Lower extremity peripheral artery disease (PAD) is the third leading cause of atherosclerotic vascular morbidity after coronary heart disease and stroke.¹ It is estimated that over 200 million people worldwide² and 8.5 million Americans over the age of 40³ have PAD.

Intermittent claudication from PAD is known to affect approximately 4.5% of the general population at or over the age of 40⁴ and it is independently associated with an increased risk of all-cause and cardiovascular mortality^{5, 6} and marked reductions in quality of life.^{7, 8}

Unfortunately, few effective treatments exist for intermittent claudication.⁹ Cilostazol is the only effective medical therapy to improve symptoms but is not widely utilized.¹⁰ Pentoxifylline is the only other medication that has U.S. Food and Drug Administration approval for the treatment of PAD-related walking impairment,¹¹ but is no longer guideline-recommended due to lack of data supporting its efficacy.¹⁰

Supervised exercise therapy (SET) is an effective intervention to reduce lower extremity symptoms in patients with intermittent claudication from PAD. Due to data from several trials, including ones with long-term follow-up,^12-14 consensus guidelines recommend SET to improve functional status and quality of life, and to reduce leg symptoms.¹⁰

The guidelines also recommend SET prior to consideration of revascularization, as well as a key part of combination therapy in patients who undergo revascularization for refractory sytmptoms.¹⁰

The Endovascular Revascularization and Supervised Exercise (ERASE) study found that after one year of follow-up, combination therapy with endovascular revascularization followed by SET resulted in significantly greater improvement in walking distances and quality of life scores compared with SET only in patients with PAD and stable claudication for at least three months.¹⁵

Until 2017, the lack of reimbursement for this therapy greatly limited access and utilization.¹⁶ However, in 2017, the Centers for Medicare and Medicaid Services (CMS) "determined that the evidence [was] sufficient to cover SET for beneficiaries with intermittent claudication for the treatment of symptomatic PAD" (CPT code: 93668). Up to 36 sessions are covered over a 12-week period if all the components listed in Table 1 are met.

In addition, beneficiaries must have a face-to-face visit with the physician responsible for PAD treatment to obtain the referral to SET, and the beneficiary must receive information regarding cardiovascular disease and PAD risk factor reduction at this visit.

Graded treadmill-based exercise prescriptions are the foundation of SET. After a five-minute warm-up period, participants are asked to walk on the treadmill using provider- and patient-centered protocols until they have mild to moderate pain (3-4 of 5 on the claudication scale^{17, 18}).

They are then asked to stop, sit down and rest until the pain has completed resolved. Then they resume walking. The goal is to reach an exercise session of 50 minutes in duration (including rest periods), which allows for five-minute warm-up and cool-down periods to bring the total session duration to 60 minutes.

Progression of the intensity of the exercise prescription typically occurs between sessions, not during a session. Commonly utilized graded protocols in SET Programs are listed in Table 2.^19-22

In addition to graded exercise test-based metrics, functional evaluation can be done at intake and exit sessions with a six-minute walk test.^{23, 24} Symptom and quality of life assessments can be done via disease-specific questionnaires, such as the Walking Impairment Questionnaire (WIQ)²⁵ and the Peripheral Artery Questionnaire (PAQ),²⁶ and other validated metrics.

In addition to improving access to guideline-recommended care for patients with PAD and providing patient-centered care, the establishment and growth of a SET Program provide opportunities to build on intra- and inter-institutional collaboration between cardiovascular medicine, interventional cardiology and vascular surgery programs.

Benefits include direct revenue generation through a service offering, referrals to a center's vascular lab, vascular imaging center, cardiovascular medicine and vascular surgery clinics, and interventional and surgical programs, and opportunities for research.

Importantly, many centers already have the infrastructure needed to build a SET Program via their existing cardiac rehabilitation and/or physical therapy programs.^{22, 27}

After rolling out the Program on a small scale, it can grow quickly with referrals and charges that will allow for resource allocation requests. With increases in enrollment, research programs and quality improvement initiatives can be built within SET Programs.

An important contemporary consideration due to the COVID-19 pandemic is that home-based exercise regimens for intermittent claudication from PAD, while less effective than SET, may be reasonable options.

Many cardiac rehabilitation and physical therapy centers remain closed or have drastically limited the number of patients they serve. Studies have shown that home-based programs can improve walking endurance and physical activity in patients with PAD.²⁸

In summary, SET is a data-supported and guideline-recommend treatment for patients with intermittent claudication from PAD. It is our responsibility as a cardiovascular community to improve access to this important treatment, particularly now that it is a reimbursed service by CMS for Medicare beneficiaries, and by many private insurers.

Clinical Topics: Cardiovascular Care Team, COVID-19 Hub, Diabetes and Cardiometabolic Disease, Prevention, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Exercise

Keywords: ACC Publications, Cardiology Magazine, Intermittent Claudication, Peripheral Arterial Disease, Exercise Test, Walking, Cardiac Rehabilitation, Pentoxifylline, COVID-19, Quality of Life, Risk Factors, Centers for Medicare and Medicaid Services, U.S., Current Procedural Terminology, Medicare, Nurse Clinicians

< Back to Listings