The CLEVER (CLaudication: Exercise Vs. Endoluminal Revascularization) Study is sponsored by the National Institutes of Health’s(NIH) National Heart Lung and Blood Institute (NHBLI). The NHLBI is the premier sponsor of investigations that are internationally considered to be “best in class”. This study was the only multicenter randomized clinical trial for Peripheral Arterial Disease (P.A.D.) comparing supervised exercise with arterial stent placement. This is a major national effort to assure that the public and clinicians know what therapies are most effective, safest, and most cost-effective.

The CLEVER Study tested the effectiveness and safety of three different treatments for people with Peripheral Arterial Disease (P.A.D.) and it's main symptom, “claudication”. Eligible participants were randomly placed into one of the following three groups:

1. Optimal Medical Care group:

Participants in this group received the standard of care that those with intermittent claudication typically receive, including advice and referral if needed for smoking cessation, recommendations to exercise by walking as much as possible and supplies of the claudication medication cilostazol. Cilostazol is an approved medication that is known to be effective for many individuals with PAD and claudication.

2. Stent Placement group:

Participants in this group received care similar to the optimal medical care group and underwent placement of an arterial stent, a commonly used metallic coil, which is inserted via an X-Ray procedure opening the blocked artery in the affected leg.

3. Supervised Exercise group:

Participants in this group received care similar to the optimal medical care group plus access to supervised PAD exercise therapy classes for one hour three times a week for 26 weeks. Following the 26 weeks of supervised exercise, participants received monthly calls by a health educator to motivate them to continue to walk regularly at home, until the end of the study.

About Peripheral Arterial Disease (P.A.D.)

What is Peripheral Arterial Disease (P.A.D.)?
P.A.D. is a disease caused by the blockage of large arteries in the arms and legs. P.A.D. most commonly occurs when the arteries in your legs become narrowed or clogged with fatty deposits, or plaque. The buildup of plaque causes the arteries to harden and narrow, which is called atherosclerosis. When leg arteries are hardened and clogged, blood flow to the legs and feet is reduced. Some people call this poor circulation. People diagnosed with P.A.D. often experience leg muscle fatigue, cramping, numbness, or pain while walking, that resolves promptly with rest. This exertional discomfort in the leg muscles is known as “claudication”.

What is Claudication?
Claudication is the primary symptom of PAD, and can be experienced as pain, cramps, heaviness, fatigue or other symptoms that affect the muscle groups of the legs. Intermittent claudication is common in people diagnosed with P.A.D. Pain is caused by reduced blood flow to the muscles of the legs while walking or climbing stairs and is relieved by rest.

For additional information on P.A.D, please visit the following links:




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  • Alan T. Hirsch, M.D.
    Study Chair
  • Timothy P. Murphy, M.D.
    Principal Investigator
  • Donald E. Cutlip, M.D.
    Principal Investigator
  • David Cohen, M.D.
    Economics/Quality of Life
  • Judith Regensteiner, Ph.D.
    Exercise Training
  • Michael Steffes, M.D.
    Biochemistry Core Lab
  • Michael Jaff, D.O.
    Noninvasive Testing
  • Beth Lewis, Ph.D.
    Adherence to Physical Activity
  • Emile Mohler, M.D.
    Risk Factor Reduction
  • Joselyn Cerezo, M.D.
    CCC Project Manager
  • Niki C. Oldenburg, Dr.P.H.
    CCC Project Manager
  • Claudia Thum, M.A., DCC 
    Project Manager
  • Suzanne Goldberg, R.N., M.S.N.
    NHLBI Project Officer
  • Cheryl McDonald, M.D.
    NHLBI Deputy Project Officer