BEST-CLI is a study for people with peripheral arterial disease (PAD).

What is peripheral arterial disease and who is at risk?

Peripheral arterial disease (PAD) is a condition in which plaque builds up in the blood vessels that carry blood to arms and legs. About 3-10% of people have PAD and this number increases to 15-20% in those over 70 years of age. PAD is particularly common in individuals who smoke or have diabetes.1,2 Some patients with PAD develop critical limb ischemia (CLI). In CLI, blood vessels that deliver blood to the leg and foot are so narrowed by plaque buildup (atherosclerosis) that the foot cannot get enough blood. CLI can cause foot pain at rest, foot and leg ulcerations, and lead to gangrene and loss of the leg.

How is peripheral arterial disease treated?

CLI is typically treated with revascularization procedures (creating detours around or through the narrowed or blocked arteries) to improve blood flow to the leg and foot. There are two types of revascularization procedures that can be used to treat the CLI: open surgery and endovascular treatment.

  • Open Surgery

    During this surgery, a doctor takes your own leg vein and connects it to a healthy artery above the blockages and then to an artery in your leg below the blockages. The grafted vein goes around (bypasses) the blocked part of the artery. This bypass provides a new pathway for blood to your leg and foot. Some people do not have a leg vein that can be used. In these individuals, an artificial graft is used.

  • Endovascular Treatment

    During this procedure, a thin flexible tube (catheter) is inserted through an artery in the groin or arm and carefully guided into the artery that is narrowed. Once the tube reaches the narrowed artery, a small balloon at the end of the tube is inflated. The balloon may remain inflated from 20 seconds to 3 minutes. The pressure from the inflated balloon presses fat and calcium deposits (plaque) against the wall of the artery to improve blood flow. Once the fat and calcium buildup is compressed, a small, expandable wire-mesh tube called a stent is sometimes inserted into the artery to hold it open. The use of stents has not been studied specifically in patients with critical limb ischemia, and is therefore considered investigational (new). Plaque removing devices may also be used to remove plaque in the blockages.

What will happen in the study?

If you are interested in participating in the BEST-CLI study, you will be asked to come to a local BEST-CLI study site:

  • For further tests
  • To answer questions about your health
  • To learn more about the study
If you choose to participate, you will be assigned by chance (as in the flip of a coin) to receive either surgery or the endovascular procedure.

After the procedure, you will need to return to your BEST-CLI physician for follow-up exams at: 

  • 1 month
  • 3 months
  • 6 months
  • 12 months
  • 18 months
  • 24 months and annually thereafter.

You will also receive phone calls from the study nurse at 30, 42, 54, 66 and 78 months.

There are 160+ medical centers participating in this study. BEST-CLI expects to enroll 2,100 participants across the United States, Canada, and additional countries to be in this study. The physicians chosen to participate in BEST-CLI were selected because they have previous experience and are skilled at performing the procedures.

Your doctor can tell you more about this study and answer any questions you may have. If you agree to take part in the study you will be asked to sign a consent form. Your doctor will then tell you whether or not you are eligible to participate based on your clinical condition.

All information collected throughout this study will remain strictly confidential. Your name and your records will not be given out without your consent.


1. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg. Jan 2007;45 Suppl S:S5-67.

2. Selvin E, Erlinger TP. Prevalence of and risk factors for peripheral arterial disease in the United States: results from the National Health and Nutrition Examination Survey, 1999-2000. Circulation. Aug 10 2004;110(6):738-743.