Background and Aim: Cardiovascular disease is one of the main causes of mortality and morbidity around the world and because of insidious and chronic progression of arterioscleroses and coronary artery disease (CAD) and also correlation between peripheral arterial disease and CAD we evaluated ankle brachial index (ABI) as a predictive factor for early diagnosis of CAD.

Materials and Methods: Evaluation of ABI performed in patients who referred to cardiology department of Imam Khomeini Hospital for coronary angiography from April 2003 to May 2004. 100 patients selected for the study, 50 patients with CAD (at least one vessel significantly involved) and 50 patients with normal coronary arteries as control cases. Relation between ABI and CAD studied in the patients, also other variables such as age, sex, family history of CAD, diabetes mellitus, hypertension, hyperlipidemia, cigarette smoking and claudication were evaluated.

Results: The mean age in patients with coronary artery disease was 56±16 years old (66% male, 34% female) and in normal coronary patients was 52+15 years old (48% male, 52% female). The mean ABI in patients with abnormal coronary arteries was 1.07±0.028 and in cases with normal coronary arteries was 1.12±0.016 that was not significant (P= 0.128). In addition there was no significant value between ABI and other variables mentioned above. All patients with ABI≤ 0.9 (14% of patients) had CAD.

Conclusion: This study revealed that although an ABI≤ 0.9 has a high predictive value for CAD, the ABI itself can not be a sensitive predictor of CAD diagnosis because a large numbers of CAD patients had ABI more than 0.9. Hence this level of ABI can not rule out the presence of CAD in many patients.