Ankle brachial pressure index (ABPI)— is a validated tool for the diagnosis of peripheral arterial disease. This investigation should be undertaken by an experienced operator using validated equipment.
An ABPI ratio of:
- 0.9 or less — suggests the presence of peripheral arterial disease.
- Between 1.0 and 1.4 —is considered normal.
- Greater than 1.4 —may suggest the presence of arterial calcification, such as in some people with diabetes, rheumatoid arthritis, systemic vasculitis, atherosclerotic disease, and advanced chronic renal failure. For values above 1.5, the vessels are likely to be incompressible, and the result cannot be relied on to guide clinical decisions.
- Care must be taken in interpreting ABPI results in people with these conditions, as they may be misleadingly high.
- Do not exclude a diagnosis of peripheral arterial disease in people with a normal or raised ABPI — if there is any doubt about a diagnosis of Chronic Limb Threatening Ischaemia seek advice from the Vascular Service.
Compression hosiery for venous or lymphatic disorders may be used where the ABPI is >0.8.
The finding of an ABPI of >1.4 in the absence of lower limb arterial symptoms does not require vascular surgical referral.
