What is a lower extremity arterial evaluation (LEA)?
A lower extremity arterial (LEA) evaluation, also known as ankle-brachial index (ABI), is a non-invasive test that is used to diagnose peripheral arterial disease (also known as peripheral vascular disease). During the diagnostic procedure, your provider will compare the systolic blood pressure in your legs to the blood pressure in the arms. The results of the test can determine the presence, location and severity of peripheral arterial disease (PAD).
If you have PAD, you may experience pain and numbness in your feet and legs due to reduced blood flow as plaque builds up in the arteries.
A LEA test cannot determine which vessels have plaque buildup.
Who is a candidate for a lower extremity arterial evaluation?Lower extremity arterial evaluations are performed on patients who are suspected of having or are at risk of developing peripheral arterial disease.
You are not a candidate for an ABI exam if you are unable to remain lying down with your face up for the duration of the exam or have blood clots in your legs.
Learn more about the risk factors for PAD.
What to expect during a lower extremity arterial evaluation?A LEA exam takes approximately 30 minutes. During the exam, your technician, typically a vascular sonographer, will position you on a table, facing upward. He or she will position blood pressure cuffs on your arms and legs and take your blood pressure in both locations. You may be asked to walk on a treadmill or ride a stationary bike, so your technician can take your blood pressure again after exercising.
Your provider will not give you your results right away. A Mercy Health cardiologist will review your test and follow up with next steps.The LEA (or ABI) is calculated for each leg. To calculate right leg ABI, your provider will divide the highest pressure in the right foot by the highest pressure in both arms.
What are the measurements for a LEA?
Patients with normal measurements should have less than 10 mm Hg difference in systolic pressure.
ABI values and what they mean:
- 1.0 - 1.4 - could indicate calcification in the vessels
- .9 - 1.4 - normal range - no treatment is necessary
- .8 - .9 - could indicate arterial disease is present
- .5 - .8 - indicates moderate arterial disease
- .5 or lower - indicates the presence of severe arterial disease
If you have over 1.4 or under .8 you will be referred to a Mercy Health peripheral arterial disease specialist for follow-up and treatment.
What are benefits of having a LEA evaluation?
A LEA evaluation can diagnose peripheral arterial disease in the early stages, so you can be treated and potentially reverse the damage in the legs. If left untreated, you may have to have a leg amputated.
What are risks associated with having an LEA evaluation?
Although, there are few risks associated with having a lower extremity arterial evaluation, you should not have a LEA if you have or are at risk for blood clots in your legs. You may also want to discuss different diagnostic options with your provider if you are experiencing severe leg pain.
Recovery from a LEA evaluation
You can go home and resume your normal activities right after the procedure. Your doctor will follow up with your results and give you next steps. If you have abnormal results, you may need further testing and treatment right away.