Home-based walking exercise intervention in peripheral artery disease: a randomized clinical trial

Related factors associated with exercise behavior in patients with peripheral arterial disease

[Purpose] This study aimed to identify the factors associated with exercise behavior in patients with peripheral arterial disease. [Participants and Methods] The study included 43 patients with peripheral arterial disease (mean age, 75.2 ± 5.6 years) who were admitted for endovascular treatment from January 2020 to June 2021. Participants were surveyed through questionnaires to assess their physical function for determining their exercise behavior and the presence of physical, personal, and environmental factors that might have affected their stage of change regarding exercise behavior. [Results] A comparison of physical, personal, and environmental factors between the two groups classified by the presence or absence of exercise behavior showed that subjective health and exercise self-efficacy were significantly lower in the group without exercise. Furthermore, a difference was noted in the presence or absence of work. The adjusted binomial logistic regression analysis results using each of the factors differing between the groups, plus the walking impairment questionnaire total score as explanatory variables, showed a significant relationship with exercise self-efficacy only. [Conclusion] The results of this study showed that exercise self-efficacy presented a useful predictive relationship with the presence of exercise behavior in patients with peripheral arterial disease.

Connecting the past to the present: A historical review of exercise training for peripheral artery disease

Peripheral artery disease (PAD), a prevalent manifestation of atherosclerosis, is associated with increased cardiovascular morbidity and mortality as well as decreased functional ability. Exercise training for PAD is acknowledged to be a highly effective treatment, which improves walking ability and cardiovascular risk. The historical development of this treatment has not been the focus of a report. Therefore, we present a historical review of research on exercise training for PAD. Overall, this body of knowledge has provided strong evidence of the efficacy of supervised exercise training (SET) to improve walking ability for patients with claudication due to PAD. SET, using intermittent bouts of walking exercise to moderate claudication pain on a treadmill, is considered the most efficacious mode of exercise to improve walking ability in patients with claudication. This compelling evidence published over the past 60 years was evaluated by the Centers for Medicare & Medicaid Services in 2017, which culminated in a national coverage determination for SET to improve symptomatic PAD. Future directions include determining optimal delivery strategies for SET and further elucidation of the mechanisms of improvement in walking ability resulting from SET. In addition, alternative forms of exercise should be evaluated and effective home- and community-based exercise interventions should be assessed. There is an enormous need to increase the inclusion of women and racial and ethnic minority groups in studies. It is to be hoped that researchers will continue with new innovative research and persistence in the treatment of claudication due to PAD.

Minimal clinically important differences in daily physical activity outcomes following supervised and home-based exercise in peripheral artery disease

Introduction: We estimated minimal clinically important differences (MCID) for small, moderate, and large changes in daily step counts and time spent in moderate-to-vigorous physical activity (MVPA) following both supervised and home-based exercise programs in symptomatic patients with peripheral artery disease (PAD). Methods: Patients were randomized to either 12 weeks of a supervised exercise program (n = 60), a home-based exercise program (n = 60), or an attention-control group (n = 60). Results: Using the anchor-based method to determine MCID, the MCID value for a large change in health-related quality of life (HRQoL) was an increase of 1211 total daily steps and an increase in 11 minutes in the time spent in MVPA following 12 weeks of exercise intervention. Using the distribution-based method, the MCID values for small, moderate, and large changes in total daily steps in the home-based exercise group were 558, 1396, and 2233 steps/d, respectively, and the corresponding changes in the time spent in MVPA were 6, 15, and 23 minutes. Similar distribution-based MCID scores were noted for the supervised exercise group. Conclusion: Following 3 months of home-based and supervised exercise programs for patients with PAD and claudication, increases of 11 minutes in time spent in MVPA and 1211 total daily steps were associated with large anchor-based MCID increases in HRQoL. The clinical implication is that patients with PAD and claudication should be encouraged to increase daily steps, particularly by walking an additional 11 minutes each day in MVPA, which is associated with a large meaningful increase in HRQoL.

Use of a Smartphone App Versus Motivational Interviewing to Increase Walking Distance and Weight Loss in Overweight/Obese Adults With Peripheral Artery Disease: Pilot Randomized Trial

BACKGROUND

Walking therapy improves functional outcomes in patients with peripheral artery disease (PAD). Less is known about the additive benefit of a dietary intervention.

OBJECTIVE

Our objectives were to develop a smartphone app and, as a pilot, explore its potential efficacy as compared to motivational interviewing (MI) to increase walking distance and promote weight loss in overweight/obese adults with PAD.

METHODS

We conducted a 3-month, 2-arm randomized pilot study at the University of Kansas. Inclusion criteria were BMI >27 kg/m² and symptomatic PAD, defined by an ankle-brachial index <0.9. Patients were randomized into 2 groups: MI, delivered through in-person and telephone counseling, and app, a mobile smartphone app. Both interventions encouraged walking for exercise and healthy dietary habits (increasing fruits and vegetables and whole grains while reducing fat and sugary drinks). We assessed medical history at baseline. At baseline and 3 months, participants completed an assessment of 6-minute walking distance, weight, quality of life, exercise behaviors, and dietary habits. The primary outcome was 3-month change in walking distance. Secondary outcomes were changes in weight, quality of life, exercise behaviors, and dietary habits. We used a Wilcoxon rank-sum test to analyze the primary and secondary outcomes at 3 months within the MI and app groups and to compare the changes between the groups with adjustment for baseline.

RESULTS

We randomized 29 participants with a mean age of 66.03 (SD 8.12) years; 25 participants completed the trial. At baseline, mean walking distance among completers was 260.40 (SD 94.32) meters and 326.15 (SD 69.28) meters for MI and app participants, respectively. At 3 months, the mean walking distance was 298.67 (SD 101.20) meters and 331.19 (SD 58.63) meters for MI and app participants, respectively (group difference P=.03, adjusting for baseline). Increase in walking distance at 3 months was 40.5 meters (95% CI 6.77 to 61.34; P=.02) in MI group. At baseline, mean body weight was 253.10 (SD 59.45) lbs and 225.13 (SD 58.93) lbs for MI and app participants, respectively. At 3 months, mean body weight was 242.14 (SD 58.54) lbs and 223.44 (SD 59.54) lbs for MI and app, respectively (group difference P=.006, adjusting for baseline). Pre-post study decrease in weight was 10.1 lbs (95% CI -17.9 to -3.0) and 2.3 lbs (95% CI -3.4 to -0.7) in MI and app group, respectively. Comparing baseline to 3 months, there were no statistically significant differences in quality of life, exercise behaviors, or dietary habits.

CONCLUSIONS

Our study demonstrates that MI can promote walking and weight loss in overweight/obese adults with PAD. The smartphone app showed a small weight loss but no statistically significant increase in walking distance. As this was a pilot study, future large-scale studies are needed to replicate the efficacy of MI to promote weight loss in overweight or obese adults with PAD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03694652; https://clinicaltrials.gov/ct2/show/NCT03694652.

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.

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.

Cardiac Rehabilitation in Patients with Peripheral Artery Disease-A Literature Review in COVID-19 Era

Cardiac rehabilitation (CR) is an integral part of the management of various cardiovascular disease such as coronary artery disease (CAD), peripheral artery disease (PAD), or chronic heart failure (CHF), with proven morbidity and mortality benefits. This article aims to review and summarize the scientific literature related to cardiac rehabilitation programs for patients with PAD and how they were adapted during the COVID-19 pandemic. The implementation of CR programs has been problematic since the COVID-19 pandemic due to social distancing and work-related restrictions. One of the main challenges for physicians and health systems alike has been the management of PAD patients. COVID-19 predisposes to coagulation disorders that can lead to severe thrombotic events. Home-based walking exercises are more accessible and easier to accept than supervised exercise programs. Cycling or other forms of exercise are more entertaining or challenging alternatives to exercise therapy. Besides treadmill exercises, upper- and lower-extremity ergometry also has great functional benefits, especially regarding walking endurance. Supervised exercise therapy has a positive impact on both functional capacity and also on the quality of life of such patients. The most effective manner to acquire this seems to be by combining revascularization therapy and supervised exercise. Rehabilitation programs proved to be a mandatory part of the integrative approach in these cases, increasing quality of life, and decreasing stress levels, depression, and anxiety.

