Ankle-Brachial Index (ABI) measurement is a simple, easily reproducible and accessible test that can accurately identify the presence of peripheral vascular disease. Peripheral vascular disease is a condition in which the arteries of the feet or hands are narrowed. Studies show that patients with peripheral angiopathy have an increased risk of heart attacks and strokes.
Blood pressure in the upper and lower extremities is measured during the test. The subject is lying down. Blood pressure is then measured at all four extremities using a cufflink and a doppler device. In some cases it may be helpful to measure the pressure and after stress test in a treadmill. After the above measurements are taken, the ankle-brachial index of the subject is measured. An ABI < 0.9 is considered pathological and may be indicative of the presence of stenosis in the lower extremities.
Peripheral vascular disease, like coronary artery disease, can have no symptoms unless it is at an advanced stage. So it is necessary to look for those who are at increased risk for its appearance.
- Smokers or former smokers over 50 years old
- Diabetics
- Patients with hypertension
- Those with elevated lipids
- People over 70 years old.
And of course patients reporting symptoms suspected of having peripheral vascular disease. These symptoms may be pain or cramping in the lower extremities during walking that disappears in rest (intermittent claudication). Even lower extremity wounds that are not easily healed or not at all. Cold lower extremities compared to the rest of the body.
An ankle-brachial index between 0.9 and 1.3 is considered normal. Values below 0.9 are indicative of peripheral vascular disease. Specific values below 0.4 indicate a severe degree of peripheral vascular disease. While values of 0.41 - 0.9 are indicative of the presence of small or moderate degree of peripheral artery disease and may be accompanied by intermittent claudication. Values ranging from 0.91 to 0.99 are considered to be marginal and in the presence of indications it may be required to measure ABI after stress. Finally, values above 1.3 (or 1.4 from other researchers) show hard vessels and usually occur in patients suffering from diabetes mellitus or chronic renal failure.
The measurement of abnormal ankle-brachial index is the trigger for further monitoring of the cardiovascular system and risk factors. As mentioned above, patients suffering from peripheral artery disease have an increased risk of developing coronary heart disease or stroke. Therefore, a complete cardiac examination is needed to assess the presence of coronary heart disease or the presence of vascular disease elsewhere in the vascular system. In addition, cardiac risk factors (arterial hypertension, dyslipidemia, smoking, obesity, sedentary life) should be evaluated and appropriate guidelines should be given to control them. Finally, further angiological examination may be required to better assess the extent of peripheral artery disease.