ORLANDO, FL—In patients with moderate to severe claudication and hemodynamically significant aortoiliac disease, supervised exercise improves treadmill walking performance more than stent revascularization. However, both exercise and stenting lead to significant improvements in various measures of quality of life (QOL) not seen with medical therapy alone, according to a study presented during a late breaking clinical trial session on Wednesday, November 16, 2011, at the American Heart Association Scientific Sessions and simultaneously published online ahead of print in Circulation.

For the CLEVER (Claudication: Exercise Versus Endoluminal Revascularization) study, Alan T. Hirsch, MD, of the University of Minnesota (Minneapolis, MN), and colleagues randomly assigned 111 patients with aortoiliac PAD to 1 of 3 treatments:

• Optimal medical therapy
• Optimal medical therapy plus supervised exercise
• Optimal medical therapy plus stenting

Medical therapy consisted of cilostazol 100 mg twice daily as tolerated plus advice about exercise and diet and monthly contact by a study coordinator. Supervised exercise consisted of 78 sessions (1-hour exercise sessions 3 times per week). Stent procedures employed self-expanding or balloon-expanding stents and intraprocedural or postprocedural antiplatelet therapy at the discretion of the operator.

Walking Times, QOL Improve with Intervention

At 6-month follow-up, the stented group improved more than the medical therapy group and the supervised exercise group for nearly every QOL measure. In addition, more patients in the stented group than the exercise group reported no claudication symptoms (42.5% vs. 21%).

For the primary endpoint of change in peak walking time, the greatest improvement was seen in the supervised exercise group and the least in the medical therapy alone group (table 1). The differences between each group were statistically significant, including between supervised exercise and stenting (P = 0.04).

Table 1. Primary Endpoint

For the secondary endpoint of change from baseline in claudication onset time, increases in the exercise and stenting groups were similar and significant compared with the medical therapy group (table 2).

Table 2. Claudication Onset Times

Another secondary endpoint, unstructured community walking measured by pedometer over 7 days, also increased in the exercise and stenting groups, but declined slightly in the medical therapy group.

Compared with the medical therapy group, walking impairment questionnaires revealed significant improvements in pain severity for stenting (P < 0.001) but not for exercise (P = 0.25). Walking distance improved significantly more in the stenting group than in the medical therapy group (P < 0.001) or exercise group (P = 0.03). The same pattern persisted for walking speed. Furthermore, stair climbing was similar and significantly improved in the stenting and exercise groups compared with medical therapy.

Michael S. Conte, MD, of the UCSF Medical Center (San Francisco, CA), noted that the data suggest optimal medical care has little clinical benefit. With regard to the better treadmill performance in the exercise group but better self-reported QOL for stenting, he said: “We lack understanding on the mechanisms of treatment benefit, and the optimal outcome measure for intermittent claudication trials that correlates with daily life.”

Session moderator Valentin Fuster, MD, of Mount Sinai Medical Center (New York, NY), questioned whether exercise could open existing collaterals (in which case they would not be persistent) or if it opened new collaterals (in which case they may be persistent).

According to Dr. Hirsch there is no evidence that growing collaterals occurs in this population. But, he said there are at least 50 studies in humans that clearly demonstrate the mechanism of benefit of exercise.

“Arteriolar function, vasomotor dilation to the muscles is improved by exercise,” Dr. Hirsch explained. “If you decondition your leg and then you exercise it, muscle blood flow improves… muscle is trained, becomes metabolically more efficient, the nerve-muscle unit becomes more efficient, and people walk better. This is truly a systematic improvement of the entire limb. The limb is not just an artery. It should be sustainable.”

Study Details

Baseline characteristics were well matched among the groups, except that prior stroke was more common in the exercise group. Mean age was 65 years.

Baseline treadmill walking time was similar between groups (5.3 minutes), as was time to claudication (1.7 minutes).

Related Stories:

• New PAD Recommendations Build Support for Endovascular Treatment
• PCI for PAD Grows as Surgery Declines: A Boon for Patients?