title: Importance of treadmill exercise time as an initial prognostic screening tool in patients with systolic left ventricular dysfunction.
abstract: BACKGROUND
  We sought to determine whether treadmill exercise time may be of value as an initial prognostic screening tool in ambulatory patients with impaired systolic function who are referred for cardiopulmonary exercise testing.
  
  
  RESULTS
  We studied 2231 adult systolic heart failure patients (27% of whom were women) who underwent cardiopulmonary stress testing using a modified Naughton protocol. We assessed the value of treadmill exercise time for prediction of all-cause death and a composite of death or United Network for Organ Sharing status 1 heart transplantation. During a mean follow-up of 5 years, 742 patients (33%) died. There were 249 United Network for Organ Sharing status 1 heart transplants (11%). Treadmill exercise time was predictive of death and the composite outcome in both women and men, even after accounting for peak oxygen consumption and other clinical covariates (adjusted hazard ratio of lowest versus high sex-specific quartile for prediction of death 1.70, 95% confidence interval 1.05 to 2.75, P=0.03; for prediction of the composite outcome, 1.75, 95% confidence interval 1.15 to 2.66, P=0.009). For a 1-minute change in exercise time, there was a 7% increased hazard of death (eg, comparing 480 to 540 seconds, hazard ratio =1.07, 95% confidence interval 1.02 to 1.12, P=0.004).
  
  
  CONCLUSIONS
  Because cardiopulmonary stress testing is not available in every hospital, treadmill exercise time with a modified Naughton protocol may be of value as an initial prognostic screening tool.
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic and Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
authors.forename: Eileen
authors.initials: E
authors.lastname: Hsich
authors.forename: Eiran Z
authors.initials: EZ
authors.lastname: Gorodeski
authors.forename: Randall C
authors.initials: RC
authors.lastname: Starling
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.forename: Hemant
authors.initials: H
authors.lastname: Ishwaran
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lauer
mesh_terms: D000328:Adult; D000368:Aged; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000401:mortality*