Implementation of Supervised Exercise Therapy for Patients With Symptomatic Peripheral Artery Disease: A Science Advisory From the American Heart Association

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Exercise Therapy for Peripheral Artery Disease

PURPOSE OF REVIEW

To summarize evidence regarding exercise treatments for lower extremity peripheral artery disease (PAD).

RECENT FINDINGS

Supervised walking exercise is recommended by practice guidelines for PAD. Supervised treadmill exercise improves treadmill walking distance by approximately 180 m and 6-min walk distance by 30-35 m, compared to control. The Centers for Medicaid and Medicare Services covers 12 weeks of supervised exercise, but most people with PAD do not participate. Home-based walking exercise may be more convenient and accessible than supervised exercise. In randomized clinical trials, home-based walking exercise interventions incorporating behavioral methods, such as accountability to a coach, goal-setting, and self-monitoring, improved 6-min walk distance by 40-54 m, compared to control. Arm and leg ergometry also improved walking endurance for people with PAD, but efficacy compared to walking exercise remains unclear. Walking exercise is first-line therapy for PAD-related walking impairment and can be effective in either a supervised or a structured home-based setting.

Short-duration aerobic high-intensity intervals versus moderate exercise training intensity in patients with peripheral artery disease: study protocol for a randomised controlled trial (the Angiof-HIIT Study)

INTRODUCTION

Supervised exercise training is among the first-line therapies for patients with peripheral artery disease (PAD). Current recommendations for exercise include guidance focusing on claudication pain, programme and session duration, and frequency. However, no guidance is offered regarding exercise training intensity. This study aims to compare the effects of 12-week-long supervised walking exercise training (high-intensity interval training (HIIT) vs moderate-intensity exercise (MOD)) in patients with chronic symptomatic PAD.

METHODS AND ANALYSIS

This study is a monocentric, interventional, non-blinded randomised controlled trial. 60 patients (30 in each group) will be randomly allocated (by using the random permuted blocks) to 12 weeks (three times a week) of HIIT or MOD. For HIIT, exercise sessions will consist of alternating brief high-intensity (≥85% of the peak heart rate (HRpeak)) periods (≤60 s) of work with periods of passive rest. Patients will be asked to complete 1 and then 2 sets of 5-7 (progressing to 10-15×60 s) walking intervals. For the MOD group, exercise training sessions will consist of an alternation of periods of work performed at moderate intensity (≤76% HRpeak) and periods of passive rest. Interventions will be matched by training load. The primary outcome will be the maximal walking distance. Secondary outcomes will include functional performance, functional capacity, heath-related quality of life, self-perceived walking abilities, physical activity and haemodynamic parameters.

ETHICS AND DISSEMINATION

The Angiof-HIIT Study was approved by the Human Research Ethics Committee of the Canton de Vaud (study number: 2022-01752). Written consent is mandatory prior to enrolment and randomisation. The results will be disseminated via national and international scientific meetings, scientific peer-reviewed journals and social media.

TRIAL REGISTRATION NUMBER

NCT05612945.

Exercise therapy for chronic symptomatic peripheral artery disease

All guidelines worldwide strongly recommend exercise as a pillar of the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended for clinicians to promote and assist for the set-up of comprehensive exercise programmes to best advice in patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are narratively described based on the current best evidence. The document ends by highlighting disparities in access to supervised exercise programmes across Europe and the series of gaps for evidence requiring further research.

Functional Status in Peripheral Arterial Disease: Rehabilitated Versus Nonrehabilitated

BACKGROUND

To analyze patient perception of functional status related to activity and participation of rehabilitated and nonrehabilitated individuals with peripheral arterial disease.

METHODS

Cross-sectional study assessing the activity and participation domain using the Human Activity Profile (HAP) questionnaire and the Participation Scale, respectively. Groups were compared using Chi-squared test and unpaired t-test.

RESULTS

A total of 87 individuals (36 rehabilitated) with 65.28 ± 8.29 years (66.7% male) were included. HAP classified 58.6% of individuals with weak or inactive physical activity level, and approximately half of the sample did not have participation restriction. HAP scores and Participation Scale (locomotion inside and outside home) were lower in nonrehabilitated than in rehabilitated individuals.

CONCLUSIONS

Individuals with peripheral arterial disease presented little participation restriction and a great activity limitation, the last one being more evident among nonrehabilitated.

Socioeconomic factors predict successful supervised exercise therapy completion

OBJECTIVE

Supervised exercise therapy (SET) for patients with intermittent claudication (IC) can lower the risk of progression to chronic limb-threatening ischemia and amputation, while preserving and restoring functional status. Despite supporting evidence, it remains underutilized, and among those who initiate programs, attrition rates are extremely high. We hypothesize that socioeconomic factors may represent significant barriers to SET completion.

METHODS

Patients with IC referred to SET at a multi-hospital, single-institution health care system (2018-2022) from a prospectively maintained database were retrospectively analyzed. Our primary endpoint was SET program completion and graduation, defined as completion of 36 sessions. Our secondary endpoints were vascular intervention within 1 year of referral and change in ankle-brachial index (ABI). Baseline demographics were assessed using standard statistical methods. Predictors of SET graduation were analyzed using multivariable logistic regression generating adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Change in ABI was analyzed using t-test between subgroups. Reasons for attrition were tabulated. Patient Health Questionnaire-9 (PHQ-9), metabolic equivalent level, Vascular QOL, Duke Activity Status, and ABI were analyzed using paired t-tests across the entire cohort.

RESULTS

Fifty-two patients met inclusion criteria: mean age 67.85 ± 10.69 years, 19 females (36.54%), mean baseline ABI of 0.77 ± 0.16. The co-pays for 100% of patients were fully covered by primary and secondary insurance plans. Twenty-one patients (40.38%) completed SET. On multivariable analysis, residence in a ZIP code with median household income <$47,000 (aOR, 0.10; 95% CI, 0.01-0.76; P = .03) and higher body mass index (aOR, 0.81; 95% CI, 0.67-0.99; P = .04) were significant barriers to SET graduation. There were no differences in ABI change or vascular intervention within 1 year between graduates and non-graduates. Non-graduates reported transportation challenges (25.00%), lack of motivation (20.83%), and illness/functional limitation (20.83%) as primary reasons for SET attrition. Metabolic Equivalent Level (P ≤ .01) and Duke Activity Status scores (P = .04) were significantly greater after participating in a SET program.

CONCLUSIONS

Although SET participation improves lower extremity and functionality outcomes, only 40% of referred patients completed therapy in our cohort. Our findings suggest that both socioeconomic and functional factors influence the odds of completing SET programs, indicating a need for holistic pre-referral assessment to facilitate enhanced program accessibility for these populations.

Exercise therapy for chronic symptomatic peripheral artery disease

All guidelines worldwide strongly recommend exercise as a pillar in the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended to promote and assist the set up of comprehensive exercise programmes and best advice for patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are described based on the current best evidence. The document ends by highlighting supervised exercise programme access disparities across Europe and the evidence gaps requiring further research.

Uptake and outcomes of supervised exercise therapy for peripheral artery disease: The importance of vascular medicine specialists at a large midwestern health care system during the first 5 years of CMS reimbursement

BACKGROUND

Supervised exercise therapy (SET) is the cornerstone of medical therapy for symptomatic peripheral artery disease (PAD). Despite the efficacy of SET, initial reports following the 2017 Centers for Medicare and Medicaid Services (CMS) reimbursement decision indicate low SET uptake, referral, and completion. Vascular medicine specialists are key to the success of such programs. We examined rates of SET referral, completion, and outcomes in a health system with a robust SET program during the first 5 years of CMS reimbursement.

METHODS

A retrospective chart review of patients with PAD referred to SET between October 1, 2017 and December 31, 2022 was conducted. Patient demographic and medical characteristics, SET indication, referring provider specialty, SET participation (e.g., exercise modality, number of sessions, treadmill prescription), and outcomes were abstracted. Descriptive statistics, t-tests, and multiple linear regression were used to examine the sample, evaluate outcomes, and explore outcomes by relevant covariates (i.e., age, sex, referring provider specialty).

RESULTS

Of 5320 patients with PAD, N = 773 were referred to SET; N = 415 enrolled and were included in the present study. Vascular medicine and vascular surgery specialists were the two primary sources of referrals (30.6% and 51.6%, respectively). A total of 207 patients (49.9%) completed SET. Statistically significant and clinically meaningful improvements were observed in all outcomes.

