What is the expected ABI (Ankle-Brachial Index) in a patient with significant peripheral arterial disease?

The expected Ankle-Brachial Index (ABI) in a patient with significant peripheral arterial disease (PAD) is below 0.90. The ABI is a simple non-invasive test used to assess the blood flow to the limbs and to determine the presence of PAD.

In individuals with normal arterial function, the ABI typically ranges from 1.0 to 1.4, indicating adequate blood flow. An ABI value of less than 0.90 suggests significant arterial occlusion and is diagnostic for PAD. The lower the ABI, the more severe the disease; patients with ABIs below 0.90 are at higher risk for cardiovascular events and may experience symptoms such as claudication. For example, an ABI of 0.75 indicates moderate PAD, while an ABI of 0.50 or lower indicates severe disease.

An ABI value above 1.0 can be seen in patients with calcified, non-compressible vessels, often found in individuals with diabetes or chronic kidney disease, but this does not indicate PAD as it reflects a different issue. The range of 0.91 to 1.0 could imply borderline PAD, but it does not signify significant disease. Therefore, for significant PAD, an ABI below