ratio, 3.24; 95% confidence interval, 1.10-9.56; P = 0.03) after adjusting for age, gender, smoking status, baseline forced vital capacity, and baseline diffusion capacity for carbon monoxide. We were unable to define a unit change in maximal oxygen uptake that predicted survival in our cohort.
  
  
  CONCLUSIONS
  We conclude that a threshold maximal oxygen uptake of 8.3 ml/kg/min during cardiopulmonary exercise testing at baseline adds prognostic information for patients with IPF.
authors.affiliation: Division of Respiratory Medicine, University of Calgary, Calgary, Canada.
authors.forename: Charlene D
authors.initials: CD
authors.lastname: Fell
authors.forename: Lyrica Xiaohong
authors.initials: LX
authors.lastname: Liu
authors.forename: Caroline
authors.initials: C
authors.lastname: Motika
authors.forename: Ella A
authors.initials: EA
authors.lastname: Kazerooni
authors.forename: Barry H
authors.initials: BH
authors.lastname: Gross
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Colby
authors.forename: Susan
authors.initials: S
authors.lastname: Murray
authors.forename: Galen B
authors.initials: GB
authors.lastname: Toews
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Martinez
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Flaherty
mesh_terms: D000368:Aged; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000378:metabolism*; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects
chemical_list: D010100:Oxygen