Usefulness of an abnormal ankle-brachial index to predict presence of coronary artery disease in African-Americans.

We sought to determine the role of an abnormal ankle-brachial index (ABI) in an African-American population with suspected coronary artery disease (CAD) referred for diagnostic coronary angiography. In this population, an ABI < or =0.90 predicted the presence of > or =3-vessel or left main CAD with a sensitivity of 85% and specificity of 77%. However, a normal ABI did not predict absence of 1- or 2-vessel CAD. These results suggest that in this population, the ABI can be used to increase the pretest probability of severe CAD.