The Claudication: Exercise vs Endoluminal Revascularization (CLEVER) Study is a prospective multicenter randomized clinical trial designed to compare the relative clinical and cost-effectiveness of invasive revascularization with stents to supervised exercise rehabilitation in a cohort with moderate to severe claudication due to aortoiliac insufficiency. The study is currently enrolling at twenty-eight sites in the US and Canada. Enrollment of 217 participants is planned, with data collected at baseline, six months, and 18 months. The primary study endpoint is maximum walking duration (MWD) on a graded treadmill test; secondary endpoints include community-based walking, markers of cardiovascular disease risk (body mass index, waist circumference, blood pressure, lipid profile, glucose tolerance, and plasma fibrinogen), health-related quality of life, and cost effectiveness. There are currently sixty randomized participants; recruitment is projected to end in July 2010 and final study results reported in June 2012.