Exercise therapy for symptomatic peripheral artery disease following lower-extremity revascularization in two large healthcare systems

The 2016 intersociety peripheral artery disease (PAD) guidelines recommended structured exercise therapy for all patients with claudication—regardless of lower-extremity revascularization (LER) status—to improve walking performance, functional status, and quality of life. ¹ In the updated 2024 US PAD guidelines, supervised exercise therapy (SET) is now a Class 1 indication in patients who have undergone LER for chronic, symptomatic PAD. ² Historically, there has been under-utilization of this effective management strategy in all patients with symptomatic PAD (regardless of LER history) due to barriers at the system, provider, and patient levels. ³ This is unfortunate, as early LER for claudication is associated with higher rates of repeat LER and progression to chronic limb-threatening ischemia (CLTI). ⁴ Insurance coverage for SET has been an important barrier to implementation, but in 2017, the Center for Medicare & Medicaid Services (CMS) announced initiation of SET coverage for patients with symptomatic PAD. ⁵ This coverage partially reimburses SET three times weekly, for up to 12 weeks. ⁴ Despite this coverage change, there has been evidence that SET utilization remains low in the United States. ⁶ The purpose of this research was to evaluate real-world SET referral and discussion of home-based exercise at two large healthcare systems in Colorado.

The electronic medical records (EMRs) of patients who underwent surgical, endovascular, or hybrid LER from July 2016 to July 2021 for symptomatic PAD at Denver Health (Colorado’s safety-net healthcare system) and the University of Colorado healthcare systems were reviewed for documentation of provider–patient discussion of home-based exercise therapy or SET referral. Patients were identified using procedure and/or operating room schedules using the scheduling record on each of the institution’s EMR systems. Home-based exercise was included to improve the sensitivity to capture recommendations about exercise after LER, including during the COVID-19 pandemic. The protocol was evaluated and deemed exempt from review by the Colorado Multiple Institutional Review Board.

Of the 1103 patients included, the median age was 67 ± 7 years, and the cohort included 37% female patients, 19% Black patients, 21% Latino patients, and 86% local residents. A diagnosis of myocardial infarction and heart failure hospitalization were documented in 17% and 13% of the patient records, respectively. Documentation of provider–patient discussion of home-based exercise therapy occurred in 10 patients (0.9% of the cohort), and 24 (2.2%) of the patients were referred for SET (Figure 1). A total of 1069 (96.9%) patients had neither SET referral nor home-based exercise therapy documentation. For 13 (1.2%) of the patients included, discussion and referral could not be determined. SET referral rates did not change after CMS coverage started in 2017 (Figure 1).

Figure 1.

Number of patients who underwent lower-extremity revascularization (LER), by exercise referral, at (A) University of Colorado and (B) Denver Health.

Despite the recommendation for SET in patients who have undergone LER for symptomatic PAD and CMS coverage starting in 2017, referral for SET remained low in both a large academic medical center and an urban safety-net hospital system between 2016 and 2021. Importantly, CMS does not cover the full cost of SET, and recent qualitative research revealed that the $11 copay required for each session was a major obstacle for many patients. ⁷ Other patient barriers in this study included the time commitment, inconvenience, and lack of interest in walking on a treadmill. ⁷ Other studies have demonstrated that lack of motivation, ⁷ other comorbid conditions, ⁸ higher body mass index, ⁹ and lower household income ⁹ are reasons patients either did not participate in or did not complete the 12 weeks of SET.

Though there are many barriers at the patient level, this review of two large US healthcare systems demonstrated poor implementation at the provider level, consistent with previous research findings.^4,10 The issue of poor referral rates has been ongoing for decades now, so it is worth emphasizing that improved referral rates are possible, as demonstrated by a 90% referral rate for patients with symptomatic PAD in the Netherlands. ¹⁰ An important factor that has contributed to more successful implementation in the Netherlands is greater availability of SET facilities compared to other European countries. ¹¹ Barriers specific to US providers include lack of SET center availability and lack of awareness regarding CMS coverage. ² In addition to improved accessibility and provider awareness about coverage, the development of performance and quality measures for SET programs (akin to cardiac and pulmonary rehabilitation programs) and the development of SET registries are potential ways to improve SET utilization. Achieving these goals will require collaboration by vascular societies at the national level and by vascular providers at the grassroots level.

There are limitations to this retrospective study. First, this review included only two medical systems in Colorado, and were based on provider documentation, so it is possible that providers recommended home-based exercise with more patients. Insurance coverage, PAD severity, and reasons referrals were not placed (e.g., transportation issues) were not captured. The timeframe of review included the COVID-19 pandemic, during which time SET referral rates would have been lower.

In conclusion, our real-world findings demonstrate the dire reality of poor SET referral in the US. For the health and well-being of our patients with symptomatic PAD, the vascular community must continue to drive research and implementation efforts to improve utilization of this effective management strategy.