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CLEVER is a 3 arm, unblinded, multicenter randomized clinical trial with approximately 35 enrolling centers in the U.S. and Canada. The primary endpoint for CLEVER is exercise treadmill test performance using a graded treadmill test protocol. Secondary endpoints include community-based walking, quality of life, cost effectiveness, and a number of surrogates of cardiovascular disease risk (body mass index, waist circumference, blood pressure, lipids, glucose tolerance, and plasma fibrinogen levels).

The population is individuals with proximal arterial obstruction (aortoiliac) and moderate to severe claudication determined on a graded treadmill test. Therefore, it is a population for whom stent treatment is an accepted standard of care.

There are three study treatment groups: optimal medical care (OMC), OMC plus stent, and OMC plus supervised exercise. A sample size of 217 participants is required to achieve adequate study power.

Data are collected at baseline, 6 months, and 18 months, and the total duration of the study for participants is 18 months. All study participants receive cilostazol medication without charge for the duration of their participation in the study. They also receive a binder with information about home exercise and other health topics such as diet. Risk factors are reviewed and managed with the participants' doctors in order to reduce risk of future cardiovascular events.

In the only randomized clinical trial that examined supervised exercise compared with angioplasty, participants who received angioplasty showed much better ankle-brachial index results than exercise participants (figure 1), but participants in the supervised exercise group experienced more improvement in treadmill test walking (figure 2) [Perkins JMT, et al. Eur J Endovas Surg 1996;11:409-413.].

Exercise is a systemic therapy, with numerous beneficial effects on the cardiovascular system such as lowering blood pressure, improving serum lipid profiles, weight loss, and improvement of mood. Stent placement is a local therapy. The fundamental question posed by the CLEVER Study is: Are individuals with aortoiliac insufficiency and claudication better treated by relieving the local problem, arterial obstruction, by placing a stent, or are they better served by teaching them to exercise and live fundamentally healthier lives?

Researchers interested in participating the CLEVER study please contact Dr. Joselyn Cerezo or Dr. Timothy Murphy at (401) 444-1739.