CONCLUSION

SET referral and completion rates are low in the 5 years following CMS reimbursement, despite the advocacy of vascular medicine specialists. SET is effective in improving patient functional capacity and quality of life. Additional efforts are needed to increase both SET availability and referrals as part of comprehensive treatment of PAD.

A 6-minute Limb Function Assessment for Therapeutic Testing in Experimental Peripheral Artery Disease Models

Background

The translation of promising therapies from pre-clinical models of hindlimb ischemia (HLI) to patients with peripheral artery disease (PAD) has been inadequate. While this failure is multifactorial, primary outcome measures in preclinical HLI models and clinical trials involving patients with PAD are not aligned well. For example, laser Doppler perfusion recovery measured under resting conditions is the most used outcome in HLI studies, whereas clinical trials involving patients with PAD primarily assess walking performance. Here, we sought to develop a 6-min limb function test for preclinical HLI models that assess muscular performance and hemodynamics congruently.

Methods

We developed an in situ 6-min limb function test that involves repeated isotonic (shortening) contractions performed against a submaximal load. Continuous measurement of muscle blood flow was performed using laser Doppler flowmetry. Quantification of muscle power, work, and perfusion are obtained across the test. To assess the efficacy of this test, we performed HLI via femoral artery ligation on several mouse strains: C57BL6J, BALBc/J, and MCK-PGC1α (muscle-specific overexpression of PGC1α). Additional experiments were performed using an exercise intervention (voluntary wheel running) following HLI.

Results

The 6-min limb function test was successful at detecting differences in limb function of C57BL6/J and BALBc/J mice subjected to HLI with effect sizes superior to laser Doppler perfusion recovery. C57BL6/J mice randomized to exercise therapy following HLI had smaller decline in muscle power, greater hyperemia, and performed more work across the 6-min limb function test compared to non-exercise controls with HLI. Mice with muscle-specific overexpression of PGC1α had no differences in perfusion recovery in resting conditions, but exhibited greater capillary density, increased muscle mass and absolute force levels, and performed more work across the 6-min limb function test compared to their wildtype littermates without the transgene.

Conclusion

These results demonstrate the efficacy of the 6-min limb function test to detect differences in the response to HLI across several interventions including where traditional perfusion recovery, capillary density, and muscle strength measures were unable to detect therapeutic differences.

Illness beliefs relation to physical activity and quality of life in patients with peripheral arterial disease

Intermittent claudication is the most common symptom of Peripheral Arterial Disease (PAD) and is associated with decreased quality of life (QoL) due to walking impairment. The level of threat attributed to the disease affects QoL and physical activity. This study explores beliefs and illness drawings, and their relationship with quality of life and physical activity in patients undergoing conservative treatment for PAD. A cross-sectional study was carried out including 119 patients with PAD and Intermittent Claudication, in which patients were asked to freely draw their disease and 33 agreed to participate. The profile of beliefs about PAD is characterized by a low level of threat. Belief in the emotional impact of the disease, representations about the consequences and concern about the disease were associated with worse quality of life; the belief of having a high personal control over the disease was associated with more physical activity. The analysis of the disease drawings revealed three categories: extension of the disease (category 1), location and representations of the disease (category 2), and level of detail and complexity of the drawings (category 3). Greater disease extent was associated with more disease symptoms (IPQ 6) (rs = 0.399, p = .021). It is necessary to address beliefs and representations about the disease in consultations with patients with PAD. Patient drawings are a useful, practical, and free tool that does not require a lot of time and can facilitate the approach of health professionals to patient training and education.

Exercise Therapy for Chronic Symptomatic Peripheral Artery Disease: A Clinical Consensus Document of the European Society of Cardiology Working Group on Aorta and Peripheral Vascular Diseases in Collaboration With the European Society of Vascular Medicine and the European Society for Vascular Surgery

All guidelines worldwide strongly recommend exercise as a pillar in the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended to promote and assist the set up of comprehensive exercise programmes and best advice for patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are described based on the current best evidence. The document ends by highlighting supervised exercise programme access disparities across Europe and the evidence gaps requiring further research.

Mobile health technologies to improve walking distance in people with intermittent claudication

BACKGROUND

Peripheral arterial disease (PAD) is the obstruction or narrowing of the large arteries of the lower limbs, which can result in impaired oxygen supply to the muscle and other tissues during exercise, or even at rest in more severe cases. PAD is classified into five categories (Fontaine classification). It may be asymptomatic or various levels of claudication pain may be present; at a later stage, there may be ulceration or gangrene of the limb, with amputation occasionally being required. About 20% of people with PAD suffer from intermittent claudication (IC), which is muscular discomfort in the lower extremities induced by exertion and relieved by rest within 10 minutes; IC causes restriction of movement in daily life. Treatment for people with IC involves addressing lifestyle risk factors. Exercise is an important part of treatment, but supervised exercise programmes for individuals with IC have low engagement levels and high attrition rates. The use of mobile technologies has been suggested as a new way to engage people with IC in walking exercise interventions. The novelty of the intervention, low cost for the user, automation, and ease of access are some of the advantages mobile health (mhealth) technologies provide that give them the potential to be effective in boosting physical activity in adults.

OBJECTIVES

To assess the benefits and harms of mobile health (mhealth) technologies to improve walking distance in people with intermittent claudication.

SEARCH METHODS

The Cochrane Vascular Information Specialist conducted systematic searches of the Cochrane Vascular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and CINAHL, and also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov. The most recent searches were carried out on 19 December 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in people aged 18 years or over with symptomatic PAD and a clinical diagnosis of IC. We included RCTs comparing mhealth interventions to improve walking distance versus usual care (no intervention or non-exercise advice), exercise advice, or supervised exercise programmes. We excluded people with chronic limb-threatening ischaemia (Fontaine III and IV).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were change in absolute walking distance from baseline, change in claudication distance from baseline, amputation-free survival, revascularisation-free survival. Our secondary outcomes were major adverse cardiovascular events, major adverse limb events, above-ankle amputation, quality of life, and adverse events. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included four RCTs involving a total of 614 participants with a clinical diagnosis of IC. The duration of intervention of the four included RCTs ranged from 3 to 12 months. Participants were randomised to either mhealth or control (usual care or supervised exercise programme). All four studies had an unclear or high risk of bias in one or several domains. The most prevalent risk of bias was in the area of performance bias, which was rated high risk as it is not possible to blind participants and personnel in this type of trial. Based on GRADE criteria, we downgraded the certainty of the evidence to low, due to concerns about risk of bias, imprecision, and clinical inconsistency. Comparing mhealth with usual care, there was no clear evidence of an effect on absolute walking distance (mean difference 9.99 metres, 95% confidence interval (CI) -27.96 to 47.93; 2 studies, 503 participants; low-certainty evidence). None of the included studies reported on change in claudication walking distance, amputation-free survival, or revascularisation-free survival. Only one study reported on major adverse cardiovascular events (MACE) and found no clear difference between groups (risk ratio 1.37, 95% CI 0.07 to 28.17; 1 study, 305 participants; low-certainty evidence). None of the included studies reported on major adverse limb events (MALE) or above-ankle amputations.

AUTHORS' CONCLUSIONS

Mobile health technologies can be used to provide lifestyle interventions for people with chronic conditions, such as IC. We identified a limited number of studies that met our inclusion criteria. We found no clear difference between mhealth and usual care in improving absolute walking distance in people with IC; however, we judged the evidence to be low certainty. Larger, well-designed RCTs are needed to provide adequate statistical power to reliably evaluate the effects of mhealth technologies on walking distance in people with IC.

Exercise Training for Patients With Peripheral Arterial Occlusive Disease

BACKGROUND

One-third of all persons with peripheral arterial occlusive disease (PAOD) suffer from intermittent claudication. Exercise training under appropriate supervision is recommended in the pertinent guidelines, but physicians order it too rarely, and so-called vascular exercise groups are not available everywhere. This situation needs improvement in view of the impor - tance of walking ability and cardiorespiratory fitness for patients' quality of life and long-term disease outcome.

METHODS

We review the scientific evidence on exercise training and on ways to lower barriers to the ordering of exercise training and to patient participation, on the basis of pertinent articles retrieved by a search of PubMed and in specialized sports science journals.