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

Comprehensive cardiac rehabilitation program for peripheral arterial diseases

Peripheral arterial disease (PAD) is a phenotype of atherosclerotic disease often associated with cerebrovascular or coronary artery disease. The incidence of cardiovascular events in patients with PAD is 5.4% per year, which is higher than that of cerebrovascular or coronary artery disease. The most useful screening method for PAD is the ankle brachial pressure index (ABI). The ABI should be measured in (1) all patients with lower limb symptoms such as claudication, (2) all patients aged 65 years and over, and (3) those aged 50 to 65 years who have risk factors such as smoking and diabetes mellitus. PAD is diagnosed if the ABI is <0.9. A comprehensive cardiac rehabilitation program includes complete smoking cessation, blood pressure control with antihypertensive medications and salt reduction for hypertension, glycemic control for diabetes mellitus, and appropriate medications such as antiplatelet agents and statins. A multidisciplinary team approach is effective in comprehensive cardiac rehabilitation for patients with PAD, even those with critical limb ischemia (CLI). Exercise therapy is a crucial and essential treatment for PAD, except in CLI. Exercise therapy is contraindicated in patients with acute arterial occlusion and CLI with infection. PAD is often associated with other atherosclerotic diseases; the patient should be monitored for ischemic heart disease during the initial exercise stress test using the Gardner treadmill protocol. Supervised exercise therapy is highly recommended (Class I, Level of Evidence A). Alternatively, a home-based exercise program is feasible (Class IIa, Level of Evidence A). The exercise type (treadmill, track walking, ergometer), frequency (3 to 5 days per week), intensity (speed and incline), and duration (30 minutes) are determined based on the exercise stress test results for each patient. Exercise should be continued at least 3 times a week for at least 12 weeks. Cilostazol is highly recommended (Class I, Level of Evidence A).

Walking Impairment Questionnaire and Walking Tests are Reliable Indicators of Success of Treatment of Peripheral Artery Disease

The functional capacity of patients with peripheral arterial disease (PAD) represents an important indicator of patient health and quality of life. The aim of this prospective study was to investigate the validity of a walking impairment questionnaire (WIQ) compared with walking tests for the estimation of the therapeutic effect of lower limb revascularization. The study included 36 patients with PAD in whom successful percutaneous revascularization of a lower limb was performed due to disabling intermittent claudication. Before the revascularization procedure and 4-6 weeks after successful revascularization, clinical examination, ankle brachial index (ABI) measurement, 6-min walk test, treadmill test, and WIQ were performed. After revascularization, significant improvement in walking capacity was shown by both 6-min walk test and treadmill exercise test as well as with WIQ. However, the increase in ABI was borderline. Significant correlations between improvement of 6-min walk test and treadmill exercise test results and the sum of WIQ points were found. The ABI was significantly correlated with treadmill maximal walking distance only. According to our results, the WIQ correlates well with walking tests and is a reliable indicator of effective revascularization of lower limb arterial occlusions, even in patients with a nonsignificant improvement of the ABI.

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.

Agreement Between StepWatch3 and ActiGraph wGT3X+ for Measuring Step-Based Metrics in People With Peripheral Artery Disease

The authors investigated the agreement between StepWatch3™ (SW3) and ActiGraph™ wGT3X+ monitors for measuring step-based metrics in patients with peripheral artery disease and older adults. In 23 patients with peripheral artery disease and 38 older participants, the authors compared the metrics obtained during an outdoor (400-m track) walking session (step count) and a 7-day free-living period (step count and 60/30/5/1-min maximal or peak step accumulation) using the SW3 (ankle) and the wGT3X+ (hip) with the low-frequency extension filter enabled (wGT3X+/LFE) or not (wGT3X+/N). During outdoor walking session, agreement was high, particularly for wGT3X+/LFE: correlations ≥.98, median absolute percentage errors <1%, and significant equivalence using a ± 15% equivalence zone or narrower. In free living, no wGT3X+ method was equivalent to SW3 for step count. The wGT3X+/LFE was equivalent to SW3 regarding all step accumulation metrics using a ± 20% equivalence zone or narrower, with median absolute percentage errors <11%. The wGT3X+/LFE method is the best option for comparisons with SW3 in peripheral artery disease and older adults.

Don't stop walking: the in-home rehabilitation program for peripheral artery disease patients during the COVID-19 pandemic

We studied the outcomes of peripheral artery disease (PAD) patients enrolled in a structured in-home walking program right before the lockdown due to the SARS-CoV-2 epidemic emergency, to determine whether this intervention ensured the maintenance of mobility even in the case of movement restrictions.We selectively studied 83 patients (age 72 ± 11, males n = 65) enrolled in the program within 9-month before the lockdown. The usual intervention was based on two daily 8-min sessions of slow intermittent in-home walking prescribed in circa-monthly hospital visits. During the lockdown, the program was updated by phone. Six-minute (6MWD) and pain-free walking distance (PFWD) were measured pre- and post-lockdown as well as body weight (BW), blood pressure (BP), and ankle-brachial index (ABI). Sixty-six patients were measured 117 ± 23 days after their previous visit. A safe, pain-free execution of the prescribed sessions was reported (median distance: 74 km). Overall, the 6MWD was stable, while PFWD improved (p < 0.001). The improvement was not related to age/gender, comorbidities, type of home but to the time of enrollment before lockdown. The new-entry subjects (≤ 3 months; n = 35) obtained significant improvements post-lockdown for 6MWD and PFWD, while those previously enrolled (> 3 months; n = 31) were stable. Decreased BW with stable BP and ABI values were also recorded, with better outcomes for new-entry subjects. In PAD patients, a structured walking program performed inside home and purposely guided by phone was adhered to by patients and favored mobility and risk factor control during the COVID-19 pandemic, regardless of walking ability, type of home and external conditions.

Endovascular Revascularization Plus Supervised Exercise Versus Supervised Exercise Only for Intermittent Claudication: A Cost-Effectiveness Analysis

[Figure: see text].

Contemporary Medical Management of Peripheral Artery Disease

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis. Modifiable risk factors including cigarette smoking, dyslipidemia, diabetes, poor diet quality, obesity, and physical inactivity, along with underlying genetic factors contribute to lower extremity atherosclerosis. Patients with PAD often have coexistent coronary or cerebrovascular disease, and increased likelihood of major adverse cardiovascular events, including myocardial infarction, stroke and cardiovascular death. Patients with PAD often have reduced walking capacity and are at risk of acute and chronic critical limb ischemia leading to major adverse limb events, such as peripheral revascularization or amputation. The presence of polyvascular disease identifies the highest risk patient group for major adverse cardiovascular events, and patients with prior critical limb ischemia, prior lower extremity revascularization, or amputation have a heightened risk of major adverse limb events. Medical therapies have demonstrated efficacy in reducing the risk of major adverse cardiovascular events and major adverse limb events, and improving function in patients with PAD by modulating key disease determining pathways including inflammation, vascular dysfunction, and metabolic disturbances. Treatment with guideline-recommended therapies, including smoking cessation, lipid lowering drugs, optimal glucose control, and antithrombotic medications lowers the incidence of major adverse cardiovascular events and major adverse limb events. Exercise training and cilostazol improve walking capacity. The heterogeneity of risk profile in patients with PAD supports a personalized approach, with consideration of treatment intensification in those at high risk of adverse events. This review highlights the medical therapies currently available to improve outcomes in patients with PAD.

Walking Exercise Therapy Effects on Lower Extremity Skeletal Muscle in Peripheral Artery Disease

Walking exercise is the most effective noninvasive therapy that improves walking ability in peripheral artery disease (PAD). Biologic mechanisms by which exercise improves walking in PAD are unclear. This review summarizes evidence regarding effects of walking exercise on lower extremity skeletal muscle in PAD. In older people without PAD, aerobic exercise improves mitochondrial activity, muscle mass, capillary density, and insulin sensitivity in skeletal muscle. However, walking exercise increases lower extremity ischemia in people with PAD, and therefore, mechanisms by which this exercise improves walking may differ between people with and without PAD. Compared with people without PAD, gastrocnemius muscle in people with PAD has greater mitochondrial impairment, increased reactive oxygen species, and increased fibrosis. In multiple small trials, walking exercise therapy did not consistently improve mitochondrial activity in people with PAD. In one 12-week randomized trial of people with PAD randomized to supervised exercise or control, supervised treadmill exercise increased treadmill walking time from 9.3 to 15.1 minutes, but simultaneously increased the proportion of angular muscle fibers, consistent with muscle denervation (from 7.6% to 15.6%), while angular myofibers did not change in the control group (from 9.1% to 9.1%). These findings suggest an adaptive response to exercise in PAD that includes denervation and reinnervation, an adaptive process observed in skeletal muscle of people without PAD during aging. Small studies have not shown significant effects of exercise on increased capillary density in lower extremity skeletal muscle of participants with PAD, and there are no data showing that exercise improves microcirculatory delivery of oxygen and nutrients in patients with PAD. However, the effects of supervised exercise on increased plasma nitrite abundance after a treadmill walking test in people with PAD may be associated with improved lower extremity skeletal muscle perfusion and may contribute to improved walking performance in response to exercise in people with PAD. Randomized trials with serial, comprehensive measures of muscle biology, and physiology are needed to clarify mechanisms by which walking exercise interventions improve mobility in PAD.

