Supervised Exercise as Effective, Durable as Stenting in PAD Patients With Claudication
In PAD patients with claudication, supervised exercise and stenting both similarly improve walking performance and QoL for up to 18 months, according to a study published in the March 17, 2015, issue of the Journal of the American College of Cardiology. The benefit of exercise is maintained for a full year beyond the supervised training phase with use of a telephone-based counseling program.
Six-month results from the randomized CLEVER trial, presented at the American Heart Association Scientific Sessions in November 2011 and simultaneously published in Circulation, showed that supervised exercise provides the greatest improvement in treadmill walking performance compared with both stenting and optimal medical care, while stenting yields the best QoL.
For the trial, investigators led by Timothy P. Murphy, MD, of Rhode Island Hospital (Providence, RI), randomized 111 patients with aortoiliac artery PAD and moderate-to-severe claudication to optimal medical care alone (n = 22) or in addition to either supervised exercise (n = 43) or stenting (n = 46). Participants were enrolled at 29 centers in the United States and Canada between April 24, 2007, and January 11, 2011.
Supervised exercise consisted of treadmill walking during up to 78 scheduled 1-hour sessions, 3 days a week for 6 months, followed by a telephone-based maintenance program aimed at promoting exercise adherence for 12 more months. Optimal medical care included use of atherosclerosis risk factor management, cilostazol (Pletal; Otsuka America; Rockville, MD), and home exercise counseling.
Baseline characteristics of the 3 treatment arms were similar, although the exercise patients were more likely to have a history of stroke. The 79 patients who completed 18-month follow-up were similar to those who did not.
Compliance with the therapeutic assignment was high and crossovers were minimal. Initial revascularization was technically successful in all attempted cases, and only one patient was treated for restenosis between 6 and 18 months. In the supervised exercise group, 71% attended at least 70% of their schedule training sessions and 88% participated in the full home-based telephone support program. At 18 months, 91% of all participants were taking cilostazol, with no difference in compliance among the groups.
Exercise, Stenting Both Surpass Optimal Medical Care
Peak walking time improved least for medical care patients, more for stented patients, and most for the supervised exercise group. Although the gain was greater for both the stent and exercise groups compared with the optimal medical arm (P = .04 and P < .001, respectively), there was no difference between the stent and exercise groups (P = .16). For claudication onset time, the exercise group improved more than did the medical care group (P = .03), but no other comparisons achieved significance. Mean ankle-brachial indices were normalized, with differences favoring stenting over both medical care (P = .002) and supervised exercise (P < .001; table 1).
Per-protocol analyses yielded similar results, except that exercise no longer showed an advantage over optimal medical care.
There were no baseline differences in QoL among the treatment groups. At 18 months, improvements in the Walking Improvement Questionnaire and Peripheral Artery Questionnaire scales were superior for stenting and exercise compared with medical care. Stenting was favored over exercise only for the Peripheral Artery Questionnaire physical limitation (P = .04), QoL (P = .04), and summary (P = .04) scores.
According to the researchers, exercise stimulates a biological adaptive response, and “[t]he durability of the treatment effect… up to a year after termination of [supervised exercise] provides evidence that the benefits [of] treadmill walking are not solely due to a treadmill-specific training effect.”
Why Intervention Is Chosen Routinely
In an accompanying editorial, Piotr S. Sobieszczyk, MD, and Joshua A. Beckman, MD, both of Brigham and Women’s Hospital (Boston, MA), write that despite a paucity of clinical trials supporting the durability of stenting for this indication and existence of guidelines recommending supervised exercise as the initial treatment, “endovascular therapy has become, de facto, the only treatment in the management of patients with claudication due to aortoiliac arterial disease.”
They suggest several likely reasons for this, including:
- Stenting, when successful makes patients feel better quickly
- Treatment time for endovascular therapy is short
- Unlike stenting, exercise requires a substantial investment of time and effort by both patients and providers
- Only endovascular therapy is reimbursed by Medicare
- Until now, the benefits of a training program once it has ended have been unclear
“The lack of reimbursement for walking is particularly distressing, for it presumes that ‘1 size fits all,’” Drs. Sobieszczyk and Beckman say. “This is particularly irksome, because exercise has ancillary benefits, with reductions in blood pressure, improvements in the lipid profile, and better glucose control—all standard recommendations for patients with atherosclerosis.”
