Ankle-Brachial Index Test Ordering Guidelines

Essential Components of the ABI Order

The American Heart Association recommends specifying "Ankle-Brachial Index Test" as the procedure name, including clinical indication for the test, and requesting bilateral measurements to establish baseline and confirm diagnosis 1
The American College of Cardiology suggests measuring systolic pressures in both arms and both ankles, including posterior tibial and dorsalis pedis arteries, to calculate the ratio of ankle to brachial systolic pressure 2

The American Heart Association recommends ordering the measurement sequence as: first arm, first PT artery, first DP artery, other PT artery, other DP artery, and other arm, and if the systolic blood pressure of the first arm exceeds the second arm by >10 mm Hg, remeasuring the first arm 4

For diagnostic purposes, the American College of Cardiology suggests using the higher ankle pressure to calculate the ABI, which improves specificity 2
For patients with suspected non-compressible vessels, the American Heart Association recommends including an order for toe-brachial index as an alternative 1

The American College of Cardiology defines normal ABI as 0.91-1.40, borderline as 0.91-0.99, abnormal as ≤0.90, and non-compressible arteries as >1.40 5

Failing to order bilateral measurements could miss unilateral disease, according to the American Heart Association 1
Not specifying measurement of both PT and DP arteries could miss disease affecting only one vessel, as noted by the American College of Cardiology 2
The American Heart Association warns against overlooking the need for toe-brachial index in patients likely to have calcified vessels 1