Abstract: ObjectiveTo examine the relationship between ankle brachial index (ABI) and the extent of coronary stenosis and evaluate the usefulness of ABI to predict the extent of coronary stenosis in old patients.Methods118 patients with coronary angiography were examined by ABI and hemostatic factors evaluation in addition to history collection.ResultsABI was inversely and significantly associated with Gensini score. ABI reduced significantly (P<0.001) in the patients with 3-vessel or left main coronary artery disease (CAD). But there were no significant differences in ABI among the patients with no CAD, 1-vessel or 2-vessel CAD. The corresponding area under the ROC curve was 0.75±0.045, with 95% CI=0.67～0.84 (P<0.001) in ABI in 3-vessel or left main CAD. When ABI≤0.9, it had a relatively high specificity (89.1%) and sensitivity (55.6%) for predicting the presence of 3-vessel disease or left main CAD.ConclusionIn the old patients, ABI is inversely and significantly associated with the extent of coronary stenosis, and ABI≤0.9 has a relatively high specificity and sensitivity for predicting the presence of 3-vessel or left main CAD.

Key words: ankle-brachial index (ABI), coronary angiography, Gensini score, receiver-operating characteristic curves (ROC)