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

Durability of Benefits From Supervised Treadmill Exercise in People With Peripheral Artery Disease

Background It is currently unknown whether 6 months of supervised treadmill exercise has a durable benefit on 6-minute walk performance, even after exercise is completed, in people with peripheral artery disease. Methods and Results A total of 156 participants with peripheral artery disease were randomized to 1 of 3 groups: supervised treadmill exercise, supervised resistance training, or attention control. Participants received supervised sessions during months 1 to 6 and telephone contact during months 6 to 12. Primary outcomes were change in 6-minute walk distance and short physical performance battery at 6-month follow-up and have been reported previously. Secondary outcomes were change in 6-minute walk and short physical performance battery at 12-month follow-up and are reported here. A group of 134 participants (86%) completed the 12-month follow-up. At 6-month follow-up, compared with control, 6-minute walk distance improved in the treadmill exercise group (+36.1 m, 95% CI =13.9-58.3, P=0.001). Between 6- and 12-month follow-up, 6-minute walk distance significantly declined (-28.6 m, 95% CI=-52.6 to -4.5, P=0.020) and physical activity declined -272 activity units (95% CI =-546 to +2, P=0.052) in the treadmill exercise group compared with controls. At 12-month follow-up, 6 months after completing supervised treadmill exercise, change in 6-minute walk distance was not different between the treadmill exercise and control groups (+7.5, 95% CI =-17.5 to +32.6, P=0.56). There were no differences in short physical performance battery change between either exercise group and control at 6-month or 12-month follow-up. Conclusions A 6-month supervised treadmill exercise intervention that improved 6-minute walk distance at 6-month follow-up did not have persistent benefit at 12-month follow-up. These results do not support a durable benefit of supervised treadmill exercise in peripheral artery disease. Clinical Trial Registration URL : https://www.clinicaltrials.gov . Identifier: NCT 00106327.

Exercise therapy in routine management of peripheral arterial disease and intermittent claudication: a scoping review

BACKGROUND

Little is known about the extent to which routine care management of peripheral arterial disease (PAD) and intermittent claudication (IC) align with best practice recommendations on exercise therapy. We conducted a scoping review to examine the published literature on the availability and workings of exercise therapy in the routine management of patients with PAD and IC, and the attitude and practice of health professionals and patients.

METHODS

A systematic search was conducted in February 2018. The Cumulative Index of Nursing and Allied Health Literature, Ovid MEDLINE, Allied and Complementary Medicine Database, ScienceDirect, Web of Science and the Directory of Open Access Repositories were searched. Hand searching of reference lists of identified studies was also performed. Inclusion criteria were based on study aim, and included studies that reported on the perceptions, practices, and workings of routine exercise programs for patients with IC, their availability, access, and perceived barriers.

RESULTS

Eight studies met the eligibility criteria and were included in the review. Studies conducted within Europe were included. Findings indicated that vascular surgeons in parts of Europe generally recognize supervised exercise therapy as a best practice treatment for IC, but do not often refer their patients for supervised exercise therapy due to the unavailability of, or lack of access to supervised exercise therapy programs. Available supervised exercise therapy programs do not implement best practice recommendations, and in the majority, patients only undergo one session per week. Some challenges were cited as the cause of the suboptimal program implementation. These included issues related to patients' engagement and adherence as well as resource constraints.

CONCLUSION

There is a dearth of published research on exercise therapy in the routine management of PAD and IC. Available data from a few countries within Europe indicated that supervised exercise is underutilized despite health professionals recognizing the benefits. Research is needed to understand how to improve the availability, access, uptake, and adherence to the best exercise recommendations in the routine management of people with PAD and IC.

Comparing 6-minute walk versus treadmill walking distance as outcomes in randomized trials of peripheral artery disease

BACKGROUND

Randomized trials of people with peripheral artery disease (PAD) and intermittent claudication have traditionally used maximal treadmill walking distance as the primary outcome, but the 6-minute walk test is increasingly used as a primary outcome in randomized trials of PAD. This study compared relative changes in maximal treadmill walking distance versus 6-minute walk distance in response to a therapeutic intervention or control in randomized trials of participants with PAD.

METHODS

Data from four randomized trials of therapeutic interventions in participants with PAD that measured both 6-minute walk and treadmill walking performance at baseline and the 6-month follow-up were combined. Two trials studied supervised treadmill exercise, one studied home-based walking exercise, and one studied resveratrol.

