title: The Effect of Post-Exercise Ankle-Brachial Index on Lower Extremity Revascularization.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of post-exercise ankle-brachial index (ABI) on the incidence of lower extremity (LE) revascularization, cardiovascular outcomes, and all-cause mortality in patients with normal and abnormal resting ABI.
  
  
  BACKGROUND
  The clinical and prognostic value of post-exercise ABI in the setting of normal or abnormal resting ABI remains uncertain.
  
  
  METHODS
  A total of 2,791 consecutive patients with ABI testing between September 2005 and January 2010 were classified into group 1: normal resting (NR)/normal post-exercise (NE); group 2: NR/abnormal post-exercise (AE); group 3: abnormal resting (AR)/NE; and group 4: AR/AE. Abnormal post-exercise ABI was defined as a drop of >20% from resting ABI as per the American College of Cardiology/American Heart Association guidelines. The primary endpoint was incidence of LE revascularization. Secondary endpoints were major adverse cardiovascular events (MACE) and all-cause mortality. Associations between post-exercise ABI and outcomes were adjusted using multivariable Cox proportional hazard and propensity analyses.
  
  
  RESULTS
  Compared with group 1 (NR/NE), group 2 (NR/AE) had increased LE revascularization (propensity-matched adjusted hazard ratio [HR]: 6.63, 95% confidence interval [CI]: 3.13 to 14.04; p < 0.001) but no differences in MACE or all-cause mortality. When resting ABI was abnormal, group 4 (AR/AE) compared with group 3 (AR/NE), abnormal post-exercise ABI was still associated with increased LE revascularization (adjusted HR: 1.59, 95% CI: 1.11 to 2.28; p = 0.01), which persisted after propensity matching (adjusted HR: 2.32, 95% CI: 1.52 to 3.54; p < 0.001). Compared with group 1 (NR/NE) and after propensity matching, group 4 (AR/AE) had a significant increase in MACE (adjusted HR: 1.44, 95% CI: 1.09 to 1.90; p = 0.009) and a trend toward increased all-cause mortality (adjusted HR: 1.37, 95% CI: 0.99 to 1.88; p = 0.052); however, group 3 (AR/NE) did not.
  
  
  CONCLUSIONS
  Post-exercise ABI appears to offer both clinical (lower extremity revascularization) and prognostic information in those with normal and abnormal resting ABI.
authors: Medicine Institute, Department of Hospital Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Tarek A
authors: TA
authors: Hammad
authors: Medicine Institute, Department of Internal Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Jason A
authors: JA
authors: Strefling
authors: Medicine Institute, Department of Internal Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Paul R
authors: PR
authors: Zellers
authors: Heart and Vascular Institute, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Grant W
authors: GW
authors: Reed
authors: Medicine Institute, Department of Hospital Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Sridhar
authors: S
authors: Venkatachalam
authors: Heart and Vascular Institute, Department of Quantitative Health Science, Cleveland Clinic, Cleveland, Ohio.
authors: Ashley M
authors: AM
authors: Lowry
authors: Heart and Vascular Institute, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: Heather L
authors: HL
authors: Gornik
authors: Heart and Vascular Institute, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio.
authors: John R
authors: JR
authors: Bartholomew
authors: Heart and Vascular Institute, Department of Quantitative Health Science, Cleveland Clinic, Cleveland, Ohio.
authors: Eugene H
authors: EH
authors: Blackstone
authors: Heart and Vascular Institute, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio. Electronic address: shishem@ccf.org.
authors: Mehdi H
authors: MH
authors: Shishehbor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055109:Ankle Brachial Index; D016009:Chi-Square Distribution; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality; D005080:Exercise Test; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D011237:Predictive Value of Tests; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality
keywords: all-cause mortality; exercise ankle-brachial index; lower extremity revascularization; peripheral artery disease; prognosis