Perceived Versus Objective Change in Walking Ability in Peripheral Artery Disease: Results from 3 Randomized Clinical Trials of Exercise Therapy

Background

In people with lower‐extremity peripheral artery disease, the effects of exercise on patient‐reported outcomes remain unclear.

Methods and Results

Four hundred four people with peripheral artery disease in 3 clinical trials were randomized to exercise (N=205) or a control group (N=199) and completed the 6‐minute walk and the Walking Impairment Questionnaire distance score (score 0–100, 100=best) at baseline and 6‐month follow‐up. Compared with the control group, exercise improved 6‐minute walk distance by +39.8 m (95% CI, 26.8–52.8, P<0.001) and the Walking Impairment Questionnaire distance score by +7.3 (95% CI, 2.4–12.1, P=0.003). In all, 2828 individual Walking Impairment Questionnaire distance score questions were completed at baseline and follow‐up. Among participants who perceived no change in ability to walk 1 or more distances between baseline and follow‐up, 6‐minute walk improved in the exercise group and declined in the control group (+26.8 versus −6.5 m, P<0.001). Among participants who perceived that their walking ability worsened for 1 or more distances between baseline and follow‐up, the 6‐minute walk improved in the exercise group and declined in the control group (+18.4 versus –27.3 m, P<0.001). Among participants who reported worsening calf symptoms at follow‐up, the exercise group improved and the control group declined (+28.9 versus −12.5 m, P<0.01).

Conclusions

In 3 randomized trials, exercise significantly improved the 6‐minute walk distance in people with peripheral artery disease, but many participants randomized to exercise reported no change or decline in walking ability. These findings suggest a significant discrepancy in objectively measured walking improvement relative to perceived walking improvement in people with peripheral artery disease.

Registration Information

clinicaltrials.gov. Identifiers: NCT 00106327, NCT 01408901.

An Updated Systematic Review and Meta-Analysis of Home-based Exercise Programmes for Individuals with Intermittent Claudication

OBJECTIVES

Supervised exercise programmes (SEP) are effective for improving walking distance in patients with intermittent claudication (IC) but provision and uptake rates are sub-optimal. Access to such programmes has also been halted by the Coronavirus pandemic. The aim of this review is to provide a comprehensive overview of the evidence for home-based exercise programmes (HEP).

DATA SOURCES

Medline, EMBASE, CINAHL, PEDro and Cochrane CENTRAL were searched for terms relating to HEP and IC.

REVIEW METHODS

This review was conducted in according with the published protocol and PRISMA guidance. Randomised and non-randomised trials that compared a HEP to SEP, basic exercise advice or no exercise controls for IC were included. A narrative synthesis was provided for all studies and meta-analyses conducted using data from randomised trials. The primary outcome was maximal walking distance. Sub-group analyses were performed to consider the effect of monitoring. Risk of bias was assessed using the Cochrane tool and quality of evidence via GRADE.

RESULTS

23 studies with 1907 participants were included. Considering the narrative review, HEPs were inferior to SEPs which was reflected in the meta-analysis (MD 139m, 95% CI 45 to 232m, p = .004, very-low-quality evidence). Monitoring was an important component, as HEPs adopting this were equivalent to SEPs (MD: 8m, 95% CI -81 to 97, p = .86; moderate-quality evidence). For HEPs versus basic exercise advice, narrative review suggested HEPs can be superior, though not always significantly so. For HEPs versus no exercise controls, narrative review and meta-analysis suggested HEPs were potentially superior (MD: 136m, -2-273m p = .05, very-low-quality evidence). Monitoring was also a key element in these comparisons.Other elements such as appropriate frequency (≥3x a week), intensity (to moderate-maximum pain), duration (20 progressing to 60 minutes) and type (walking) of exercise were important, as was education, self-regulation, goal setting, feedback and action planning.

CONCLUSION

When SEPs are unavailable, HEPs are recommended. However, to elicit maximum benefit they should be structured, incorporating all elements of our evidence-based recommendations.

PROSPERO REGISTRATION NUMBER

CRD42018091248.

Lower Extremity Peripheral Artery Disease Without Chronic Limb-Threatening Ischemia: A Review

IMPORTANCE

Lower extremity peripheral artery disease (PAD) affects approximately 8.5 million people in the US and approximately 230 million worldwide.

OBSERVATIONS

Peripheral artery disease is uncommon before aged 50 years but affects up to 20% of people aged 80 years and older. It can be noninvasively diagnosed with the ankle-brachial index (ABI), a ratio of Doppler-recorded pressures in the dorsalis pedis and/or posterior tibial artery in each leg to brachial artery pressures. An ABI value less than 0.90 is 57% to 79% sensitive and 83% to 99% specific for arterial stenosis of at least 50%. Intermittent claudication, consisting of exertional calf pain that does not begin at rest and that resolves within 10 minutes of rest, is considered the classic symptom of PAD. However, 70% to 90% of people with an ABI value less than 0.90 either report no exertional leg symptoms (ie, asymptomatic) or report leg symptoms with walking that are not consistent with classic claudication. Over time, people with PAD restrict walking activity or slow walking speed to avoid leg symptoms. Thus, although approximately 75% of people with PAD report no change in leg symptoms over time, those with PAD have significantly greater annual declines in 6-minute walk performance compared with those without it. Approximately 11% of people with PAD develop chronic limb-threatening ischemia, the most severe form of PAD. Compared with people without PAD, those with the disease have approximately twice the rate of all-cause mortality, cardiovascular mortality, and major coronary events at 10-year follow-up. High-dose statins and antiplatelet therapy with or without antithrombotic therapy reduced rates of coronary events and stroke in people with PAD. Supervised treadmill exercise improved 6-minute walk distance by 30 to 35 m, consistent with a clinically meaningful change, whereas effective home-based walking exercise interventions improved 6-minute walk by 42 to 53 m. Effective home-based exercise programs require behavioral methods, including monitoring by a coach.

CONCLUSIONS AND RELEVANCE

Peripheral artery disease affects approximately 230 million people worldwide and is associated with increased rates of cardiovascular events, lower extremity events, and functional decline compared with that of people without PAD. People with PAD should be treated with the highest dose of statin tolerated, antithrombotic and/or antiplatelet therapy, and exercise.

Effectiveness of Home-Based Pain-Free Exercise versus Walking Advice in Patients with Peripheral Artery Disease: A Randomized Controlled Trial

Exercise therapy in the intermediate stages of peripheral artery disease (PAD) represents an effective solution to improve mobility and quality of life (QoL). Home-based programs, although less effective than supervised programs, have been found to be successful when conducted at high intensity by walking near maximal pain. In this randomized trial, we aim to compare a low-intensity, pain-free structured home-based exercise (SHB) program to an active control group that will be advised to walk according to guidelines. Sixty PAD patients aged > 60 years with claudication will be randomized with a 1:1 ratio to SHB or Control. Patients in the training group will be prescribed an interval walking program at controlled speed to be performed at home; the speed will be increased weekly. At baseline and after 6 months, the following outcomes will be collected: pain-free walking distance and 6-min walking distance (primary outcome), ankle-brachial index, QoL by the VascuQoL-6 questionnaire, foot temperature by thermal camera, 5-time sit-to-stand test, and long-term clinical outcomes including revascularization rate and mortality. The home-based pain-free exercise program may represent a sustainable and cost effective option for patients and health services. The trial has been approved by the CE-AVEC Ethics Committee (898/20). Registration details: Clinicaltrials.gov NCT04751890 [Registered: 12 February 2021].

Effect of Low-Intensity vs High-Intensity Home-Based Walking Exercise on Walk Distance in Patients With Peripheral Artery Disease: The LITE Randomized Clinical Trial

IMPORTANCE

Supervised high-intensity walking exercise that induces ischemic leg symptoms is the first-line therapy for people with lower-extremity peripheral artery disease (PAD), but adherence is poor.

OBJECTIVE

To determine whether low-intensity home-based walking exercise at a comfortable pace significantly improves walking ability in people with PAD vs high-intensity home-based walking exercise that induces ischemic leg symptoms and vs a nonexercise control.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter randomized clinical trial conducted at 4 US centers and including 305 participants. Enrollment occurred between September 25, 2015, and December 11, 2019; final follow-up was October 7, 2020.