RESULTS

10 meta-analyses, 12 randomized controlled trials (RCTs), and 7 cohort studies were considered for this review. Largescale cohort studies have shown that exercise is associated with a lower risk of death (relative risk 0.65-0.78 after 12 months of exercise training, compared to an inactive lifestyle). Exercise training also improves the maximal walking distance by a mean of 136 m (training at home) or 180-310 m (supervised training). An additional improvement by a mean of 282 m can be expected from a combination of exercise training and endovascular revascularization. Further behavior-modifying interventions, such as goal-setting, planning, and feedback, increase both the maximum walking distance and the weekly duration of exercise.

CONCLUSION

Exercise improves walking ability and lowers mortality. To attract patients with intermittent claudication to exercise training, a broad assortment of analog, digital and telemetric tools and a dense network of vascular exercise groups should be made available, along with regular contact between physicians and patients.

Low-intensity resistance exercise with blood flow restriction for patients with claudication: A randomized controlled feasibility trial

BACKGROUND

Claudication is a common and debilitating symptom of peripheral artery disease, resulting in poor exercise performance and quality of life (QoL). Supervised exercise programs are an effective rehabilitation for patients with claudication, but they are poorly adhered to, in part due to the high pain and effort associated with walking, aerobic, and resistance exercise. Low-intensity resistance exercise with blood flow restriction (BFR) represents an alternative exercise method for individuals who are intolerant to high-intensity protocols. The aim of this study was to evaluate the feasibility of a supervised BFR program in patients with claudication.

METHODS

Thirty patients with stable claudication completed an 8-week supervised exercise program and were randomized to either BFR (n = 15) or a control of matched exercise without BFR (control; n = 15). Feasibility, safety, and efficacy were assessed.

RESULTS

All success criteria of the feasibility trial were met. Exercise adherence was high (BFR = 78.3%, control = 83.8%), loss to follow up was 10%, and there were no adverse events. Clinical improvement in walking was achieved in 86% of patients in the BFR group but in only 46% of patients in the control group. Time to claudication pain during walking increased by 35% for BFR but was unchanged for the control. QoL for the BFR group showed improved mobility, ability to do usual activities, pain, depression, and overall health at follow up.

CONCLUSION

A supervised blood flow restriction program is feasible in patients with claudication and has the potential to increase exercise performance, reduce pain, and improve QoL. (Clinicaltrials.gov Identifier: NCT04890275).

Coronary vascular dysfunction is associated with increased risk of death in patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) and coronary vascular dysfunction are common in patients with cardiometabolic disease. Neither the prevalence of coronary vascular dysfunction among patients with PAD nor the prognostic impact with these two conditions present together has been well studied.

METHODS

Consecutive patients who underwent PET MPI were analyzed for presence of coronary vascular dysfunction [myocardial blood flow reserve (MBFR) < 2]. Cox regression was used to examine the association of reduced MBFR with mortality in patients with PAD, as well as the association of comorbid MBFR < 2 and PAD with all-cause death.

RESULTS

Among 13,940 patients, 1936 (14%) had PAD, 7782 (56%) had MBFR < 2 and 1346 (10%) had both PAD and MBFR < 2. Reduced MBFR was very common (69.5%) and was associated with increased risk of all-cause death (HR 1.69, 95%CI 1.32, 2.16, p < 0.01) in patients with PAD. Patients with both PAD and MBFR < 2, and those with either PAD or reduced MBFR had increased risk of death compared to those with neither condition: PAD + MBFR < 2 [(HR 95%CI), 2.30; 1.97-2.68], PAD + MBFR ≥ 2 (1.37; (1.08-1.72), PAD - MBFR < 2 (1.98; 1.75-2.25), p < 0.001 for all).

CONCLUSION

Coronary vascular dysfunction was common in patients with PAD and was associated with increased risk of death.

Effects of Long-Term Home Exercise in Participants With Peripheral Artery Disease

Background This randomized controlled trial compared long-term changes in peak walking time (PWT) and exercise time-to-minimum calf muscle oxygen saturation (StO2) in symptomatic participants with peripheral artery disease following a long-term home exercise program (HEP), a short-term supervised exercise therapy (SET) program that transitioned to a long-term HEP (SET/HEP), and a control intervention. Methods and Results For the first 3 months, HEP and SET/HEP groups performed intermittent walking to mild-to-moderate claudication pain, whereas the control group performed light resistance training. For the subsequent 15 months, the HEP group continued their exercise program, the SET/HEP group transitioned from SET to the HEP program, and the control group transitioned to only receive walking advice. PWT increased significantly from baseline to month 18 in the HEP group (408±279 meters to 814±393 meters, P<0.001) and in the SET/HEP group (457±288 meters to 818±313 meters, P<0.001). Exercise time-to-minimum calf muscle StO2 increased significantly from baseline to month 18 in the HEP group (238±241 seconds to 497±485 seconds, P<0.05) and in the SET/HEP group (296±289 seconds to 620±450 seconds, P<0.001). These changes in PWT and exercise time-to-minimum calf muscle StO2 were greater than in the control group (P<0.001 and P<0.01, respectively). Additionally, the change in exercise time-to-minimum calf muscle StO2 was correlated with the change in PWT in both exercise groups combined (r=0.601, P=0.0015). Conclusions Long-term HEP and SET/HEP were efficacious in improving PWT and exercise time-to-minimum calf muscle StO2 in symptomatic participants with peripheral artery disease, and these changes were correlated with each other. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00618670.

Six-month effects of supervised exercise on walking ability and health-related factors in peripheral arterial disease: a pilot study

BACKGROUND

In peripheral arterial disease (PAD) patients with intermittent claudication (IC), the combination of aerobic and resistance exercises could counteract muscle loss and attenuate disease progression. This study analyzed the effects of six months of a combined exercise program on walking ability, lower limb body composition, cardiovascular risk factors, and Ankle-Brachial Index (ABI).

METHODS

Twenty-three patients (age 63.2±1.5 years and ABI 0.58±0.07) with PAD and IC were allocated to a control group (CG) or a supervised exercise group (SUP). Ten patients underwent six months of treadmill walking combined with resistance exercises, three times a week. The CG (N.=13) received a recommendation for walking. All patients were measured at baseline (M0), after three months (M3), and six months (M6).

RESULTS

During constant treadmill protocol, the claudication onset time/distance (COT/COD), absolute claudication time/distance (ACT/ACD), and number of pauses of overall patients significantly improved at M3 and M6. Between groups were found significant differences in COT and COD at M6 (P=0.005 and P=0.007, respectively); and in ACT and ACD at M3 (P=0.003 for both) and at M6 (P=0.005 and P=0.005, respectively), with major improvements in the SUP. Over the six months, a significant group effect was found in fat-free mass (P=0.041) and predicted muscle mass (P=0.039) of the lower ABI leg, with greater improvements in the SUP.

CONCLUSIONS

A supervised exercise program that combines aerobic and resistance training improves PAD symptoms and has additional benefits for patients. Patients in the program showed improvements in walking ability, lower-limb body composition, perceived exertion, and heart rate during treadmill walking.

Clinical Effectiveness of a Supervised Exercise Therapy Program for Treatment of Peripheral Artery Disease: A Translational Study

PURPOSE

National guidelines for the treatment and management of symptomatic peripheral artery disease (PAD) recommend supervised exercise therapy (SET) as a first line of therapy. However, it is unknown how these expert opinion-based SET guidelines work in clinical practice as SET programs become established following the 2017 Centers for Medicare & Medicaid Services coverage announcement. The purpose of this prospective, nonrandomized translational study was to evaluate the clinical effectiveness of a SET program and specifically walking exercise modalities that did not incorporate a treadmill (TM).

METHODS

Participants enrolled in a 12-wk SET program housed in four rural Midwest cardiac rehabilitation settings and were prescribed an exercise program by an exercise physiologist or nurse based on current SET guidelines. Groups included TM walking, total body recumbent stepping (TBRS), TM walking + TBRS, and multimodal. Pre- and post-tests of walking capacity, physical function, and quality of life were administered.

RESULTS

The sample (n = 93) was all White, with 55% female representation, age of 73.7 ± 9.0 yr, and mild-moderate PAD (ankle-brachial index = 0.71 ± 0.19). Collectively, SET significantly improved the 6-min walk test (32.1 ± 6.6 m; P < .01). Within-group changes in the 6-min walk test were seen for all groups except the multimodal group; there were no significant between-group differences in change scores ( P = .30). No significant between-group changes were seen for the TM walking, TBRS, and TM walking + TBRS groups for physical function measures.

CONCLUSION

This study demonstrates the clinical effectiveness of SET programs following current guidelines and potential utilization of non-TM walking modalities in SET programs.

