title: Prevalence and clinical implications of newly revealed, asymptomatic abnormal ankle-brachial index in patients with significant coronary artery disease.
abstract: OBJECTIVE
  This study sought to evaluate the association between newly revealed abnormal ankle-brachial index (ABI) and clinical outcomes in patients with significant coronary artery stenosis.
  
  
  BACKGROUND
  Little is known about the prevalence and clinical implications of ABI in patients with no claudication or previous history of peripheral artery disease who undergo diagnostic coronary angiography.
  
  
  METHODS
  Between January 1, 2006, and December 31, 2009, ABI was evaluated in 2,543 consecutive patients with no clinical history of claudication or peripheral artery disease who underwent diagnostic coronary angiography. Abnormal ABI was defined as ≤0.9 or ≥1.4. The primary endpoint was the composite of death, myocardial infarction, and stroke over 3 years.
  
  
  RESULTS
  Of the 2,543 patients, 390 (15.3%) had abnormal ABI. Of the 2,424 patients with at least 1 significant stenosis (≥50%) in a major epicardial coronary artery, 385 (15.9%) had abnormal ABI, including 348 (14.4%) with ABI ≤0.9 and 37 (1.5%) with ABI ≥1.4. During a median follow-up of 986 days, the 3-year major adverse event rate was significantly higher in patients with abnormal than normal ABI (15.7% vs. 3.3%, p < 0.001). After multivariate analysis, abnormal ABI was identified as a predictor of primary endpoint (hazard ratio [HR]: 1.87; 95% confidence interval [CI]: 1.23 to 2.84; p = 0.004). After adjustment by propensity-score matching, abnormal ABI could predict adverse clinical events in patients with established coronary artery disease (HR: 2.40; 95% CI: 1.41 to 4.10; p = 0.001).
  
  
  CONCLUSIONS
  The prevalence of newly revealed abnormal, asymptomatic ABI among patients who have significant CAD on coronary angiography was 15.9%. The presence of abnormal ABI was associated with a higher incidence of adverse clinical outcomes over 3 years.
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Jong-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Seung-Whan
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Woo Seok
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Division of Biostatistics, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Seungbong
authors.initials: S
authors.lastname: Han
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Yong Kyu
authors.initials: YK
authors.lastname: Park
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Kwon
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Jeong Yoon
authors.initials: JY
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Young-Rak
authors.initials: YR
authors.lastname: Cho
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Gyung-Min
authors.initials: GM
authors.lastname: Park
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Ahn
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Won-Jang
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Duk-Woo
authors.initials: DW
authors.lastname: Park
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Kang
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Young-Hak
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Cheol Whan
authors.initials: CW
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Seong-Wook
authors.initials: SW
authors.lastname: Park
authors.affiliation: Division of Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea. Electronic address: sjpark@amc.seoul.kr.
authors.forename: Seung-Jung
authors.initials: SJ
authors.lastname: Park
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D058070:Asymptomatic Diseases; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000401:mortality; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000453:epidemiology; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology; D013997:Time Factors
keywords: ABI; CAD; CI; DP; HR; MI; PAD; PT; RR; ankle-brachial index; asymptomatic; clinical outcome; confidence interval; coronary artery disease; dorsalis pedis; hazard ratio; myocardial infarction; peripheral artery disease; posterior tibial; repeat revascularization