INTERVENTIONS

Participants with PAD were randomized to low-intensity walking exercise (n = 116), high-intensity walking exercise (n = 124), or nonexercise control (n = 65) for 12 months. Both exercise groups were asked to walk for exercise in an unsupervised setting 5 times per week for up to 50 minutes per session wearing an accelerometer to document exercise intensity and time. The low-intensity group walked at a pace without ischemic leg symptoms. The high-intensity group walked at a pace eliciting moderate to severe ischemic leg symptoms. Accelerometer data were viewable to a coach who telephoned participants weekly for 12 months and helped them adhere to their prescribed exercise. The nonexercise control group received weekly educational telephone calls for 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was mean change in 6-minute walk distance at 12 months (minimum clinically important difference, 8-20 m).

RESULTS

Among 305 randomized patients (mean age, 69.3 [SD, 9.5] years, 146 [47.9%] women, 181 [59.3%] Black patients), 250 (82%) completed 12-month follow-up. The 6-minute walk distance changed from 332.1 m at baseline to 327.5 m at 12-month follow-up in the low-intensity exercise group (within-group mean change, -6.4 m [95% CI, -21.5 to 8.8 m]; P = .34) and from 338.1 m to 371.2 m in the high-intensity exercise group (within-group mean change, 34.5 m [95% CI, 20.1 to 48.9 m]; P < .001) and the mean change for the between-group comparison was -40.9 m (97.5% CI, -61.7 to -20.0 m; P < .001). The 6-minute walk distance changed from 328.1 m at baseline to 317.5 m at 12-month follow-up in the nonexercise control group (within-group mean change, -15.1 m [95% CI, -35.8 to 5.7 m]; P = .10), which was not significantly different from the change in the low-intensity exercise group (between-group mean change, 8.7 m [97.5% CI, -17.0 to 34.4 m]; P = .44). Of 184 serious adverse events, the event rate per participant was 0.64 in the low-intensity group, 0.65 in the high-intensity group, and 0.46 in the nonexercise control group. One serious adverse event in each exercise group was related to study participation.

CONCLUSIONS AND RELEVANCE

Among patients with PAD, low-intensity home-based exercise was significantly less effective than high-intensity home-based exercise and was not significantly different from the nonexercise control for improving 6-minute walk distance. These results do not support the use of low-intensity home-based walking exercise for improving objectively measured walking performance in patients with PAD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02538900.

Association between Physical Activity and Mortality in Patients with Claudication

PURPOSE

This study aimed to determine the association between light-intensity physical activity and the incidence of all-cause and cardiovascular mortality in patients with peripheral artery disease (PAD) limited by claudication followed for up to 18.7 yr.

METHODS

A total of 528 patients with PAD and claudication were screened in Baltimore between 1994 and 2002, and 386 were deemed eligible for the study. At baseline, patients were classified into three physical activity groups: 1) physically sedentary, 2) light intensity, and 3) moderate to vigorous intensity based on a questionnaire. All-cause and cardiovascular mortality of patients through December 2014 was determined using the National Death Index and the U.S. Department of Veterans Affairs and the U.S. Department of Defense Suicide Data Repository.

RESULTS

Median survival time was 9.9 yr (interquartile range, 4.9-15.7 yr; range, 0.38-18.7 yr). During follow-up, 257 patients (66.6%) died, consisting of 40/48 (83.3%) from the sedentary group, 135/210 (64.3%) from the light-intensity group, and 82/128 (64.0%) from the moderate- to vigorous-intensity group. For all-cause mortality, light-intensity activity status (hazard ratio [HR] = 0.523, P = 0.0007) and moderate- to vigorous-intensity status (HR = 0.425, P < 0.0001) were significant predictors. During follow-up, 125 patients died because of cardiovascular causes (32.4%), in which light-intensity activity status (HR = 0.511, P = 0.0113) and moderate- to vigorous-intensity activity status (HR = 0.341, P = 0.0003) were significant predictors.

CONCLUSIONS

Light-intensity physical activity is associated with nearly 50% lower risk of all-cause and cardiovascular mortality in high-risk patients with PAD and claudication. Furthermore, moderate- to vigorous-intensity physical activity performed regularly is associated with 58% and 66% lower risk of all-cause and cardiovascular mortality, respectively. The survival benefits associated with light-intensity physical activity make it a compelling behavioral intervention that extends beyond improving ambulation.

The Safety of Paclitaxel-Coated Devices for Patients with Peripheral Artery Disease

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is a common, debilitating disease that impacts 8.5 million Americans and carries a poor prognosis. The most common manifestation of lower extremity PAD is claudication-a condition which significantly reduces quality of life and functional status. Paclitaxel-coated balloons and stents (PCBs and PESs) represented a breakthrough in the ability to treat medication-refractory patients relative to bare metal stents (BMSs) and percutaneous transluminal angioplasty (PTA) because they improve primary patency rates, reduce target lesion revascularization (TLR), and minimize late-lumen loss for femoropopliteal lesions. As a result, paclitaxel-coated devices (PCDs) were swiftly established as the standard of care for revascularization of femoropopliteal artery disease. A recent meta-analysis of summary-level data demonstrated a late mortality signal for patients treated with paclitaxel-coated devices relative to uncoated devices. This has had a major impact on the vascular community and for the treatment of patients with PAD. Herein, we provide a detailed review of the available data on the late mortality signal associated with paclitaxel.

RECENT FINDINGS

In December of 2018, Katsanos et al. J Am Heart Assoc 7: e011245, 2018) published data from randomized-controlled trials (RCTs) that demonstrated an increase in mortality at 2 and 5 years in patients treated with PCDs involving the femoropopliteal arterial segment relative to patients treated with uncoated devices. As a result of this analysis, randomized trials were stopped and the FDA sent a letter to healthcare providers recommending restriction of use of these devices to patients at the highest risk of restenosis. As additional data emerged supporting the safety of these devices, the FDA organized an advisory committee meeting to review the available data and to determine a pathway forward. The FDA concluded that there were insufficient data to make a final decision regarding the safety of PCDs. They allowed these devices to remain on the market, but with revised safety labeling and updated their letter to healthcare providers to continue to restrict use to patients at highest risk of reintervention. The FDA also called for additional long-term data, including from RCTs and real-world data. To date, an updated patient-level meta-analysis of clinical trial data, RCTs with longer-term follow-up, and large observational studies have been conducted. While meta-analyses conducted using overlapping clinical trial data have found a persistent increase in mortality for those treated with PCDs, individual industry-sponsored RCTs and large observational studies have consistently failed to detect a corresponding mortality increase. To date, no mechanism linking paclitaxel to mortality has been observed. We are currently at an impasse for drawing definitive conclusions regarding the long-term safety of paclitaxel-coated devices. As we await enrollment in ongoing clinical trials, we must proceed with making reasonable decisions for our patients' care from the available data, as these devices have important clinical implications for our patients. A critical lesson that can be learned from this controversy is that, for future device trials, committing to long-term follow-up is crucial.

Use of the walking impairment questionnaire as a measure of functional assessment

Background: A significant consequence of peripheral arterial disease (PAD) is an impaired functional capacity and deteriorated quality of life. Therefore, our study aimed to investigate the usefulness of a symptom questionnaire and walk tests for the determination of the functional capacity of patients with intermittent claudication. Patients and methods: The study included 53 patients (38 males) with stable claudication distance (50-300m). A detailed history and physical examination, ankle-brachial index (ABI), treadmill exercise test, and 6-minute walk test were performed and compared to walking impairment questionnaire (WIQ). Results: Claudication distance reported from patients' history and 6-minute walk test were significantly correlated with ABI (p=0.033, p=0.044). There were no significant correlations between ABI and treadmill walk test or WIQ. Results of WIQ were significantly correlated with the history and the most of performed walk tests: treadmill initial and maximal claudication distance (p=0.004 and 0.012, respectively) and 6-minute walk test (p=0.026). 6-minute walk test was correlated with maximal claudication distance of treadmill (p=0.018), but not with an initial claudication distance. Conclusions: The validity of WIQ is comparable to walk tests and represents the useful technique for the investigation of the functional capacity of patients with PAD. A self-report based on WIQ enables a longer period of observation. It should be routinely used as a basic diagnostic tool for the estimation of the functional capacity of PAD patients with stable intermittent claudication.

Walking for hypertension

BACKGROUND

Increased physical activity has been recommended as an important lifestyle modification for the prevention and control of hypertension. Walking is a low-cost form of physical activity and one which most people can do. Studies testing the effect of walking on blood pressure have revealed inconsistent findings.