Exploring telehealth interventions to monitor rehabilitation in patients with peripheral artery disease

Peripheral artery disease is a manifestation of systemic atherosclerosis, and these patients often have claudication pain in the legs during activity. This leads to generally adopting an inactive lifestyle; hence, even small changes in physical activity could reduce the risk of an adverse cardiovascular event. For patients with peripheral artery disease compliance with non-invasive interventions like assistive devices and long-term exercise therapy is important for improved health outcomes. Benefits to patients can only be measured if patients with peripheral artery disease adhere to the intervention and barriers are identified with improved solutions. The effect of mobile health including pedometers and smartphone technological applications in motivating the patient to continue adhering to the intervention and persist in physical activity is a new venture to be explored.

Looking back: a review of policy implications for exercise oncology

The evidence to support the benefits of exercise for people living with and beyond cancer is robust. Still, exercise oncology interventions in the United States are only eligible for coverage by third-party payers within the restrictions of cancer rehabilitation settings. Without expanded coverage, access will remain highly inequitable, tending toward the most well-resourced. This article describes the pathway to third-party coverage for 3 programs that address a chronic disease and utilize exercise professionals: the Diabetes Prevention Program, Supervised Exercise Training for Peripheral Artery Disease, and Cancer Rehabilitation. Lessons learned will be applied toward expanding third-party coverage for exercise oncology programming.

Home-Based Exercise Therapy in the Management of Intermittent Claudication: A Systematic Review and Meta-Analysis

The current literature strongly supports the use of supervised exercise therapy (SET) as the first-line treatment for symptomatic peripheral arterial disease (PAD) such as intermittent claudication (IC). However, this form of treatment remains underutilised in clinical practice. The home-based exercise therapy (HBET), in which patients must conduct themselves unsupervised is generally less effective than SET in terms of improving functional walking capacity. Nevertheless, it may be a useful alternative where SET is unavailable. The objective of this systematic review is to determine the effectiveness of HBET in reducing symptoms of IC in patients with PAD. Studies eligible for inclusion in this systematic review were parallel-group randomised controlled trials (RCTs) published in the English language that compared the effect of HBET to a comparator arm (SET or no exercise/attention control) in adults with PAD and IC. Studies were eligible if outcome measures were available at baseline and at 12 weeks of follow-up or more. The electronic databases PubMed, Google Scholar, and the Cochrane Library were searched from the earliest records up to January 2021. The Cochrane Collaboration risk of bias tool for RCTs (RoB 2) was used to assess the risk of bias in individual studies, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) classification system was used to appraise the quality of evidence for each outcome across all studies. The primary investigator independently collected, pooled, and analysed the data. The data was then entered into the ReviewManager 5 (RevMan 5) software, and a meta-analysis was performed by using a fixed or random effects model depending on the presence or absence of statistical heterogeneity. The review author identified seven RCTs involving a total of 754 patients which were included in this study. Overall, the risk of bias in the included studies was moderate. Even though the results were variable, this analysis supported the ability of HBET to improve functional walking capacity and self-reported quality of life (QoL) to an extent. This review shows that a home-based exercise intervention with regular professional support and encouragement is beneficial in improving functional walking capacity as well as some aspects of QoL in patients with PAD and IC when compared to no exercise. However, when HBET is compared to hospital-based supervised exercise intervention, SET yields greater benefits.

Medical Management of Peripheral Artery Disease

Peripheral artery disease (PAD) is a common type of atherosclerotic disease of the lower extremities associated with reduced quality of life and ambulatory capacity. Major adverse cardiovascular events and limb amputations are the leading cause of morbidity and mortality in this population. Optimal medical therapy is therefore critical in these patients to prevent adverse events. Risk factor modifications, including blood pressure control and smoking cessation, in addition to antithrombotic agents, peripheral vasodilators, and supervised exercise therapy are key pillars of medical therapy. Revascularization procedures represent key touch points between patients and health care providers and serve as opportunities to optimize medical therapy and improve long-term patency rates and outcomes. This review summarizes the aspects of medical therapy that all providers should be familiar with when caring for patients with PAD in the peri-revascularization period.

Sit to Stand Muscle Power Is Related to Functional Performance at Baseline and After Supervised Exercise Training in Patients with Lower Extremity Peripheral Artery Disease

OBJECTIVE

Patients with peripheral artery disease (PAD) have decreased muscle power, contributing to functional limitations. The sit to stand (STS) is a validated test to assess muscle power in older individuals; however, it has never been investigated in patients with PAD. The relationship between STS muscle power, and common disease related outcomes was evaluated at baseline and following supervised exercise training (SET) in patients with PAD.

METHODS

This observational study investigated patients with Fontaine stage II. Before and after SET, maximum treadmill walking distance (MWD), functional performance tests (six minute walk, STS, stair climbing, habitual gait speed), and quality of life (Short Form 36 questionnaire) were assessed. Relative (W/kg) STS muscle power was calculated using a validated equation. Multiple regressions models were used.

RESULTS

Ninety-five patients with PAD were included (63.1 ± 12.1 years, 67% male). Relative STS muscle power before: 2.7 W/kg, 95% confidence interval [CI] 2.5 - 2.9; after: 3.3, 95% CI 3.1 - 3.6, MWD before: 367.0 m, 95% CI 302.4 - 431.5; after: 598.4, 95% CI 515.6 - 681.3, six minute walking distance before: 418.3 metres; 95% CI 399.4 - 437.2; after: 468.8; 95% CI 452.7-484.9, stair climbing performance before: 6.8 seconds 95% CI 6.2 - 7.4); after: 5.3; 95% CI 4.9 - 5.7, habitual gait speed before: 1.10 m/s, 95% CI 1.05 - 1.14; after: 1.18, 95% CI 1.14 - 1.22 increased significantly following SET (p < .001). Similarly, physical before: 31.4, 95% CI 29.4 - 33.3; after: 35.8, 95% CI 33.9 - 37.7 and mental before: 39.5, 95% CI 37.0 - 42.0; after: 43.1, 95% CI 40.9 - 45.4 component summaries of the SF-36 also increased significantly (p < .001). Greater relative STS muscle power at baseline was significantly related to greater baseline treadmill (β < .380; p < .002) and functional (β < .597; p < .001) performance, and quality of life (β < .291; p < .050). Larger increases in relative STS muscle power following SET were associated with greater improvements in functional performance (β < .419; p < .009).

CONCLUSION

The STS test is a valid clinical tool to monitor overall functional status in patients with symptomatic PAD.

Diabetes Is Negatively Associated With Meeting Physical Activity Time-Intensity Guidelines in Patients With Claudication

PURPOSES

We determined the percentage of patients with peripheral artery disease (PAD) and claudication who meet the 2018 physical activity (PA) time-intensity guidelines, and we identified the clinical characteristics associated with the status of meeting the guidelines.

METHODS

Five hundred seventy-two patients were assessed on their daily ambulatory activity for 1 wk with a step activity monitor, and were evaluated on whether or not they achieved 150 min/wk of moderate-intensity PA.

RESULTS

Thirty-one percent (n = 175) of the patients with PAD met the PA time-intensity guidelines and 69% (n = 397) did not. In a final multivariable logistic regression model identifying the independent predictors of meeting the PA time-intensity guidelines from clinical characteristics, diabetes was the only significant variable entered (OR = 0.310: 95% CI, 0.175-0.538; P < .001) and was associated with a 69% lower chance of meeting the guidelines. Patients with diabetes spent less daily time in moderate-intensity ambulatory PA than patients without diabetes (15 ± 13 vs 23 ± 20 min/d; P < .001).

CONCLUSIONS

Thirty-one percent of patients with PAD and claudication met the PA time-intensity guidelines. Furthermore, patients with diabetes were least likely to meet the PA time-intensity guidelines, as they had a 69% lower chance than patients without diabetes. The clinical significance is that PAD patients who have diabetes are particularly susceptible to being physically sedentary, and are therefore prime patients who should be encouraged to increase their daily PA.

Long-term use of an ankle-foot orthosis intervention in patients with peripheral artery disease using the integrated promoting action on research implementation in health services (i-PARIHS) framework

BACKGROUND

Peripheral artery disease (PAD) is a cardiovascular disease that limits patients' walking ability. Persistent ankle-foot orthosis (AFO) use may increase the distance patients can walk as well as physical activity.

PURPOSE

The purpose of the study was to determine the implementation and patients' perspectives related to the use or disuse of the AFO intervention six months post-intervention. This study was guided by a semi-structured interview and survey based on the integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) constructs.

