title: Bicycle testing as an alternative diagnostic tool in patients suspected of intermittent claudication.
abstract: BACKGROUND
  The ankle-brachial index (ABI) obtained after a treadmill challenge is often used to confirm the diagnosis of intermittent claudication (IC). However, some patients fail treadmill testing due to (temporary) orthopedic or neurologic comorbidity or fear of falling. The aim of this study was to evaluate the role of bicycle testing as an alternative for treadmill testing. It was hypothesized that ABIs obtained after bicycle tests were not different compared with values after standard treadmill testing.
  
  
  METHODS
  In this validation study, newly diagnosed IC patients (Rutherford 1-3) underwent a standard treadmill test (TT, "gold standard") and two bicycle protocols, one with a continuous resistance submaximal character (submaximal bicycle test, SBT) and a second with an incremental ramp form having a maximal character (maximal bicycle test, MBT). ABIs of both legs were obtained before and twice after each of these three different exercise tests. Healthy individuals matched for age and gender served as controls.
  
  
  RESULTS
  The study population consisted of 32 patients (68 ± 11 years, 21 men). ABIs of each leg (n = 64) obtained after TT correlated significantly with values obtained after either bicycle test (TT vs. SBT: r = 0.90, P < 0.001; TT vs. MBT: r = 0.88, P < 0.001). Drops in ABI after both types of exercise were significantly correlated (TT vs. SBT: r = 0.66, P < 0.001; TT vs. MBT: r = 0.32, P < 0.01). A 98% sensitivity and 86% specificity for diagnosis of IC was observed after the SBT. After the MBT, these values were 98% and 43%, respectively. Healthy controls (n = 13) demonstrated ABI values >0.9 after cycling in all tests.
  
  
  CONCLUSIONS
  Both submaximal and a maximal bicycle tests may serve as alternative noninvasive tools for detecting intermittent claudication. Bicycle tests can potentially be used for patients unable to perform a treadmill test.
authors.affiliation: Department of Surgery, Máxima Medical Centre, Veldhoven, The Netherlands; CAPHRI Research School, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, The Netherlands. Electronic address: hugo.fokkenrood@catharina-ziekenhuis.nl.
authors.forename: Hugo J P
authors.initials: HJ
authors.lastname: Fokkenrood
authors.affiliation: MMC Academy, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: Houterman
authors.affiliation: Department of Sports Medicine, Máxima Medical Centre, Veldhoven, The Netherlands.
authors.forename: Goof
authors.initials: G
authors.lastname: Schep
authors.affiliation: CAPHRI Research School, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Surgery, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.
authors.forename: Joep A W
authors.initials: JA
authors.lastname: Teijink
authors.affiliation: Department of Surgery, Máxima Medical Centre, Veldhoven, The Netherlands; CARIM Research School, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Marc R M
authors.initials: MR
authors.lastname: Scheltinga
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D001642:Bicycling; D016022:Case-Control Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D016138:Walking