Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 9 4 2015 10 13 174 178 EN Zinat Nadia-Hatmi Nourafshar Hospital, Tehran University of Medical Sciences, Tehran, Iran. Soheila Dabiran Curriculum Development Center, Tehran University of Medical Sciences, Tehran, Iran. Ahmad Sabouri-Kashani Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Zeynab Heidarzadeh Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Zeynab Darvishi Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Maedeh Raznahan Research Deputy Directorship of Medical Faculty, Tehran, Iran. 2015 10 13 2015 10 13 Background: Given the lack of consistency in the literature regarding the reliability of the ankle-brachial index (ABI) as a valid screening tool and an independent risk indicator of cardiovascular events and mortality, we compared it with angiography as a reference standard test. Methods: This case-control study, conducted between 2010 and 2011 in Tehran Heart Center, recruited 362 angiographically confirmed cases of coronary artery disease (CAD) and 337 controls. A standard protocol was used to measure the ABI and different CAD risk factors. Results: A low ABI had specificity of 99.7%, positive predictive value of 95.8%, negative predictive value of 49.8%, sensitivity of 64%, likelihood ratio of 24.07, and odds ratio (OR) of 22.79 (95%CI: 3.06-69.76). The role of the associated risk factors was evaluated with OR (95%CI), with the variables including gender 3.15 (2.30-4.30), cigarette smoking 2.72 (1.86-3.99), family history 1.72 (1.17-2.51), diabetes 1.66 (1.15-2.4), and dyslipidemia 1.38 (1.02-1.88). In a multivariate model, the following variables remained statistically significantly correlated with CAD [OR (95%CI)]: ABI 13.86 (1.78-17.62); gender 3.69 (2.43- 5.58); family history of CAD 2.18 (1.41-3.37); smoking 1.69 (1.08-2.64); age 1.04 (1.02-1.06). Conclusions: A low ABI had specificity of 99.7%; however, because of its low sensitivity (64%), we should consider CAD risk factors associated with a low ABI in order to use it as a first-line screening test. https://rhythm.tums.ac.ir/index.php/jthc/article/view/352 https://rhythm.tums.ac.ir/index.php/jthc/article/download/352/345