DESIGN

A convergent mixed methods design was used to evaluate participants' perceptions six months following a three-month AFO intervention. A survey and semi-structured questionnaire based on the i-PARIHS constructs were administered and analyzed.

SETTING

Vascular surgery clinic and biomechanics research laboratory.

PARTICIPANTS

Patients (N = 7; male, 100%; age, 71.9 ± 0.6.7y; body mass index, 29.0 ± 0.5.5; ankle brachial index 0.50 ± 0.17) with claudication completed the study.

INTERVENTIONS

A certified orthotist fit participants with an AFO that was worn for 3 months.

MAIN OUTCOME MEASURES

Qualitative analysis of semi-structured interviews and quantitative analysis of the survey.

RESULTS

The highest positive ratings were seen in the dimensions of usability and cost-effectiveness. The patients found the AFO device and instructions to wear, easy when starting the intervention and there were no out-of-pocket costs. The lower scores and challenges faced with observability and relative advantage domains indicated issues related to motivation for sustained use of the AFO.

CONCLUSIONS

Barriers associated with AFO function that prevent common activities and poor health seem to be the biggest issue for not wanting to wear the AFO after the 3-month intervention. Addressing patients' perceptions and challenges to wearing the AFO is essential to increasing compliance and physical activity. Future research should concentrate on understanding the compatibility of orthotic device interventions with the subject's lifestyle.

CLINICAL TRIAL REGISTRATION NO

NCT02902211.

A biomechanical perspective on walking in patients with peripheral artery disease

The most common symptom of peripheral artery disease (PAD) is intermittent claudication, which consists of debilitating leg pain during walking. In clinical settings, the presence of PAD is often noninvasively evaluated using the ankle-brachial index and imaging of the arterial supply. Furthermore, various questionnaires and functional tests are commonly used to measure the severity and negative effect of PAD on quality of life. However, these evaluations only provide information on vascular insufficiency and severity of the disease, but not regarding the complex mechanisms underlying walking impairments in patients with PAD. Biomechanical analyses using motion capture and ground reaction force measurements can provide insight into the underlying mechanisms to walking impairments in PAD. This review analyzes the application of biomechanics tools to identify gait impairments and their clinical implications on rehabilitation of patients with PAD. A total of 18 published journal articles focused on gait biomechanics in patients with PAD were studied. This narriative review shows that the gait of patients with PAD is impaired from the first steps that a patient takes and deteriorates further after the onset of claudication leg pain. These results point toward impaired muscle function across the ankle, knee, and hip joints during walking. Gait analysis helps understand the mechanisms operating in PAD and could also facilitate earlier diagnosis, better treatment, and slower progression of PAD.

Identifying potentially avoidable femoral to popliteal expanded polytetrafluoroethylene bypass for claudication using cross-site blinded peer review

OBJECTIVE

The surgical treatment of claudication can be associated with significant morbidity and costs. There are growing concerns that some patients proceed to interventions without first attempting evidence-based nonoperative management. We used a direct, cross-site, blinded expert review to evaluate the appropriateness of the surgical treatment of claudication.

METHODS

We enlisted practicing vascular surgeons to perform retrospective clinical assessments of lower extremity bypass procedures in a statewide clinical registry. Cases were limited to elective, open, infrainguinal bypasses performed for claudication using prosthetic grafts. Reviewing surgeons were randomly assigned 10 cases from a sample of 139 anonymized bypass operations and instructed to evaluate procedural appropriateness based on their expert opinion and evidence-based guidelines for preoperative treatment, namely, antiplatelet, statin, cilostazol, exercise, and smoking cessation therapy as documented in the medical record. Ninety-day episode payments were estimated from a distinct but similar cohort of patients undergoing lower extremity bypass for claudication.

RESULTS

Of 325 total reviews, surgeons stated they would not have recommended bypass in 134 reviews (41%) and deemed bypass inappropriate in 122 reviews (38%). The most common reason for inappropriateness was lack of preoperative medical and lifestyle therapy, which was present in 63% of reviews where bypass was deemed appropriate and 39% of reviews where bypass was deemed inappropriate (P < .001). Surgeons stated they would have recommended additional preoperative therapy in 65% of reviews where bypass was deemed inappropriate and 35% of reviews where bypass was deemed appropriate (P < .001). The mean total episode payments in a similar cohort of 1458 patients undergoing elective open lower extremity bypass for claudication were $31,301 ± $21,219. Extrapolating to the 325 reviews, the 134 reviews in which surgeons would not have recommended bypass were associated with potentially avoidable estimated total payments of $4,194,334, and the 122 reviews in which bypass was deemed inappropriate were associated with potentially avoidable estimated total payments of $3,818,722.

CONCLUSIONS

In this cross-site expert peer review study, 40% of lower extremity bypasses were deemed premature and, therefore, potentially avoidable, primarily owing to a lack of medical and lifestyle management before surgery. Reviews deemed inappropriate were associated with approximately $4 million in potentially avoidable costs. This approach could inform performance feedback among surgeons to help align clinical practice with evidence-based recommendations for the treatment of claudication.

Barriers to participation in supervised exercise therapy reported by people with peripheral artery disease

OBJECTIVE

This study identified barriers to participation in supervised exercise therapy covered by the Centers for Medicare and Medicaid Services (CMS), reported by people with lower extremity peripheral artery disease (PAD).

METHODS

People with PAD participating in research studies of walking impairment due to PAD in the Chicagoland area were asked to complete a questionnaire between March 15, 2019, and July 12, 2022, assessing their experience and attitudes about supervised exercise therapy. Participants were identified using mailed postcards to people aged 50 and older in Chicagoland, from medical centers in Chicago, and using bus and train advertisements. The questionnaire was developed based on focus group feedback from people with PAD.

RESULTS

Of 516 participants with PAD approached, 489 (94.8%) completed the questionnaire (mean age: 71.0 years [standard deviation: 8.7], mean ankle-brachial index: 0.71 [standard deviation: 0.25]; 204 [41.7%] women and 261 [53.4%] Black). Of the 489 participants, 416 (85.1%) reported that their physician had never prescribed or recommended supervised exercise therapy. Overall, 357 (73.2%) reported willingness to travel three times weekly to the medical center for supervised exercise participation. However, of these, 214 (59.9%) reported that they were unwilling or unable to pay the $11 per exercise session copay required for supervised exercise covered by CMS. Of 51 people with PAD who reported prior participation in supervised exercise, only 5 (9.8%) completed the 12 weeks of supervised exercise therapy covered by CMS and 29 (56.9%) completed 6 or fewer weeks. Of 131 (26.8%) unwilling to travel three times weekly to a center for supervised exercise, the most common reasons for unwillingness to participate were "too time-consuming" (55.0%), "too inconvenient" (45.8%), and "lack of interest in treadmill exercise" (28.2%).

CONCLUSIONS

Approximately 2 to 4 years after CMS began covering supervised exercise for PAD, most people with PAD in this study from a large urban area had not participated in supervised exercise therapy. Of those who participated, most completed fewer than half of the sessions covered by CMS. The required CMS copayment was a common barrier to supervised exercise participation by people with PAD.

Supervised Exercise Therapy for Symptomatic Peripheral Artery Disease: A REVIEW OF CURRENT EXPERIENCE AND PRACTICE-BASED RECOMMENDATIONS

PURPOSE

This review encompasses several practical components of supervised exercise therapy (SET) for patients with claudication including referral, exercise training, and billing issues. Real-life SET session examples are also provided. SET was approved for reimbursement by the Centers for Medicare & Medicaid Services (CMS) in 2017, and there is continual growth of programs offering SET and in participation. The purpose of this review is to provide useful information for the clinical exercise professionals working with these patients.

REVIEW METHODS

The 2016 ACC/AHA Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease (PAD) provided a class I (highest level) recommendation for the use of SET in those with symptomatic PAD. Since there has been much growth in the literature about the utility of SET, the literature was reviewed (PubMed) to provide information for this article. Topics reviewed include the benefits of exercise training, exercise prescription, billing, referral and participation, and best practices.

SUMMARY

SET should be offered to all patients with symptomatic PAD who are not at risk of acute limb ischemia. For optimal results, SET should be implemented several times per week and in a progressive process to increase exercise intensity as tolerated. For best results, programs should recommend patients supplement SET with home exercise. Considerations for utilizing reimbursed sessions should also be discussed because patients have a maximum of 72 sessions/lifetime. Referral practices need refinement, and participation rates remain extremely low and may be influenced by demographics. Research on best practices and home or hybrid training must continue to address issues related to common enrollment and participation barriers.

