title: Arterial compliance across the spectrum of ankle-brachial index: the Multiethnic Study of Atherosclerosis.
abstract: OBJECTIVE
  A low ankle-brachial index is associated with cardiovascular disease and reduced arterial compliance. A high ankle-brachial index is also associated with an increased risk of cardiovascular events. We tested the hypothesis that subjects with a high ankle-brachial index demonstrate a lower arterial compliance. In addition, we assessed whether pulse pressure amplification is increased among subjects with a high ankle-brachial index.
  
  
  METHODS
  We studied 6814 adults enrolled in the Multiethnic Study of Atherosclerosis who were, by definition, free of clinical cardiovascular disease at baseline. Differences in total arterial compliance (ratio of stroke volume to pulse pressure), aortic and carotid distensibility (measured with magnetic resonance imaging and duplex ultrasound, respectively) were compared across ankle-brachial index subclasses (≤0.90, 0.91-1.29; ≥1.30) with analyses adjusted for cardiovascular risk factors and subclinical atherosclerosis.
  
  
  RESULTS
  Peripheral arterial disease was detected in 230 (3.4%) and high ABI in 648 (9.6%) of subjects. Those with high ankle-brachial index demonstrated greater aortic/radial pulse pressure amplification than those with a normal ankle-brachial index. In adjusted models aortic and carotid distensibility as well as total arterial compliance, were lowest among those with ankle-brachial index≤0.9 (p<0.01 vs. all), but were not reduced in subjects with an ankle-brachial index≥1.3.
  
  
  CONCLUSIONS
  Lower aortic, carotid and total arterial compliance is not present in subjects free of overt cardiovascular disease and with a high ankle-brachial index. However, increased pulse pressure amplification contributes to a greater ankle-brachial index in the general population and may allow better characterization of individuals with this phenotype.
authors.affiliation: Division of Cardiovascular Medicine, Ohio State University Heart and Vascular Center, Columbus, OH, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Lilly
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, MN, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Jacobs
authors.affiliation: Department of Biostatistics, University of Washington, Seattle, WA, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Kronmal
authors.affiliation: Departments of Radiology and Medicine, John Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.affiliation: Division of Preventive Medicine, University of California, San Diego, San Diego, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Criqui
authors.affiliation: Departments of Radiology and Medicine, John Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Joao
authors.initials: J
authors.lastname: Lima
authors.affiliation: Division of Preventive Medicine, University of California, San Diego, San Diego, CA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Allison
authors.affiliation: Cardiovascular Division, University of Minnesota, University of Minnesota, MN, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Duprez
authors.affiliation: Institute Biomedical Technology, Ghent University, Gent, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Segers
authors.affiliation: University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA; Philadelphia VA Medical Center, Philadelphia, PA, USA. Electronic address: julio.chirinos@uphs.upenn.edu.
authors.forename: Julio A
authors.initials: JA
authors.lastname: Chirinos
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D001011:Aorta / Q000503:physiopathology; D050197:Atherosclerosis / Q000208:ethnology / Q000503:physiopathology*; D001794:Blood Pressure; D017536:Carotid Artery, Common / Q000503:physiopathology; D015897:Comorbidity; D003187:Compliance; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D013318:Stroke Volume; D018616:Ultrasonography, Doppler, Duplex; D014481:United States; D059289:Vascular Stiffness
keywords: Atherosclerosis; Cardiovascular disease; Medial artery calcification; Vascular compliance