OBJECTIVES

To determine the effect of walking as a physical activity intervention on blood pressure and heart rate.

SEARCH METHODS

We searched the following databases up to March 2020: the Cochrane Hypertension Specialised Register, CENTRAL (2020, Issue 2), Ovid MEDLINE, Ovid Embase, CINAHL, PsycINFO, SPORTDiscus, PEDro, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also searched the following Chinese databases up to May 2020: Index to Taiwan Periodical Literature System; National Digital Library of Theses and Dissertation in Taiwan; China National Knowledge Infrastructure (CNKI) Journals, Theses & Dissertations; and Wanfang Medical Online. We contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials of participants, aged 16 years and over, which evaluated the effects of a walking intervention compared to non-intervention control on blood pressure and heart rate were included.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Where data were not available in the published reports, we contacted authors. Pooled results for blood pressure and heart rate were presented as mean differences (MDs) between groups with 95% confidence intervals (CIs). We undertook subgroup analyses for age and sex. We undertook sensitivity analyses to assess the effect of sample size on our findings.

MAIN RESULTS

A total of 73 trials met our inclusion criteria. These 73 trials included 5763 participants and were undertaken in 22 countries. Participants were aged from 16 to 84 years and there were approximately 1.5 times as many females as males. The characteristics of walking interventions in the included studies were as follows: the majority of walking interventions was at home/community (n = 50) but supervised (n = 36 out of 47 reported the information of supervision); the average intervention length was 15 weeks, average walking time per week was 153 minutes and the majority of walking intensity was moderate. Many studies were at risk of selection bias and performance bias. Primary outcome We found moderate-certainty evidence suggesting that walking reduces systolic blood pressure (SBP) (MD -4.11 mmHg, 95% CI -5.22 to -3.01; 73 studies, n = 5060). We found moderate-certainty evidence suggesting that walking reduces SBP in participants aged 40 years and under (MD -4.41 mmHg, 95% CI -6.17 to -2.65; 14 studies, n = 491), and low-certainty evidence that walking reduces SBP in participants aged 41 to 60 years (MD -3.79 mmHg, 95% CI -5.64 to -1.94, P < 0.001; 35 studies, n = 1959), and those aged 60 years of over (MD -4.30 mmHg, 95% CI -6.17 to -2.44, 24 studies, n = 2610). We also found low certainty-evidence suggesting that walking reduces SBP in both females (MD -5.65 mmHg, 95% CI -7.89 to -3.41; 22 studies, n = 1149) and males (MD -4.64 mmHg, 95% CI -8.69 to -0.59; 6 studies, n = 203). Secondary outcomes We found low-certainty evidence suggesting that walking reduces diastolic blood pressure (DBP) (MD -1.79 mmHg, 95% CI -2.51 to -1.07; 69 studies, n = 4711) and heart rate (MD -2.76 beats per minute (bpm), 95% CI -4.57 to -0.95; 26 studies, n = 1747). We found moderate-certainty evidence suggesting that walking reduces DBP for participants aged 40 years and under (MD -3.01 mmHg, 95% CI -4.44 to -1.58; 14 studies, n = 491) and low-certainty evidence suggesting that walking reduces DBP for participants aged 41 to 60 years (MD -1.74 mmHg, 95% CI -2.95 to -0.52; 32 studies, n = 1730) and those aged 60 years and over (MD -1.33 mmHg, 95% CI -2.40 to -0.26; 23 studies, n = 2490). We found moderate-certainty evidence that suggests walking reduces DBP for males (MD -2.54 mmHg, 95% CI -4.84 to -0.24; 6 studies, n = 203) and low-certainty evidence that walking reduces DBP for females (MD -2.69 mmHg, 95% CI -4.16 to -1.23; 20 studies, n = 1000). Only 21 included studies reported adverse events. Of these 21 studies, 16 reported no adverse events, the remaining five studies reported eight adverse events, with knee injury being reported five times.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that walking probably reduces SBP. Moderate- or low-certainty evidence suggests that walking may reduce SBP for all ages and both sexes. Low-certainty evidence suggests that walking may reduce DBP and heart rate. Moderate- and low-certainty evidence suggests walking may reduce DBP and heart rate for all ages and both sexes.

Effect of Home-based Exercise Therapy for Peripheral Arterial Disease Patients Underwent Endovascular Treatment: A Clinical Controlled Design

OBJECTIVE

This study aimed to clarify the effect of home-based exercise therapy on physical activity in peripheral arterial disease (PAD) patients after EVT.

METHODS

Study design was controlled clinical design. The subjects were 30 patients (76.6% men) who underwent EVT in the Sakakibara Heart Institute of Okayama. Patients with EVT meeting the inclusion criteria were divided into two groups, intervention group (Home-based exercise) and control group. Patients' basic characteristics, the number of steps walked and QOL questionnaire (WIQ, SEPA, Vascu QOL) were assessed before surgery and, at the 3 month after discharge. A two-way analysis of variance (ANOVA) was performed to compare number of steps walked and QOL questionnaire.

RESULTS

Interaction effect were observed in the number of steps walked (F (1,28) =13.89, p<0.01). A multiple comparison test confirmed a significant increase between results of before surgery and at three months after surgery in the intervention group (p<0.01). An interaction between the presence and absence of intervention was found for the WIQ pain score (F(1,28) = 5.86, p=0.01), speed score (F(1,28) = 3.80, p=0.04) and SEPA (F(1,28) = 4.99, p=0.03). In a multiple comparison study, there was a significant increase in WIQ pain and speed scores in both groups before and 3 months after discharge from the hospital.

CONCLUSION

Home-based exercise therapy using physical activity indices has the potential to improve number of steps and quality of life in patients with PAD after EVT.

Exercise Training and Revascularization in the Management of Symptomatic Peripheral Artery Disease

•

In the management of symptomatic peripheral artery disease, aerobic exercise therapy and lower extremity revascularization are the mainstays of therapy.

•

In this structured review, the most effective therapies, with 6 to 18 months of follow-up, indicated that exercise therapy and lower extremity revascularization each independently improve peak walking performance.

•

The combination of therapies was superior to either therapy alone and may decrease the need for subsequent revascularization.

•

Further research is needed to evaluate the long-term durability of these interventions, their impacts on subsequent invasive procedures, and predictors of response.

Exercise therapy and lower extremity revascularization both improve walking performance in symptomatic patients with peripheral artery disease. The combination of therapies provides greater benefit than either alone and may reduce the need for subsequent revascularization procedures, but further trials with longer follow-up are needed for the outcome of subsequent revascularization.

Clinical characteristics and response to supervised exercise therapy of people with lower extremity peripheral artery disease

BACKGROUND

Among people with lower extremity peripheral artery disease (PAD), little is known about variation in response to supervised exercise therapy (SET). Clinical characteristics associated with greater responsiveness to SET have not been identified.

METHODS

Data from participants with PAD in two randomized clinical trials comparing SET vs nonexercising control were combined. The exercise intervention consisted of three times weekly supervised treadmill exercise. The control groups received lectures on health-related topics.

RESULTS

Of 309 unique participants randomized (mean age, 67.9 years [standard deviation, 9.3 years]; 132 [42.7%] women; 185 [59.9%] black), 285 (92%) completed 6-month follow-up. Compared with control, those randomized to SET improved 6-minute walk distance by 35.6 meters (95% confidence interval, 21.4-49.8; P < .001). In the 95 (62.1%) participants who attended at least 70% of SET sessions, change in 6-minute walk distance varied from -149.4 to +356.0 meters. Thirty-four (35.8%) had no 6-minute walk distance improvement. Among all participants, age, sex, race, body mass index, prior lower extremity revascularization, and other clinical characteristics did not affect the degree of improvement in 6-minute walk distance after SET relative to the control group. Participants with 6-minute walk distance less than the median of 334 meters at baseline had greater percentage improvement in 6-minute walk distance compared with those with baseline 6-minute walk distance above the median (+20.5% vs +5.3%; P for interaction = .0107).

CONCLUSIONS

Among people with PAD, substantial variability exists in walking improvement after SET. Shorter 6-minute walk distance at baseline was associated with greater improvement after SET, but other clinical characteristics, including age, sex, prior lower extremity revascularization, and disease severity, did not affect responsiveness to exercise therapy.

Automated Detection of Exercise Sessions in Patients With Peripheral Artery Disease: EVIDENCE FOR AN EXERCISE DOSE RESPONSE TO TRAINING

PURPOSE

Monitoring home exercise using accelerometry in patients with peripheral artery disease (PAD) may provide a tool to improve adherence and titration of the exercise prescription. However, methods for unbiased analysis of accelerometer data are lacking. The aim of the current post hoc analysis was to develop an automated method to analyze accelerometry output collected during home-based exercise.