CONDENSED ABSTRACT

Supervised exercise training (SET) for symptomatic peripheral artery disease is a class IA recommendation and reimbursable by most insurances. Improvements in walking performance can be dramatic. However, referral and participation in SET remain very low and thus SET is vastly underutilized.

Non-surgical treatment for arterial leg ulcers: a narrative review

Objectives:

Arterial leg ulcers (ALUs) pose a considerable burden on patients and health services. The cornerstone of treatment is revascularisation; however, this is not always possible and does not necessarily guarantee ulcer healing. Alternative treatment options are therefore also important. This narrative review aims to summarise the evidence available for non-surgical treatment of ALUs, including topical therapy, pharmacological agents, therapeutic angiogenesis and devices.

Methods:

A literature search was performed in November 2020 to identify studies reporting data on the non-surgical management of ALUs. Prospective randomised controlled trials (RCTs), controlled clinical trials and meta-analyses that investigated conservative or medical interventions on patients with intractable ALUs, and which provided quantitative data on ulcer healing were included. Following screening, studies that met the inclusion criteria underwent a data extraction process and findings were synthesised and categorised narratively.

Results:

In total, 14 controlled trials were selected for inclusion and analysed based on experimental protocol and outcome measures.

Conclusion:

There is some evidence available for the use of short-term systemic prostanoids, ultrasound therapy and pneumatic compression. There are limitations to these options including side effects, patient tolerance due to pain and availability in clinical practice. Further research is needed to improve treatment options for this complex group.

Use of an App-Based Exercise Therapy Program Including Cognitive Behavioral Techniques for the Management of Intermittent Claudication

OBJECTIVES

Clinical practice guidelines recommend supervised exercise therapy (SET) as first-line therapy for patients with peripheral artery disease (PAD) and intermittent claudication (IC). The Society for Vascular Surgery (SVS) Appropriate Use Criteria (AUC) for IC deems exercise therapy as appropriate for all patients with IC. However, compliance with recommendations for the use of exercise therapy is often poor due to the lack of availability, patient travel requirements, and cost. Results of home-based exercise therapy programs have been mixed with a trend towards improved results with more frequent patient engagement. The feasibility, utilization, and effectiveness of a 12-week app-based structured exercise therapy program using cognitive behavioral techniques (CBT) for IC was evaluated.

METHODS

Patients with PAD (confirmed by abnormal ABI or TBI) and IC were recruited prospectively to participate in SVS SET, a 12-week app-based exercise therapy program. Participants performed home six-minute walk tests, completed quality of life (QoL) surveys, received education options via micro training courses (What is PAD?, Exercise, Nutrition), and ongoing health coaching utilizing CBT. They were instructed to record at least three 30-minute exercise therapy walks a week using their personal mobile phones. Programming also included "daily doses" of health education, coaching and reminders sent via text message.

RESULTS

One hundred and thirty-nine patients (37% women, mean age 65) were enrolled across 20 institutions (44% offered in-person exercise therapy programs). One hundred twenty (86%) of patients completed the program. Participants recorded 201,163 minutes of walking 8,013,520 steps with the exercise therapy program, completing a total of 5,049 SET Walks. Nineteen (14%) of enrolled participants became inactive because they either paused (14 participants: medical reasons, travel, or other) or withdrew (5 participants: security concerns, lack of motivation). Ninety-two percent of patients met their stated CBT SMART (Specific, Measurable, Achievable, Relevant, and Time-Bound) goals. Freedom from intervention at 6 months was 92% and 69% at 12 months.

CONCLUSIONS

Deployment of a 12-Week app-based exercise therapy program for PAD incorporating CBT was feasible in achieving 86% program completion and effective at meeting guideline recommended activity goals. Ninety-two percent of participants achieved their CBT SMART goals. Utilization of exercise therapy was increased by virtue of offering this program at institutions which did not offer exercise therapy.

Epidemiology of Peripheral Artery Disease: Narrative Review

Past decades have witnessed a major epidemiologic transition with a considerable increase in the disease burden associated with atherosclerotic cardiovascular diseases (CVDs), with low-income and middle-income countries (LMICs) experiencing substantial increase in CVDs. As the global population is aging and peripheral artery disease (PAD) is strongly age-related, it is estimated to become increasingly prevalent in the future. PAD shares risk factors with coronary and cerebrovascular risk factors, particularly diabetes mellitus and smoking, and is associated with significant CVD morbidity and mortality. Despite advances in therapeutic modalities, 236 million people were estimated to be suffering from PAD worldwide in 2015, and numbers have been rising since. The prevalence of asymptomatic PAD has remained high; PAD prevalence seems higher among women and is related to ethnicity. Although several epidemiological studies have been published on PAD during the past decades, data from LMICs are scarce. Besides providing up-to-date epidemiological data retrieved from the literature and the Global Burden of Disease (GBD) study database, this narrative review also intends to draw attention to the substantial disease burden of PAD manifesting in more Years of Life Lost (YLL), age-adjusted mortality and amputation rates, with a special focus on some European countries and especially Hungary, i.e., the country with the highest amputation rate in Europe.

Current Management of Peripheral Artery Disease: Focus on Pharmacotherapy

Peripheral artery disease (PAD) is the occlusion or narrowing of the arteries supplying the lower extremities. Peripheral artery disease has been estimated to affect approximately 240 million people worldwide, approximately 70% of whom are within low- or middle-income countries. Due to the ageing population and diabetes epidemic, the prevalence of PAD is rapidly rising. The symptoms of PAD are heterogeneous and thus a high index of suspicion is needed to prevent delays in diagnosis and treatment. Measurement of ankle brachial pressure index or arterial duplex ultrasound are traditionally used to diagnose PAD. Patients with PAD have a high risk of major adverse cardiovascular events. Early diagnosis and implementation of secondary cardiovascular prevention is therefore critical. This includes therapies to reduce low-density lipoprotein cholesterol, such as statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, blood-pressure reducing medications and anti-thrombotic drugs. Treatments to facilitate smoking cessation and control blood sugar if relevant and an exercise programme are also critical in reducing cardiovascular risk. Currently, these treatments are not well implemented. This review summarises the clinical presentation, risk factors and medical management of PAD. Global efforts are needed to reduce the burden from the growing PAD epidemic by implementing best practices and improving outcomes through further research.

A Systematic Review on Smartphone Use for Activity Monitoring During Exercise Therapy in Intermittent Claudication

OBJECTIVE

Supervised exercise therapy (SET) is recommended as first line in the management of intermittent claudication (IC). Its use is often limited by accessibility, compliance and cost. Home-based exercise therapy (HBET) programs emerged as an alternative solution, but have shown inferior results. Employment of structured monitoring with the use of external wearable activity monitors (WAM) has been shown to improve outcomes. Mobile applications can make use of built-in accelerometers of modern smartphones and become an alternative solution for monitoring patients during HBET, potentially providing wider accessibility. This review aims to assess current use of smartphone technology (i.e., mobile apps) for monitoring or tracking patients' activity in exercise therapy for peripheral arterial disease (PAD).

METHODS

The PubMed database was searched from January 2011 to September 2021. Eligible articles had to include a population of patients with PAD, conduct a mobile-health (m-health) exercise intervention and use smartphone technology for monitoring or tracking patients' activity. Randomized control trials (RCTs), prospective studies, and study protocols were included.

RESULTS

A total of seven articles met the selection criteria. These described six different studies and five different mobile applications. Three were fitness apps (FitBit, Nike+ FuelBand and Garmin Connect) that synchronized with commercially available WAMs to provide users with feedback. Two were PAD-specific apps (TrackPAD and Movn) developed specifically to assess patients' activity during exercise therapy. PAD-specific apps also incorporated coaching and educational elements such as weekly goal setting, claudication reminders, messaging, gamification, training advice and PAD education.

CONCLUSION

Current HBET programs use smartphone applications mainly via commercially available fitness apps that synchronize with WAM devices to register and access data. PAD-specific apps are scarce but show promising features that can be used to monitor, train, coach, and educate patients during HBET programs. Larger studies combining these elements into HBET programs should provide future direction.

