title: Prognostic significance of declining ankle-brachial index values in patients with suspected or known peripheral arterial disease.
abstract: BACKGROUND
  Peripheral arterial disease (PAD) is a risk factor for cardiovascular events. This study assessed the prognostic significance of repeated ankle-brachial index (ABI) measurements at rest and after exercise in patients with PAD receiving conservative treatment.
  
  
  METHODS
  In a cohort study of 606 patients (mean age 62+/-12 years, 68% male), ABI at rest and after exercise was measured at baseline and after 1 year. Patients with reductions in ABI were divided into three equally-sized groups (minor, intermediate and major reductions) and were compared to patients without reductions. During a mean follow-up of 5+/-3 years, all-cause mortality, cardiac events, stroke and progression to kidney failure were noted.
  
  
  RESULTS
  Death was recorded in 83 patients (14%) of which 49% were due to cardiac causes. Non-fatal myocardial infarction occurred in 38 patients (6%), stroke in 46 (8%) and progression to kidney failure in 35 (6%). By multivariate analysis, patients with major declines in resting (>20%) and post-exercise (>30%) ABI were at increased risk of all-cause mortality (HR: 3.3, 95% CI: 1.5-7.2, HR: 3.0, 95% CI: 1.4-6.4, respectively), cardiac events (HR: 3.1, 95% CI: 1.3-7.2, HR: 2.4, 95% CI: 1.1-5.6, respectively), stroke (HR: 4.2, 95% CI: 1.6-10.4, HR: 3.9, 95% CI: 1.4-10.2, respectively) and kidney failure (HR: 2.7, 95% CI: 1.1-7.5, HR: 6.9, 95% CI: 1.5-31.5, respectively), compared to patients with no declines in ABI.
  
  
  CONCLUSIONS
  This study shows that major 1-year declines in resting and post-exercise ABI are associated with all-cause mortality, cardiac events, stroke and kidney failure in patients with PAD.
authors.affiliation: Departments of Cardiology, Erasmus MC Rotterdam, The Netherlands.
authors.forename: H H H
authors.initials: HH
authors.lastname: Feringa
authors.forename: S E
authors.initials: SE
authors.lastname: Karagiannis
authors.forename: O
authors.initials: O
authors.lastname: Schouten
authors.forename: R
authors.initials: R
authors.lastname: Vidakovic
authors.forename: V H
authors.initials: VH
authors.lastname: van Waning
authors.forename: E
authors.initials: E
authors.lastname: Boersma
authors.forename: G
authors.initials: G
authors.lastname: Welten
authors.forename: J J
authors.initials: JJ
authors.lastname: Bax
authors.forename: D
authors.initials: D
authors.lastname: Poldermans
mesh_terms: D000368:Aged; D000842:Ankle / Q000098:blood supply*; D001794:Blood Pressure; D001916:Brachial Artery / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000150:complications / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D013997:Time Factors