The ABI is a simple, non-invasive test, which measures the ratio of systolic blood pressure in the ankle to the systolic blood pressure in the upper arm. This is based on the idea that if blood pressure readings in the ankle are lower than those in the arm, a blockage in the arteries that provide blood from the heart to the ankle is suspected.An ABI range of 0.90 to 1.40 is considered normal. A person is considered to have PAD when the ABI is ≤ 0.90. However, PAD can be further graded as mild to moderate if the ABI is between 0.41 and 0.90, and severe if an ABI is less than 0.40. These categories can provide insight into the disease course. Furthermore, ABI values of 0.91 to 0.99 are considered borderline and values >1.40 indicate noncompressible arteries. If an ABI >1.40 is calculated, this could indicate vessel wall stiffness caused by calcification, which can occur in people with uncontrolled diabetes. Abnormally high ABIs (>1.40) are usually considered false negatives and thus, such results merit further investigation and higher-level studies. Individuals with noncompressible arteries have an increased risk of cardiovascular mortality within a two-year period.In individuals with suspected PAD with normal ABIs can undergo exercise testing of ABI. A baseline ABI is obtained prior to exercise. The patient is then asked to exercise (usually patients are made to walk on a treadmill at a constant speed) until claudication pain occurs (for a maximum of 5 minutes), after which the ankle pressure is again measured.
Research also suggests that low-dose rivaroxaban plus aspirin is effective as a new anti-thrombotic regimen for PAD.Cilostazol can improve symptoms in some. Pentoxifylline is of unclear benefit. Cilostazol may improve walking distance for people who experience claudication due to peripheral artery disease, but no strong evidence  suggests that it improves the quality of life, decreases mortality, or decreases the risk of cardiovascular events.Treatment with other drugs or vitamins are unsupported by clinical evidence, "but trials evaluating the effect of folate and vitamin B12 on hyperhomocysteinemia, a putative vascular risk factor, are near completion". Revascularization
After a trial of the best medical treatment outline above, if symptoms persist, patients may be referred to a vascular or endovascular surgeon. The benefit of revascularization is thought to correspond to the severity of ischemia and the presence of other risk factors for limb loss such as wound and infection severity. Angioplasty (or percutaneous transluminal angioplasty) can be done on solitary lesions in large arteries, such as the femoral artery, but may not have sustained benefits. Patency rates following angioplasty are highest for iliac arteries, and decrease with arteries towards the toes. Other criteria that affect outcome following revascularization are length of lesion and number of lesions. There does not appear to be long term advantages or sustained benefit to placing a stent following angioplasty in order to hold the narrowing of the subsartorial artery open. Atherectomy, in which the plaque is scraped off of the inside of the vessel wall (albeit with no better results than angioplasty).