Underutilization of Medical Management of Peripheral Artery Disease Among Patients with Claudication Undergoing Lower Extremity Bypass

OBJECTIVE

First-line treatment of peripheral artery disease (PAD) involves medical therapy and lifestyle modification. Multiple professional organizations such as the Society for Vascular Surgery (SVS) and the American Heart Association/American College of Cardiology (AHA/ACC) make Class I recommendations for medical management including antiplatelet, statin, antihypertensive, and cilostazol medications, as well as lifestyle therapy including exercise and smoking cessation. Although evidence supports up-front medical and lifestyle management prior to surgical intervention, it is unclear how well this occurs in contemporary clinical practice. It is also unclear whether variability in first-line treatment prior to revascularization is associated with postoperative outcomes. This study examined the proportion of patients with claudication actively receiving evidence-based therapy prior to surgery in a statewide surgical registry.

METHODS

We conducted a retrospective cohort study of adult patients undergoing elective open lower extremity bypass for claudication from 2012-2021 within a statewide surgical quality registry. The primary exposure was optimal medical therapy defined as an antiplatelet agent, a statin, and an angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) (if the patient had hypertension) on the patient's home medication list on admission for surgery, all of which are Class I recommendations. Despite also being Class I recommendations, cilostazol was not included in the primary exposure due to its highly selective use and our inability to capture intolerance and/or contraindications which are common, and lifestyle therapies were not included as they were only recorded at the time of discharge rather than preoperatively. The primary outcomes were mortality, hospital readmission, amputation, wound complication, myocardial infarction (MI), non-patent bypass, and non-independent ambulatory status at 30 days and 1 year after surgery. Multivariable logistic regression was performed to estimate the association of receiving optimal vs. non-optimal medical therapy.

RESULTS

3,829 patients with claudication underwent bypass surgery during the study period, with a mean age of 64.8 (9.8) years, 2,690 (70.3%) males, and 1,873 (48.9%) current smokers. 1,822 (47.6%) patients were on optimal medical therapy prior to surgery. Additionally, at discharge, 66.5% of smokers received referral to smoking cessation therapy and 54.1% of patients received referral to exercise therapy. In a multivariable logistic regression, compared to patients not on optimal medical therapy, patients on optimal medical therapy prior to surgery had lower 30-day odds of mortality (aOR 0.45 [95% CI 0.26-0.78]) and MI (aOR 0.46 [95% CI 0.28-0.76]) and lower 1-year odds of mortality (aOR 0.57 [95% CI 0.39-0.82]), MI (aOR 0.48 [95% CI 0.32-0.74]), and readmission (aOR 0.79 [95% CI 0.64-0.96]).

CONCLUSION

Although medical and lifestyle management is recommended as first-line treatment for patients with PAD, only half of patients were on optimal medical therapy prior to surgery. Patients receiving optimal therapy had a lower risk of postoperative mortality, MI, and readmission. This suggests that not only are there significant opportunities to improve clinical utilization of evidence-based treatment of PAD, but that doing so can benefit patients postoperatively.

Comorbid Depression is Associated with Increased Major Adverse Limb Events in Peripheral Arterial Disease: A systematic review and meta-analysis

OBJECTIVE

Depression is a significant risk factor for mortality in coronary artery disease. On the contrary, the research surrounding depression and peripheral arterial disease is limited. This review aims to systematically evaluate the available literature on the impact of comorbid depression on adverse outcomes in peripheral arterial disease.

DATA SOURCES

A systematic review and meta-analysis were performed using the following databases: MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Library from inception until July 2021.

REVIEW METHODS

Included studies compared depressed and non-depressed patients with peripheral arterial disease. The outcomes included mortality, major adverse cardiovascular events, and major adverse limb events.

RESULTS

A total of 9 297 articles were searched. Of these, seven studies were identified. Depressed patients were more likely to be women, be diabetic, have a history of smoking, and have chronic limb threatening ischemia, despite being younger than non-depressed patients. There was a 20% increase in major adverse limb events in depressed patients [RR 1.20, 95% CI (1.11 - 1.31), z =3.9, p<.001, GRADE strength: very low] but no increased risk of mortality [RR 1.03, 95% CI (0.72-1.40), z =0.06, p =.95. GRADE strength: very low] or major adverse cardiovascular events [RR 1.16, 95% CI (0.67 - 2.01), z =0.54, p =.59, GRADE strength: very low]. A follow-up meta-regression of various comorbidities and demographic variables did not demonstrate a significant contribution to the observed risk ratio for major adverse limb events.

CONCLUSION

Depression was reported in 13% of peripheral arterial disease patients, associated with more medical comorbidity, and a 20% increased risk of major adverse limb events. Although the strength of this evidence is very low, the current state of the literature is still limited. Future studies should prospectively assess the impact of depression and its relationship with medical comorbidities and high risk health behaviors.

WalkingPad protocol: a randomized clinical trial of behavioral and motivational intervention added to smartphone-enabled supervised home-based exercise in patients with peripheral arterial disease and intermittent claudication

Background

Physical exercise is a first-line treatment for peripheral arterial disease (PAD) and intermittent claudication (IC) reducing pain and increasing the distances walked. Home-based exercise therapy (HBET) has the advantage of reaching a higher number of patients and increasing adherence to physical exercise as it is performed in the patient’s residential area and does not have the time, cost, and access restrictions of supervised exercise therapy (SET) implemented in a clinical setting. Even so, rates of adherence to physical exercise are relatively low, and therefore, m-health tools are promising in increasing motivation to behavior change and adherence to physical exercise. A built-in virtual assistant is a patient-focused tool available in a mobile interface, providing a variety of functions including health education, motivation, and implementation of behavior change techniques.

Methods

This is a single-center, prospective, three-arm, single-blind, randomized, controlled, superior clinical trial with stratified and blocked random allocation. Three hundred participants with PAD and IC will be recruited from an Angiology and Vascular Surgery Department, Centro Hospitalar Universitário Porto (CHUPorto), Porto, Portugal. All patients will receive the same medical care recommended by  current guidelines. Participants in all three groups will receive a personalized prescription for an HBET program and a behavioral change and motivational intervention. Participants in experimental groups 1 and 2 will receive a smartphone with the WalkingPad app to monitor exercise sessions. Experimental group 2 WalkingPad app will have a built-in virtual assistant that will promote behavioral change and provide motivational support. Participants allocated to the active control group will not receive the m-health tool, but a practice diary to encourage monitoring. The  program will last for 6 months with three evaluation moments (baseline, 3, and 6 months). The primary outcome will be the change in distances walked (maximal and pain-free) from baseline to 3 and 6 months. Secondary outcomes will be changes in quality of life, patients’ perception of resistance, and walking speed.

Discussion

This study will allow measuring the effectiveness of an m-health tool in increasing motivation for behavior change and adherence to an HBET program in patients with PAD. The superiority of experimental group 2 in the primary and secondary outcomes will indicate that the virtual assistant is effective for motivating behavioral change and encouraging the practice and adherence to physical exercise. The use of m-health tools and virtual health assistants can potentially fill a gap in the access and quality of health services and information, reducing the burden on the health system and promoting self-management and self-care in chronic illness.

Trial registration

ClinicalTrials.govNCT04749732. Registered on 10 February 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06279-9.

Supervised exercise therapy for patients with peripheral artery disease: Clinical update and pathways forward

Peripheral artery disease (PAD) is an atherosclerotic vascular disease resulting in widespread morbidity and mortality, particularly among older adults. One first-line therapy to improve symptoms, function, and clinical outcomes in PAD is supervised exercise therapy (SET), which is based primarily on a structured, start-and-stop walking protocol and is implemented in cardiac rehabilitation programs. SET is supported by a Class IA guideline for patients with symptomatic PAD; however, despite the effectiveness of SET and the 2017 CMS decision to cover SET for PAD, challenges of awareness, access, and implementation of SET persist. Recent efforts to address these challenges include digital health and hybrid approaches to SET that may minimize barriers to care by delivering SET in more innovative, flexible formats. Further study is needed to understand barriers, improve awareness, and implement SET in more equitable and accessible ways.

Sex as a Key Determinant of Peripheral Artery Disease – Epidemiology, Differential Outcomes, and Proposed Biological Mechanisms

Atherosclerotic peripheral artery disease (PAD) is associated with functional limitations and an increased risk of poor cardiovascular outcomes. Although men are traditionally viewed at higher risk of PAD than women, the true prevalence and incidence is inconsistent among available reports. Some of this variability is due to differences in PAD-related symptoms among women as well as sex-based differences in diagnostic tests, such as the ankle-brachial index, and it is critical for future epidemiologic studies to account for these differences. Generally, women with PAD experience greater functional impairment and decline then men and are less likely to receive guideline-directed medical therapy. In some settings, women are also more likely to present at later stages of disease and more often undergo lower limb amputation than men. Animal data exploring the biological underpinnings of these sex differences are limited, but several mechanisms have been postulated, including differential plaque morphology, alterations in the immune response, and hormonal variation and protection. Epidemiologic data suggest a link between inflammation and PAD and also reveal sex differences in lipid profiles associated with risk of PAD. In this review, we discuss available data on sex differences in PAD with additional focus on potential biological explanations for these differences. We also emphasize important knowledge gaps in this area, including under-representation of women in PAD clinical trials, to help guide future investigations and eliminate sex disparities in PAD.