In addition, the editorial observes, intervention and exercise should not be pitted against each other because they have different mechanisms of action and outcomes. “Cilostazol, supervised exercise therapy with follow-up telephone monitoring, and endovascular revascularization are complementary, should be used as needed in appropriate patients, and applied until the patient is better,” Drs. Sobieszczyk and Beckman say.
Findings Should Help ‘Sell’ Exercise
“The rap on exercise has been that you can’t get people to keep doing it,” Thom W. Rooke, MD, of the Mayo Clinic (Rochester, MN), told TCTMD in a telephone interview. “So the fact that people continued to exercise to some extent or maintained the benefit from having exercised even if they stopped was quite surprising.”
Dr. Rooke agreed that some patients will likely benefit more from exercise and some from revascularization, but because it is unpredictable who will fall into each group, he suggested, “Why not exercise first, since there is no downside to it?”
“This study is exactly the kind of thing [practitioners] would like to have” when discussing treatment options with patients, Dr. Rooke said. “Now we can say, ‘We could put you through this invasive procedure, but the data show it’s not necessarily going to be any more effective than if you just walk more.’”
Physician Advocacy Key
Coauthor Alan T. Hirsch, MD, of the University of Minnesota Medical Center (Minneapolis, MN), disputed the shibboleth that patients “will always choose the quick, easy fix.”
Although circumstances may prompt some individuals to opt for an invasive procedure, the real issue is whether the exercise option is widely available, he said. And that depends on physician advocacy and leadership, he stressed, adding that while reimbursement would be welcome, simply blaming the government or insurers distracts attention from this responsibility.
Even from a biological perspective, revascularization is not the first treatment choice, Dr. Hirsch said, noting that blood flow in a large artery is not the primary physiologic determinant of muscle function and walking ability.
He acknowledged that up to one-fifth of claudicants have a comorbidity such as arthritis, chronic obstructive pulmonary disease, or angina that limits their ability to exercise. But, he noted, these conditions may also affect other treatment strategies. Moreover, tailored physical therapy can often address both claudication and the limiting condition.
Importantly, supervised exercise has been proven to be cost-effective relative to medical therapy, perhaps more so than stenting, Dr. Hirsch said, citing a recent health economic analysis of the CLEVER study. As for backup support to keep patients motivated, he noted that such programs are routinely offered to A-fib or heart failure patients.
CLEVER and other studies show that with supervised exercise “we now have a therapy that is effective, safe, and could be [implemented] anywhere within a month. It helps the individual, it helps society, and it lowers costs,” Dr. Hirsch concluded.
1. Murphy TP, Cutlip DE, Regensteiner JG, et al. Supervised exercise, stent revascularization, or medical therapy for claudication due to aortoiliac peripheral artery disease: the CLEVER study. J Am Coll Cardiol. 2015;65:999-1009.
2. Sobieszczyk PS, Beckman JA. Intervention or exercise? the answer is yes [editorial]! J Am Coll Cardiol. 2015;65:1010-1012.
Supervised Exercise as Effective, Durable as Stenting in PAD Patients With Claudication
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- The study was sponsored primarily by the National Heart, Lung, and Blood Institute and received financial support from Boston Scientific, Cordis/Johnson & Johnson, and ev3.
- Dr. Murphy reports receiving research grant support form Abbott Vascular, Cordis/Johnson & Johnson, and Otsuka Pharmaceuticals.
- Dr. Hirsch reports receiving research grants from Aastrom Biosciences, Abbott Vascular, AstraZeneca, and Viromed and serving as a consultant to Merck and Novartis.
- Dr. Beckman reports serving as a consultant to AstraZeneca, Bristol-Myers Squibb, Merck, and Novartis; receiving a research grant from Bristol-Myers Squibb; and serving on the board of directors of VIVA Physicians.
- Drs. Sobieszczyk and Rooke report no relevant conflicts of interest.