RESUMO
BACKGROUND AND OBJECTIVE: Acute chest pain (ACP) is a non-specific symptom that may be the expression of coronary artery disease (CAD). Atherosclerosis is usually present in more than one vascular territory. Ankle-brachial index (ABI) is a useful tool for the diagnosis of peripheral arterial disease (PAD). Our aim was to evaluate the value of ABI in patients with ACP when CAD is suspected. PATIENTS AND METHODS: We performed a cross-sectional study of 94 patients, mean age: 57.4 (12.2), admitted consecutively due to ACP with suspicion of CAD. ABI and presence of CAD were determined. RESULTS: CAD was present in 22 patients (23.4%) and absent in 72 (76.6%). Asymptomatic PAD (ABI < or = 0.9) was present in 6 patients (27.2%) of CAD group and in 7 patients (9.7%) of the non-CAD group. Significant difference was found in ABI based on the presence or not of CAD [0.95 (0.23) vs 1.17 (0.15), p<0.001]. The diagnostic value of ABI for CAD detection was evaluated: area under the ROC curve was 0.8 (IC 95%: 0.70-0.87) and optimal cut-off point was 0.8 (sensitivity=22.7% and specificity=98.6%). In the multivariate analysis, ABI was the best independent predictor of CAD (p<0.001). CONCLUSION: ABI is a simple, cheap and efficient method, which complements other conventional diagnostic methods in the recognition of patients with ACP due to CAD.