Supervised Cycling Training Improves Erythrocyte Rheology in Individuals With Peripheral Arterial Disease

Peripheral arterial disease (PAD) results in insufficient flow to lower extremities. Aerobic exercise provides health benefits for individuals with PAD, but basic science behind it is still debated. Twenty-one PAD patients aged about 70 years with female/male as 7/14 were recruited. Among them, 11 were randomized to have supervised cycling training (SCT) and 10 to receive general healthcare (GHC) as controls. SCT participants completed 36 sessions of SCT at the first ventilation threshold within 12 weeks and the controls received GHC for 12 weeks. Ankle-brachial index (ABI), 6-min walk test (6MWT), peak oxygen consumption (V˙O_2peak), minute ventilation (V˙_E), minute carbon dioxide production (V˙CO₂), erythrocyte rheology, including the maximal elongation index (EI_max) and shear stress at 50% of maximal elongation (SS_1/2), and the Short Form-36 (SF-36) questionnaire for quality of life (QoL) were assessed before and 12 weeks after initial visit. SCT significantly decreased the SS_1/2 as well as SS_1/2 to EI_max ratio (SS_1/2/EI_max) and increased the erythrocyte osmolality in the hypertonic region as well as the area under EI-osmolality curve. The supervised exercise-induced improvement of erythrocyte deformability could contribute to the increased peripheral tissue O₂ delivery and was possibly related with increased V˙O_2peak. The physiological benefit was associated with significantly increased ABI, 6-min walking distance, cardiorespiratory fitness, and SF-36 score. However, no significant changes in aerobic capacity and erythrocyte rheological properties were observed after 12-week of GHC. In conclusion, SCT improves aerobic capacity by enhancing erythrocyte membrane deformability and consequently promotes QoL in PAD patients.

Total body recumbent stepping vs treadmill walking in supervised exercise therapy: A pilot study

Background: Treadmill walking is the most commonly recommended exercise modality in supervised exercise therapy (SET) for peripheral artery disease (PAD); however, other modalities may be equally effective and more tolerable for patients. The primary aim of this single-blind, randomized pilot study was to compare the feasibility, safety, and preliminary efficacy of a treadmill walking (TM) versus a total body recumbent stepping (TBRS) exercise program for treatment of PAD. Methods: Participants (n = 19) enrolled in a 12-week SET program and were randomized to either a TM (n = 9) or TBRS (n = 10) exercise group that followed current SET exercise guidelines. Feasibility, safety, and efficacy outcomes were assessed. Results: SET attendance was 86% and 71%, respectively, for TBRS and TM groups (p = 0.07). Session exercise dose (metabolic equivalents of task [MET] minutes) (mean [SD]) for TM was 117.6 [27.4] compared to 144.7 [28.7] in the TBRS group (p = 0.08). Study-related adverse events were nine in 236 training hours and three in 180 training hours for the TBRS and TM groups, respectively. There were no significant differences between groups for improvement in 6-minute walk distance (mean [SD]) (TM: 133.2 ft [53.5] vs TBRS: 154.8 ft [49.8]; p = 0.77) after adjusting for baseline 6-minute walk distance. Conclusion: This is the first randomized study comparing TBRS to TM exercise in SET using current SET guidelines. This pilot study showed that TBRS is a feasible and safe exercise modality in SET. This study provides preliminary efficacy of the use of TBRS exercise in SET programs following current guidelines. Larger studies should be conducted to confirm these findings.

Update on the pathophysiology and medical treatment of peripheral artery disease

Approximately 6% of adults worldwide have atherosclerosis and thrombosis of the lower limb arteries (peripheral artery disease (PAD)) and the prevalence is rising. PAD causes leg pain, impaired health-related quality of life, immobility, tissue loss and a high risk of major adverse events, including myocardial infarction, stroke, revascularization, amputation and death. In this Review, I describe the pathophysiology, presentation, outcome, preclinical research and medical management of PAD. Established treatments for PAD include antithrombotic drugs, such as aspirin and clopidogrel, and medications to treat dyslipidaemia, hypertension and diabetes mellitus. Randomized controlled trials have demonstrated that these treatments reduce the risk of major adverse events. The drug cilostazol, exercise therapy and revascularization are the current treatment options for the limb symptoms of PAD, but each has limitations. Novel therapies to promote collateral and new capillary growth and treat PAD-related myopathy are under investigation. Methods to improve the implementation of evidence-based medical management, novel drug therapies and rehabilitation programmes for PAD-related pain, functional impairment and ischaemic foot disease are important areas for future research.

Safety of home-based exercise for people with intermittent claudication: A systematic review

Intermittent claudication (IC) is a classic symptom of peripheral artery disease, with first line treatment being supervised exercise therapy (SET). Despite this, SET is frequently underutilised, and adherence is often poor. An alternative option are home-based exercise programmes (HBEP). Although HBEPs are well tolerated, to the authors’ knowledge, no research has assessed their safety. The aim of this review was to assess the safety of HBEPs in people living with IC. We performed an electronic search of the MEDLINE, CINAHL, and Cochrane Library databases. The main parameter of interest was complication rate, calculated as the number of related adverse events per patient-hours. Subanalysis was undertaken to determine differences in safety for studies that did and did not include pre-exercise cardiac screening, and for studies with exercise at low, moderate, and high levels of claudication pain. Our search strategy identified 8693 results, of which 27 studies were included for full review. Studies included 1642 participants completing 147,810 patient-hours of home-based exercise. Four related adverse events were reported, three of which were cardiac in origin, giving an all-cause complication rate of one event per 36,953 patient-hours. Three of these events occurred following exercise to high levels of claudication pain, and one occurred with pain-free exercise. One event occured in a study without cardiac screening. Based on the low number of related adverse events, HBEPs appear to be a safe method of exercise prescription for people with IC. Our results strengthen the rationale for providing alternative exercise options for this population. PROSPERO Registration No.: CRD42021254581

Intensity-dependent effects of exercise therapy on walking performance and aerobic fitness in symptomatic patients with lower-extremity peripheral artery disease: A systematic review and meta-analysis

We investigated how nonpain-based exercise therapy intensity (light-to-moderate or vigorous) affects improvements in walking performance and cardiorespiratory fitness of patients with symptomatic lower-extremity peripheral artery disease (PAD). We searched the Embase, MEDLINE, Cochrane, Web of Science, and Google Scholar databases up to April 2021 and included randomized controlled trials reporting training therapies targeting exercise intensity (heart rate, oxygen consumption, or perceived exertion). The main outcomes were walking performance (pain-free [PFWD] and maximal [MWD] walking distance) and cardiorespiratory fitness (V̇O_2peak). Secondary subanalyses examined the training modality (walking or other modalities) and the approach (high-intensity interval or moderate-intensity training). A total of 1132 patients were included. Light-to-moderate was superior to vigorous exercise intensity in improving MWD (223 m [95% CI 174 to 271], p < 0.00001; 153 m [95% CI 113 to 193], p < 0.00001; respectively) and PFWD (130 m [95% CI 87 to 173], p < 0.00001; 83 m [95% CI 61 to 104], p < 0.00001; respectively). When training modalities were considered, walking at a vigorous intensity (272 m [95% CI 207 to 337], p < 0.00001) showed the largest improvement in MWD compared to other exercise modalities. A larger increase in V̇O_2peak was observed following vigorous (3.0 mL O₂·kg^-1·min^-1 [95% CI 2.4 to 3.6], p < 0.00001) compared to light-to-moderate (1.1 mL O₂·kg^-1·min^-1 [95% CI 0.4 to 1.7], p = 0.001) exercise intensity. These results indicate that vigorous was less effective than light-to-moderate intensity in improving walking performance, whereas it was more effective in improving V̇O_2peak. When the training modalities were considered, walking at a vigorous intensity showed the greatest improvement in MWD. (PROSPERO Registration No.: CRD42020199469).

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.