METHODS

Data were obtained from 54 patients with PAD enrolled in a clinical trial that included a home-based exercise intervention using diaries and an accelerometer. Peak walking time was assessed on a graded treadmill at baseline and 6 mo. In 35 randomly selected patient data sets, visual inspection of accelerometer output confirmed exercise sessions throughout the 6 mo. An algorithm was developed to detect exercise sessions and then compared with visual inspection of sessions to mitigate the heterogeneity in session intensity across the population. Identified exercise sessions were characterized on the basis of total step count and activity duration. The methodology was then applied to data sets for all 54 patients.

RESULTS

The ability of the algorithm to detect exercise sessions compared with visual inspection of the accelerometer output resulted in a sensitivity of 85% and specificity of 90%. Algorithm-detected exercise sessions (total) and intensity (steps/wk) were correlated with change in peak walking time (r = 0.28; r = 0.43).

CONCLUSIONS

An algorithm to assess data from an accelerometer successfully detected home-based exercise sessions. Algorithm-identified exercise sessions were correlated with improvements in performance after 6 mo of training in patients with PAD, supporting the effectiveness of monitored home-based exercise.

Exercise training for intermittent claudication: a narrative review and summary of guidelines for practitioners

Peripheral artery disease (PAD) is caused by atherosclerotic narrowing of the arteries supplying the lower limbs often resulting in intermittent claudication, evident as pain or cramping while walking. Supervised exercise training elicits clinically meaningful benefits in walking ability and quality of life. Walking is the modality of exercise with the strongest evidence and is recommended in several national and international guidelines. Alternate forms of exercise such as upper- or lower-body cycling may be used, if required by certain patients, although there is less evidence for these types of programmes. The evidence for progressive resistance training is growing and patients can also engage in strength-based training alongside a walking programme. For those unable to attend a supervised class (strongest evidence), home-based or 'self-facilitated' exercise programmes are known to improve walking distance when compared to simple advice. All exercise programmes, independent of the mode of delivery, should be progressive and individually prescribed where possible, considering disease severity, comorbidities and initial exercise capacity. All patients should aim to accumulate at least 30 min of aerobic activity, at least three times a week, for at least 3 months, ideally in the form of walking exercise to near-maximal claudication pain.

Promoting Active Aging: Lessons Learned in an Implementation Pilot in Primary Care

BACKGROUND

Physical activity (PA) preserves mobility, but few practices screen older adults for mobility impairment or counsel on PA.

DESIGN

"Promoting Active Aging" (PAA) was a mixed-methods randomized-controlled pilot, to test the feasibility and acceptability of a video-based PA counseling tool and implementation into practice of two mobility assessment tools.

SETTING

Three primary care practices affiliated with Wake Forest Baptist Health.

PARTICIPANTS

Adults aged 65 years and older who presented for primary care follow-up and were willing and able to answer self-report questions and walk 4 meters (n = 59).

INTERVENTION

Video-based PA counseling intervention versus control video, "Healthy Eating."

MEASUREMENTS

Potential participants completed mobility assessments: self-report (Mobility Assessment Tool-short form (MAT-sf)) and performance based (4-meter walk test). We assessed PAA's implementation-feasibility, acceptability, and value-via interviews and surveys. Effectiveness was measured via participant attendance at a PA information session.

RESULTS

Of 92 patients approached, 89 (96.7%) agreed to mobility assessment. Eighty-nine completed MAT-sf, and 97.8% (87/89) completed 4-meter walk test. Sixty-seven (75%) met eligibility criteria, and 59 (88%) consented to be randomized either to the PA counseling intervention (Video-PA) or to active control (Video-C). Most participants viewed the walk test positively (51/59; 86.4%). Staff reported that completion of patient surveys, MAT-sf, and videos required significant staff time and support (median = 26 minutes for all), resulting in low acceptability of MAT-sf and the videos. Attendance at a PA information session did not differ by randomization group (Video-PA = 11/29 (37.9%); Video-C = 12/30 (40%); 95% confidence interval for difference in proportion = -0.29 to 0.25).

CONCLUSIONS

Mobility assessment, particularly a 4-meter walk test, was feasible in primary care. Tablet-based assessment (MAT-sf) and video counseling tools, selected to reduce staff effort, instead required significant time to implement. Future work to promote PA should identify effective ways to facilitate adoption of PA in sedentary older adults that do not burden staff.

Biobehavioral Intervention Targeting Physical Activity Behavior Change for Older Veterans after Nontraumatic Amputation: A Randomized Controlled Trial

BACKGROUND

Lower-limb amputation (LLA) due to non-traumatic vascular etiology is linked to extremely low physical activity and high disability.

OBJECTIVE

To test the feasibility of a biobehavioral intervention designed to promote physical activity.

DESIGN

A randomized, single-blind feasibility trial with a crossover design.

SETTING

Veterans Administration Medical Center.

PARTICIPANTS

Military veterans (age: 65.7 [7.8] years; mean [standard deviation]) with nontraumatic lower-limb amputation (LLA), randomized to two groups: GROUP1 (n = 16) and GROUP2 (n = 15). Both groups had similar baseline amputation characteristics (level of amputation and time since amputation).

INTERVENTIONS

Twelve weekly, 30-minute telehealth sessions of physical activity behavior-change intervention, with GROUP1 participating in weeks 1-12 and GROUP2 in weeks 13-24. GROUP1 noncontact phase in weeks 13-24 and GROUP2 attention control telehealth phase in weeks 1-12.

MAIN OUTCOME MEASURES

Feasibility (participant retention, dose goal attainment, intervention acceptability [Intrinsic Motivation Inventory [IMI] Interest and Enjoyment scale], safety) and signal of efficacy (free-living physical activity [accelerometer-based average daily step count], Late Life Function and Disability Index - Disability Scale [LLFDI-DS]).

RESULTS

Participant retention rate was high (90%), with three participants lost to follow-up during the intervention period. Dose goal attainment was low, with only 10% of participants achieving an a priori walking dose goal. Intervention was rated as acceptable, with mean IMI Interest and Enjoyment score (5.8) statistically higher than the null value of 5.0 (P = .002). There were no between-group differences in adverse event rates (falls: P = .19, lower extremity wounds: P = .60). There was no signal of efficacy for change in average daily step count (d = -0.15) or LLFDI-DS (d = -0.22 and 0.17 for frequency and limitations scales, respectively).

CONCLUSIONS

Telehealth delivered biobehavioral intervention resulted in acceptable participant retention, low dose goal attainment, high participant acceptability, and low safety risk, while having no signal of efficacy (physical activity, disability) for people with nontraumatic LLA.

Telephone health coaching with exercise monitoring using wearable activity trackers (TeGeCoach) for improving walking impairment in peripheral artery disease: study protocol for a randomised controlled trial and economic evaluation

INTRODUCTION

Peripheral artery disease (PAD) is the third most prevalent cardiovascular disease worldwide, with smoking and diabetes being the strongest risk factors. The most prominent symptom is leg pain while walking, known as intermittent claudication. To improve mobility, first-line treatment for intermittent claudication is supervised exercise programmes, but these remain largely unavailable and economically impractical, which has led to the development of structured home-based exercise programmes. This trial aims to determine the effectiveness and cost advantage of TeGeCoach, a 12-month long home-based exercise programme, compared with usual care of PAD. It is hypothesised that TeGeCoach improves walking impairment and lowers the need of health care resources that are spent on patients with PAD.

METHODS AND ANALYSIS

The investigators conduct a prospective, pragmatic randomised controlled clinical trial in a health insurance setting. 1760 patients diagnosed with PAD at Fontaine stage II are randomly assigned to either TeGeCoach or care-as-usual. TeGeCoach consists of telemonitored intermittent walking exercise with medical supervision by a physician and telephone health coaching. Participants allocated to the usual care group receive information leaflets and can access supervised exercise programmes, physical therapy and a variety of programmes for promoting a healthy lifestyle. The primary outcome is patient reported walking ability based on the Walking Impairment Questionnaire. Secondary outcome measures include quality of life, health literacy and health behaviour. Claims data are used to collect total health care costs, healthcare resource use and (severe) adverse events. Outcomes are measured at baseline, 12 and 24 months.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Medical Association Hamburg. Findings are disseminated through peer-reviewed journals, reports to the funding body, conference presentations and media press releases. Data from this trial are made available to the public and researchers upon reasonable request.NCT03496948 (www.clinicaltrials.gov), Pre-results.

