CHICAGO – Home-based exercise for peripheral arterial disease–related walking limitations works at least as well as – and arguably better than – the supervised outpatient hospital clinic-based treadmill exercise programs of the type approved for coverage by the Centers for Medicare and Medicaid Services in 2017, Mary M. McDermott, MD, said at a symposium on vascular surgery sponsored by Northwestern University.
Dr. Mary M. McDermott
“The prevailing thinking is that supervised treadmill exercise is more effective than home-based exercise for PAD. And for the outcome of treadmill walking that is true. But for the outcome of 6-minute walking distance, which I would argue is more relevant to walking in daily life, home-based exercise programs appear to be better. Supervised treadmill exercise interventions preferentially improve treadmill walking performance, and that doesn’t translate as well to walking in daily life. Home-based exercise, where patients walk in a corridor or on the ground, is more relevant to the type of walking that they want to do,” explained Dr. McDermott, professor of medicine at the university as well as a leader in the field of research on exercise as a treatment for PAD.
However, she added a caveat regarding home-based exercise for symptomatic PAD: For it to be effective it must incorporate proven behavioral change techniques, including goal setting, monitoring progress, accountability to a coach, and face-to-face visits at least once per month.
“It seems you can’t just tell PAD patients to go home and walk because most of them won’t do it,” observed Dr. McDermott, who is a general internist and geriatrician.
Home-based exercise programs aren’t reimbursed by the CMS. But studies by Dr. McDermott and other investigators indicate that the results are more durable than for supervised treadmill exercise. For example, in the Group Oriented Arterial Leg Study (GOALS) – a 6-month group-mediated cognitive behavioral intervention in which PAD patients built up to walking at home for up to 50 minutes per session 5 days per week – 6-minute walking distance (6MWD) remained significantly better than in controls at follow-up after completion of the intervention. In fact, 6MWD actually increased further between 6 and 12 months in the home exercise group (J Am Heart Assoc. 2014 May 21;3(3):e000711. doi: 10.1161/JAHA.113.000711). Dr. McDermott was the lead author for this study.
In contrast, another study by Dr. McDermott now in press for the same journal found that the improvement in 6MWD achieved in PAD patients over the course of a 6-month supervised treadmill exercise program was not maintained during the next 6 months after completion of the intervention. Indeed, 6MWD showed a steady decline from its apex at the intervention’s conclusion, such that at the 12-month mark it was no longer significantly different from that of the control group, according to Dr. McDermott.
The Society for Vascular Surgery recommends a supervised exercise program as first-line therapy for PAD patients with intermittent claudication, with a Class I Level of Evidence A designation. Home-based exercise also gets a Class I recommendation, albeit with Level of Evidence B.
Dr. McDermott believes a home exercise program makes the most sense for PAD patients after their CMS benefit for a supervised clinic-based program has run out, or for patients – and there are a great many – who either can’t or don’t want to participate in a supervised program. She and others who’ve led randomized controlled trials of supervised exercise programs have found that close to 70% of eligible PAD patients decline to participate because of the inconvenience of going to the hospital outpatient facility at least three times per week or for other reasons.
“Also, it’s important to recognize that attendance can be a challenge, even when supervised exercise is covered by insurance. In our randomized trials, where we provide transportation, we still see only 65%-70% adherence to attendance,” she noted.
She stressed that it’s crucial for physicians and surgeons to educate their PAD patients about what to expect from an exercise program, be it supervised or home based.
“It’s not like revascularization, where they’re going to feel better in their walking immediately. It really takes a commitment. Four to six weeks is usually required before patients begin to experience a benefit, and I think it’s really important for patients to know that so they don’t get discouraged in the first couple of weeks,” Dr. McDermott said.
Turning to the key evidence-based behavioral change techniques shared by successful home-exercise programs for PAD, she noted that the GOALS trial intervention utilized weekly group sessions in which simple cognitive behavioral self-regulatory techniques were used to help patients set and stick to home-based walking goals. A similarly positive randomized controlled trial by investigators at the University of Oklahoma utilized once-monthly group meetings at the medical center (J Am Heart Assoc. 2014 Sep 18;3(5):e001107. doi: 10.1161/JAHA.114.001107).
In contrast, in the recent HONOR randomized clinical trial, where Dr. McDermott and her coinvestigators tested whether a home-based exercise intervention in which the active treatment group utilized a Fitbit wearable activity monitor and telephone coaching over the course of 9 months, the results proved disappointing. The intervention was no more effective than was usual care at improving 6MWD (JAMA. 2018 Apr 24;319(16):1665-76).
“One of the things I learned from doing this trial is that for a home-based exercise intervention in PAD to be successful, it’s not easy and there really needs to be some ongoing contact with a coach or nurse or a staff member that the patient feels accountable to. A wearable device is not a durably effective motivator for PAD patients. I think the reason this trial didn’t work so well is that most of it was by telephone and it was easy for patients to avoid our calls if they weren’t walking. Patients were initially really enthusiastic about the Fitbit, but we found that over time they stopped wearing it,” she said.
Dr. McDermott heartily endorses the Society for Vascular Surgery’s Class I recommendation that all PAD patients with intermittent claudication should exercise regularly, including those who’ve undergone revascularization procedures. Numerous clinical trials have demonstrated additive clinical benefits for opening the peripheral artery and strengthening skeletal muscles.
Uptake of supervised exercise programs for symptomatic PAD since the CMS coverage decision is quite variable regionally. Integrating new programs into existing cardiac rehabilitation facilities is a natural fit because staff members are very familiar with structured treadmill exercises already on site, but some freestanding programs are run by vascular surgery groups or cardiologists.
“I think part of the reason it hasn’t been taken up faster is that the reimbursement is such that you’re not going to make money on it,” Dr. McDermott said.
Asked if all patients with PAD should undergo an exercise treadmill test before embarking on an exercise program, Dr. McDermott replied, “I’m part of a writing group for the American Heart Association on how to implement these new guidelines. We’re not formally recommending a stress test. Some cardiologists on the panel suggested that it should be individualized based on patient history and symptoms. If they’re having symptoms of chest pain or they have a significant cardiac history, go ahead with a stress test. I don’t think it’s going to be recommended as a routine practice, but it’s safest to get a stress test.”
She reported having no financial conflicts regarding her presentation.