Peripheral Artery Disease Supervised Exercise Therapy: Solvitur Ambulando

Exercise plays a fundamental role in the treatment of peripheral artery disease (PAD) based on a wealth of data from clinical trials and meta-analyses dating back to the 1960s. The concept of “exercise as medicine” is appealing, legitimate, and proven.¹

Thanks in part to the heroic efforts of my vascular medicine colleagues, in 2017, the Centers for Medicare & Medicaid Services (CMS) issued a key National Coverage Determination for supervised exercise therapy (SET) for symptomatic PAD, which represents a potential sea change in the paradigm of PAD care.

We celebrated this CMS event, both at a national level in the vascular medicine community and at a local level in our own Clinical Exercise Center at Johns Hopkins. Then we all looked at each other and said, “Now what?”. At that point, we had experience with offering PAD SET on a small scale for self-pay patients or those with other insurance coverage. We had a protocol from our prior participation as a site for the CLEVER (Claudication: Exercise Vs. Endoluminal Revascularization) trial.² This protocol seemed like a good starting place since the CLEVER trial demonstrated that SET improved treadmill walking performance more than endovascular revascularization for patients with aorto-iliac disease. However, as outlined in the prior AHA Scientific Statement on optimal exercise programs for patients with PAD, studies have varied significantly with respect to the intensity, duration, and frequency of exercise.³ Given the variety of approaches, many of us had unanswered questions and we wanted to be certain that we were all on the same page.

Flurries of emails were exchanged across the country about how to proceed to ensure that we were capturing the best data, meeting the CMS requirements, and best serving our patients. Which test should we use to measure exercise performance at baseline and at the end of the program? Does everyone need a stress test first? What outcome measures should be recorded at each visit? What needs to be added or subtracted from the cardiac rehabilitation protocol? What is the metric of program success? How should we assess quality of life? What questionnaires should we use and do we need to pay for them? How should all the data be captured in the electronic medical record? Without a doubt, clinical implementation of SET is quite different from a research study. Time is much more limited, and the reimbursement is exceedingly low for the time invested. We need to be efficient, selective, and effective.

With these questions and challenges as a backdrop, the AHA Science Advisory "Implementation of Supervised Exercise Therapy for Patients with Symptomatic Peripheral Artery Disease" is a welcome addition to the field, providing a succinct and practical approach to SET. While many cardiac rehabilitation programs have expanded to PAD SET, the method and requirements differ. This guide provides much-needed guidance. The prior AHA Scientific Statement3 provides the “WHY” and the new document provides the indispensable “HOW”.

With this AHA Science Advisory, Treat-Jacobson et al also provide excellent recommendations extending beyond the treadmill. Patient education plays a vital role in PAD care. While the treadmill is clearly the preferred primary training modality, the guidance here on incorporating non-treadmill modalities (such as upper body ergometry) is also particularly helpful. The recumbent total-body stepping (the NuStep) seems especially popular among my older patients. Finally, the importance of the transition to a long-term plan for community- or home-based exercise cannot be overemphasized. The 12 weeks of SET is just a snapshot in time, but we need to ensure that patients maintain the exercise prescription afterwards.

The authors have skillfully distilled vast amounts of data, using extensive clinical and research experience to come up with the best practices. Now that we are armed with this helpful guide, going forward it is our duty to capture data. Using the process outlined herein, we can gather real-world experience and thus continue to advance the field.

Of note, this statement does not mandate or advocate for one specific outcome measure or a particular questionnaire. PAD SET needs to be individualized for the local program itself (based on available resources and expertise) and for the patient, which is the “art” in exercise training. At the same time, we need to measure it and report what works well.

Literally millions of patients could potentially benefit from PAD SET but significant barriers remain. PAD SET requires an investment of time, money, and motivation. Problems with access, adherence, and underutilization persist. Fortunately, this statement virtually eliminates the issue of “How do we do it?”. We can now move forward with confidence. As the Greek philosopher Diogenes said in the 4th century B.C., “Solvitur ambulando” - “It is solved by walking.”