Rationale and design of a smartphone-enabled, home-based exercise program in patients with symptomatic peripheral arterial disease: The smart step randomized trial

BACKGROUND

Supervised exercise therapy (SET) is recommended in patients with symptomatic peripheral arterial disease (PAD) as first-line therapy, although patient adoption remains low. Home-based exercise therapy (HBET) delivered through smartphones may expand access. The feasibility of such programs, especially in low-resource settings, remains unknown.

METHODS

Smart Step is a pilot randomized trial of smartphone-enabled HBET vs walking advice in patients with symptomatic PAD in an inner-city hospital. Participants receive a smartphone app with daily exercise reminders and educational content. A trained coach performs weekly phone-based coaching sessions. All participants receive a Fitbit Charge HR 2 to measure physical activity. The primary outcome changes in 6-minute walking test (6MWT) distance at 12 weeks over baseline. Secondary outcomes are the degree of engagement with the smartphone app and changes in health behaviors and quality of life scores after 12 weeks and 1 year.

RESULTS

A total of 15 patients are randomized as of December 15, 2019 with a mean (SD) age of 66.1 (5.8) years. The majority are female (60%) and black (87%). At baseline, the mean (SD) ABI and 6MWT were 0.86 (0.29) and 363.5 m, respectively. Enrollment is expected to continue until December 2020 to achieve a target size of 50 participants.

CONCLUSIONS

The potential significance of this trial will be to provide preliminary evidence of a home-based, "mobile-first" approach for delivering a structured exercise rehabilitation program. Smartphone-enabled HBET can be potentially more accessible than center-based programs, and if proven effective, may have a potential widespread public health benefit.

Polonsky T, Leeuwenburgh C, Ferrucci L, Peterson CA. Correlations of Calf Muscle Macrophage Content With Muscle Properties and Walking Performance in Peripheral Artery Disease

Background Peripheral artery disease (PAD) is a manifestation of atherosclerosis characterized by reduced blood flow to the lower extremities and mobility loss. Preliminary evidence suggests PAD damages skeletal muscle, resulting in muscle impairments that contribute to functional decline. We sought to determine whether PAD is associated with an altered macrophage profile in gastrocnemius muscles and whether muscle macrophage populations are associated with impaired muscle phenotype and walking performance in patients with PAD. Methods and Results Macrophages, satellite cells, and extracellular matrix in gastrocnemius muscles from 25 patients with PAD and 7 patients without PAD were quantified using immunohistochemistry. Among patients with PAD, both the absolute number and percentage of cluster of differentiation (CD) 11b+CD206+ M2-like macrophages positively correlated to satellite cell number (r=0.461 [P=0.023] and r=0.416 [P=0.042], respectively) but not capillary density or extracellular matrix. The number of CD11b+CD206- macrophages negatively correlated to 4-meter walk tests at normal (r=-0.447, P=0.036) and fast pace (r=-0.510, P=0.014). Extracellular matrix occupied more muscle area in PAD compared with non-PAD (8.72±2.19% versus 5.30±1.03%, P<0.001) and positively correlated with capillary density (r=0.656, P<0.001). Conclusions Among people with PAD, higher CD206+ M2-like macrophage abundance was associated with greater satellite cell numbers and muscle fiber size. Lower CD206- macrophage abundance was associated with better walking performance. Further study is needed to determine whether CD206+ macrophages are associated with ongoing reparative processes enabling skeletal muscle adaptation to damage with PAD. Registration URL: https://www.clini​caltr​ials.gov; Unique identifiers: NCT00693940, NCT01408901, NCT0224660.

Acute Lower Leg Heating Increases Exercise Capacity in Patients With Peripheral Artery Disease

BACKGROUND/OBJECTIVE

In this pilot study, we tested the hypothesis that acute lower leg heating (LLH) increases postheating popliteal artery blood flow and 6-minute walk distance in patients with peripheral artery disease (PAD).

METHODS

Six patients (5 male, 1 female) with PAD (69 ± 6.9 years; claudication: ankle-brachial index < 0.90) participated in 3 randomized treatment sessions (2-7 days apart): control or bilateral LLH conducted via water bath immersion (42°C; ~40-cm depth) for either 15 or 45 minutes. Popliteal artery blood flow (Doppler ultrasound) and arterial pressure were measured before and after LLH. Six-minute walk distance was measured on the control day and each experimental day 35 minutes post-LLH.

RESULTS

Popliteal artery blood flow increased after heating in a duration-dependent manner (P < .05, postheating vs control for both heating conditions and between them). Six-minute walk distance increased by 10% and 12% after 15- and 45-minute heating treatments, respectively (P < .05 vs control session).

CONCLUSIONS

Lower leg heating, for as short as 15 minutes, increases postheating leg perfusion and exercise capacity in patients with PAD.

Association of six-minute walk distance with subsequent lower extremity events in peripheral artery disease

The prognostic significance of the six-minute walk distance for lower extremity events in people with peripheral artery disease (PAD) is unknown. This longitudinal study assessed whether a poorer six-minute walk distance at baseline was associated with higher rates of subsequent lower extremity atherosclerotic disease events in PAD. A total of 369 patients (mean age 69.4 ± 10.0 years; mean ankle–brachial index (ABI) 0.67 ± 0.17; 31% women; 30% black individuals) from Chicago-area medical centers with PAD were enrolled. Participants underwent baseline six-minute walk testing and returned for annual study visits. Lower extremity events consisted of one or more of the following: ABI decline greater than 15% or medical record adjudicated lower extremity revascularization, critical limb ischemia, or amputation. At a mean follow-up of 33.3 months, lower extremity events occurred in 66/123 (53.7%) people in the first (worst) tertile of six-minute walk performance, 55/124 (44.4%) in the second tertile, and 56/122 (45.9%) in the third (best) tertile. After adjusting for age, sex, race, ABI, comorbidities, and other confounders, participants in the first (worst) tertile of six-minute walk distance at baseline had higher rates of lower extremity events during follow-up, compared to those in the best tertile at baseline (HR = 1.74, 95% CI 1.17–2.60, p = 0.0067). Among people with PAD, a poorer six-minute walk distance was associated with higher rates of subsequent lower extremity PAD-related events after adjusting for confounders. Further study is needed to determine whether interventions that improve six-minute walk distance can reduce lower extremity adverse events in people with PAD.

Meaningful change in 6-minute walk in people with peripheral artery disease

OBJECTIVE

The 6-minute walk test is a common outcome measure in clinical trials of people with lower extremity peripheral artery disease (PAD). However, what constitutes a meaningful change in the 6-minute walk distance has not been well defined for people with PAD. The present study related the change in the 6-minute walk distance to the degree of participant-reported improvement or decline in the 6-minute walk distance to define a meaningful change in the 6-minute walk distance for those with PAD.

METHODS

Participants with PAD from three observational longitudinal studies completed the walking impairment questionnaire (WIQ) distance score and 6-minute walk at baseline and 1 year later. The WIQ distance score measures participants' perceived difficulty walking seven different distances without stopping (ranging from walking around the home to walking 5 blocks) on a 0 to 4 Likert scale, with 0 representing an inability to walk the distance and 4 representing no difficulty. The mean changes in the 6-minute walk distance corresponding to the participants' report of no change, 1-unit change, or 2-unit change, respectively, in the Likert scale score between the baseline and 1-year follow-up measures were calculated for each WIQ distance.

RESULTS

A total of 777 participants with PAD (mean age, 71.2 ± 8.8 years; mean baseline 6-minute walk distance, 350.1 ± 118.1 meters) completed 5439 questions about their difficulty walking each WIQ distance at baseline and follow-up. Participants with PAD who reported no change in their difficulty in walking each WIQ distance between baseline and follow-up had a decline of 7.2 meters (95% confidence interval [CI], -11.6 to -2.8 meters) in the 6-minute walk test. Relative to those reporting no change in difficulty walking, the participants reporting 1- and 2-point improvements in walking ability showed 6-minute walk distance improvements of 7.8 meters (95% CI, -0.3 to 15.9 meters) and 20.1 meters (95% CI, 1.1-39.2 meters), respectively. Relative to those reporting no change in walking difficulty, those reporting 1- and 2-point declines in perceived walking difficulty showed declines of -11.2 meters (95% CI, -19.0 to -3.4 meters) and -23.8 meters (95% CI, -37.4 to -10.3 meters) in the 6-minute walk distance.

