title: Heart rate significantly influences the relationship between atrial fibrillation and ankle-brachial index.
abstract: OBJECTIVE
  Both atrial fibrillation (AF) and vascular disease share several risk factors and the two diseases often coexist. The patients with AF were reported to have a decreased ankle-brachial index (ABI). However, ABI was also reported to have an inverse relationship with heart rate (HR). Because AF patients often have a transiently or persistently rapid HR, this study aimed to assess whether AF was significantly associated with decreased ABI and whether HR could significantly influence the relationship between AF and ABI.
  
  
  METHODS
  We included 166 AF and 1336 non-AF patients from subjects undergoing echocardiographic examinations. ABI was measured using an ABI-form device.
  
  
  RESULTS
  Compared to non-AF patients, AF patients had a decreased ABI (p<0.001). In a multivariate model, including covariates of age, sex, blood pressures, etc., the presence of AF was significantly associated with low ABI (β=-0.069, p=0.026). However, further adjustment for HR made this association disappear (p=0.971).
  
  
  CONCLUSIONS
  This study demonstrated that the presence of AF was associated with decreased ABI, but this association became insignificant after further adjustment for HR, which suggested HR could significantly influence the relationship between AF and ABI.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Po-Chao
authors.initials: PC
authors.lastname: Hsu
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wen-Hsien
authors.initials: WH
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chun-Yuan
authors.initials: CY
authors.lastname: Chu
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: cobeshm@seed.net.tw.
authors.forename: Ho-Ming
authors.initials: HM
authors.lastname: Su
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chee-Siong
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wen-Chol
authors.initials: WC
authors.lastname: Voon
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Wen-Ter
authors.initials: WT
authors.lastname: Lai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Sheng-Hsiung
authors.initials: SH
authors.lastname: Sheu
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D001281:Atrial Fibrillation / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D059289:Vascular Stiffness
keywords: Ankle-brachial index; Atrial fibrillation; Heart rate