Does calculation of ankle brachial pressure index need revision?

Peripheral arterial disease (PAD) is a commonly encountered but a commonly under-diagnosed condition in clinical practice. Ankle brachial pressure index (ABI) is a widely used procedure in its detection. It is also a very good prognostic marker not only of PAD but also of mortality. According to the current guidelines ABI of a side i.e. either the left or the right, is the quotient of the higher of the systolic blood pressures (SBP) of the two ankle arteries of that limb (either the anterior tibial artery or the posterior tibial artery) and the higher of the two brachial SBP of upper limbs. With the currently existing method of ABI calculation, considering only the higher of the SBP of the two ankle arteries, a distal stenosis of the ankle arterial system with the lower SBP, may be missed. We suggest a modification to the currently existing of calculating ABI. The method has been termed by us as the low ankle pressure method. In this method the lowest ankle pressure between the two ankle arteries of a particular side is to be the numerator and the denominator could be the same as before. A study or a series of studies comparing our proposed method with the current one are needed to test its clinical utility.