CONCLUSIONS

Among people with PAD, ∼8- and ∼20-meter improvements in the 6-minute walk distance represent small and large improvements in walking ability, respectively. People with PAD who reported no change in their ability to walk distances over 1 year simultaneously declined by a mean of 7 meters in the 6-minute walk test. These findings will be useful for interpreting the results from randomized trials of interventions to improve the walking performance of people with PAD.

Rationale and design of the granulocyte-macrophage colony stimulating factor in peripheral arterial disease (GPAD-3) study

BACKGROUND

Lower extremity peripheral arterial disease (PAD) is a public health problem and many patients with PAD experience claudication despite adequate medical and/or surgical management. Mobilization of endogenous progenitor cells using Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) is a novel therapeutic option that has shown promising results in experimental models and phase I/IIA clinical trials. The GPAD-3 trial will study the effect of two successive administrations of GM-CSF at 3-month interval for improving claudication among patients with lower extremity PAD.

METHODS

We plan to recruit 176 patients in this ongoing randomized, double-blind, placebo-controlled Phase IIB trial. After screening for inclusion and exclusion criteria, eligible subjects undergo a 4-week screening phase where they perform subcutaneous placebo injections thrice weekly and walk at least three times a day until they develop claudication. After the screening phase, eligible subjects undergo baseline testing and are randomized 2:1 to receive 500 μg/day of GM-CSF subcutaneously thrice weekly for three weeks or placebo injections. After 3 months, follow-up endpoint testing is performed and subjects in the GM-CSF group receive the second administration of the drug for three weeks while subjects in placebo group receive matching placebo injections. All participants undergo endpoint testing at six-month and nine-month follow-up. The primary endpoint is change in 6-min walk distance between baseline and 6-month follow-up.

CONCLUSION

GPAD-3 explores a novel approach to address the need for alternative therapies that can alleviate symptoms among patients with lower extremity PAD. If successful, this study will pave the way for a pivotal Phase III trial.

Effects of walking exercise on bowel preparation in patients undergoing colonoscopy: evidence from systematic review and meta-analysis

Objective

This meta-analysis aimed to evaluate the effects of walking exercise on bowel preparation in patients undergoing colonoscopy.

Methods

PubMed, Web of Science, EMBASE, Ovid, The Cochrane Library, Wanfang Data, China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, and Chinese BioMedical Database were searched from their inception to January 2019. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) examining the effects of walking exercise in patients undergoing colonoscopy were considered for inclusion. After screening literature, extracting data and evaluating methodological quality, RevMan 5.3 software was used for meta-analysis.

Results

Five studies (four RCTs and one CCTs) involved 984 participants were included. The results of meta-analysis demonstrated that the walking exercise group showed significantly higher improvements in the rate of adequate bowel preparation than the control group (risk ratio [RR] = 1.28, 95% confidence interval [CI] [1.03–1.58], P < 0.05). In addition, the walking exercise group had lower incidence of vomiting (RR = 0.39, 95% CI [0.23–0.68], P < 0.01) and abdominal pain (RR = 0.51, 95% CI [0.29–0.90], P < 0.05) with lower heterogeneity.

Conclusions

This systematic review and meta-analysis provided specific evidence that walking exercise during bowel preparation can improve the rate of adequate bowel preparation and reduce the incidence of vomiting and abdominal pain in patients undergoing colonoscopy. Since the conclusion of this meta-analysis was drawn based on the limited number of high-quality RCTs, more rigorous RCTs should be conducted in the future.

Relationships Between Profiles of Physical Activity and Major Mobility Disability in the LIFE Study

OBJECTIVES

To examine the relationship between time spent in light physical activity (LPA) and in moderate to vigorous physical activity (MVPA) and the pattern of accumulation on the risk for major mobility disability (MMD) in a large multicenter study of physical activity (PA) and aging, the Lifestyle Interventions and Independence for Elders (LIFE) study.

DESIGN

Data were collected from individuals randomized to a PA intervention as part of the LIFE study, an eight-center single-blind randomized clinical trial conducted between February 2010 and December 2013.

SETTING

Lifestyle Interventions and Independence for Elders Study PARTICIPANTS: Older adult participants (78.4 years; N = 507) at risk for MMD.

INTERVENTION

All older adults included in these analyses were randomized to a structured PA intervention that included two center-based plus three to four home-based exercise sessions per week with a primary goal of walking for 150 minutes weekly. Participants attended the intervention for 2.5 years on average.

MEASUREMENTS

MMD was defined as the inability to complete a 400-m walk within 15 minutes and without assistance. Physical function was assessed via the Short Physical Performance Battery (SPPB). Actigraph accelerometers were used to quantify amount and variability in LPA and MVPA.

RESULTS

In an adjusted Cox proportional hazards regression, we identified a significant interaction (P = .017) between SPPB score and LPA amount and variability such that more LPA was associated with a reduced risk for MMD among those with higher initial function, as was lower variability (eg, via distributing LPA across the day). The SPPB × MVPA interaction was significant (P = .04), such that more MVPA was associated with lower MMD risk among those with lower function. Finally, greater MVPA variability was associated with lower risk for MMD.

CONCLUSION

A prescription of PA for older adults should account for key factors such as physical function and emphasize both amount and pattern of accumulation of PA from across the intensity continuum. J Am Geriatr Soc 68:1476-1483, 2020.

Assessment of behavioral determinants influencing success of supervised exercise therapy in patients with intermittent claudication: A cross sectional survey

BACKGROUND

Supervised exercise therapy is the first step in treatment of intermittent claudication. However, adherence to supervised exercise therapy is low. Limited access and reimbursement issues are known reasons, though lack of motivation is often leading. Behavioral determinants influencing motivation and thus adherence to supervised exercise therapy remain to be investigated. In this study we sought to determine which behavioral determinants would be of influence on the long-term adherence of supervised exercise therapy.

METHODS

200 patients, newly diagnosed with peripheral arterial disease Rutherford classification II-III, were sent a questionnaire to assess motivation and behavior with regard to supervised exercise therapy. The questionnaire was constructed using the I-CHANGE model for explaining motivational and behavioral change. Baseline characteristics were acquired from medical records. Alpha Cronbach's was calculated to test reliability of the questionnaire.

RESULTS

108 (54%) patients returned their questionnaire. A total of 79% patients followed supervised exercise therapy. Patients who increased their walking distance after supervised exercise therapy have significantly greater knowledge (p = 0.05), positive attitude (p = 0.03) and lower negative attitude (p = 0.01). Patients with a higher self-efficacy remained significantly more active after participating in supervised exercise therapy (p = 0.05).

CONCLUSION

Increasing the determinants knowledge, attitude and self-efficacy will improve adherence to supervised exercise therapy and result in delayed claudication onset time.

Cocoa to Improve Walking Performance in Older People With Peripheral Artery Disease: The COCOA-PAD Pilot Randomized Clinical Trial

RATIONALE

Cocoa and its major flavanol component, epicatechin, have therapeutic properties that may improve limb perfusion and increase calf muscle mitochondrial activity in people with lower extremity peripheral artery disease (PAD).

OBJECTIVE

In a phase II randomized clinical trial, to assess whether 6 months of cocoa improved walking performance in people with PAD, compared with placebo.

METHODS AND RESULTS

Six-month double-blind, randomized clinical trial in which participants with PAD were randomized to either cocoa beverage versus placebo beverage. The cocoa beverage contained 15 g of cocoa and 75 mg of epicatechin daily. The identical appearing placebo contained neither cocoa nor epicatechin. The 2 primary outcomes were 6-month change in 6-minute walk distance measured 2.5 hours after a study beverage at 6-month follow-up and 24 hours after a study beverage at 6-month follow-up, respectively. A 1-sided P<0.10 was considered statistically significant. Of 44 PAD participants randomized (mean age, 72.3 years [±7.1]; mean ankle brachial index, 0.66 [±0.15]), 40 (91%) completed follow-up. Adjusting for smoking, race, and body mass index, cocoa improved 6-minute walk distance at 6-month follow-up by 42.6 m ([90% CI, +22.2 to +∞] P=0.005) at 2.5 hours after a final study beverage and by 18.0 m ([90% CI, -1.7 to +∞] P=0.12) at 24 hours after a study beverage, compared with placebo. In calf muscle biopsies, cocoa improved mitochondrial COX (cytochrome c oxidase) activity (P=0.013), increased capillary density (P=0.014), improved calf muscle perfusion (P=0.098), and reduced central nuclei (P=0.033), compared with placebo.

CONCLUSIONS

These preliminary results suggest a therapeutic effect of cocoa on walking performance in people with PAD. Further study is needed to definitively determine whether cocoa significantly improves walking performance in people with PAD.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02876887. Visual Overview: An online visual overview is available for this article.