Ankle-brachial index (ABI) test
What is the ankle-brachial index (ABI) test?
The ankle-brachial index (ABI) test is a quick and noninvasive way for healthcare practitioners to know if a patient has peripheral artery disease.
During the test, a healthcare provider checks the blood pressure of specific arteries in the arms and ankles and uses an ultrasound device to listen to blood flow at the same time. The ABI is then calculated by dividing the higher systolic ankle blood pressure by the higher systolic arm blood pressure. A number between 1.0 and 1.4 is considered normal. Less than 0.9 is a sign of PAD, with lower values correlating to more severe PAD.
The ABI test results can tell a healthcare provider:
- The severity of PAD
- If the arms and legs are getting enough oxygen
- A patient’s risk of dying from a cardiovascular issue
- The severity of vascular injury after trauma
However, there are some limitations of the ABI test. For example, it cannot identify where the blocked or narrowed blood vessels are.
How does the ankle-brachial index (ABI) test improve healthcare?
Catching PAD early allows individuals to make lifestyle changes and receive treatment that reduces their risk of cardiovascular issues. Since the ABI test is an easy and noninvasive way for physicians to monitor for PAD, it allows them to catch the disease when it is in its early stages, which opens the door for prompt treatment and intervention.