RESULTS

Of 467 participants (mean age, 69.8; standard deviation, 9.7), the mean ankle-brachial index was 0.66 (standard deviation, 0.17). At the 6-month follow-up, participants with PAD randomized to control or placebo significantly declined in 6-minute walk distance (-10.2 m; 95% confidence interval, -18.2 to -2.2; P = .013), but improved maximal treadmill walking distance (+25.7 m; 95% CI, +6.0 to +45.3 m; P = .010; difference between change in 6-minute walk versus maximal treadmill walking distance: -37.3 m; 95% CI, -56.4 to -18.2; P < .001). Home-based exercise improved the 6-minute walk distance by 43.2 m (95% CI, +28.4 to +57.9), and supervised treadmill exercise improved the 6-minute walk distance by 25.0 m (95% CI, +14.7 to +35.2; mean difference, +18.2 m favoring home-based exercise [95% CI, +0.2 to +36.2 m; P = .048]). Among all participants, the presence (vs absence) of treadmill exercise training was associated with a 141.3-m greater improvement in maximal treadmill walking distance compared to 6-minute walk distance (95% CI, 88.2-194.4; P < .001), suggesting a benefit from treadmill training on the treadmill outcome.

CONCLUSIONS

Maximal treadmill walking distance and the 6-minute walk distance are not interchangeable outcomes in participants with PAD. Participants with PAD randomized to control groups improved treadmill walking distance but simultaneously meaningfully declined in 6-minute walk distance. Supervised treadmill exercise training amplified improvement in treadmill walking distance because of a training to the outcome measure phenomenon.

How To Assess a Claudication and When To Intervene

PURPOSE OF THE REVIEW

Peripheral artery disease (PAD) affects close to 200 million people worldwide. Claudication is the most common presenting symptom for patients with PAD. This review summarizes the current diagnostic and treatment options for patients with claudication. Comprehensive history and physical examination in order to differentiate between claudication secondary to vascular disease vs. neurogenic causes is paramount for initial diagnosis. Ankle-brachial index is the most commonly used test for screening and diagnostic purposes. Treatment consists of four different approaches, which are best utilized in combination: non-pharmacological treatment for claudication improvement, pharmacological treatment for claudication improvement, pharmacological treatment for secondary risk reduction, and interventional treatment for claudication improvement.

RECENT FINDINGS

Cilostazol is the only Food and Drug Administration (FDA)-approved agent for symptomatic treatment of claudication. Supervised exercise programs provide the maximum benefit for claudication improvement, but home-based exercise programs are an alternative. High-intensity statins and an antiplatelet agent should be prescribed to all patients with PAD. Angiotensin-converting-enzyme inhibitors can provide additional risk reduction, especially in patients with diabetes or hypertension. Rivaroxaban of low dosage (2.5 mg twice daily) in combination with aspirin further decreases cardiovascular risk, but this reduction comes at the cost of higher bleeding risk. Peripheral artery disease (PAD) is a form of atherosclerotic disease that affects hundreds of millions of people worldwide-one of its most common manifestations is intermittent claudication (IC), which results from insufficient blood flow to meet the metabolic demands of an affected extremity. This paper reviews the current literature regarding the workup, diagnosis, diagnostic modalities, treatment options, and management of intermittent claudication.

Association of Computed Tomographic Leg Muscle Characteristics With Lower Limb and Cardiovascular Events in Patients With Peripheral Artery Disease

Background Poor lower extremity physical performance is an independent predictor of unfavorable outcome in patients with peripheral artery disease ( PAD ); however, few studies have assessed muscle characteristics on imaging directly. Method and Results A novel 3-dimensional semi-automated protocol was developed to estimate leg muscle volume and density (mean attenuation) from computed tomography images. Patients with PAD who underwent a lower extremity computed tomography scan at a tertiary vascular surgery center were included, and were followed up using hospital records and linked data as part of a retrospective cohort study. The primary outcomes were lower limb events (major amputation or peripheral revascularization) and cardiovascular events (myocardial infarction, stroke, or cardiovascular death). Two hundred and twenty-three patients with PAD were included (median age 69.0 years; 73% men) and followed for a median of 4.9 [2.6-7.0] years. During this time there were 99 index lower limb events and 97 cardiovascular events. Low leg muscle density was associated with increased risk of lower limb (rate ratio 1.41 [1.11-1.80] per SD reduction) and cardiovascular events (rate ratio 1.60 [1.29-1.99] per SD reduction). Low muscle density remained an independent predictor of cardiovascular (but not lower limb) events, after adjusting for age, sex, traditional cardiovascular risk factors, and angiographic PAD severity (rate ratio 1.39 [1.09-1.77] per lower SD ). In contrast, leg muscle volume was not associated with outcomes after adjusting for risk factors and PAD severity. Conclusions Low leg muscle density, but not volume, is a strong, independent predictor of major cardiovascular events among people with PAD . Further research is needed to understand the mechanisms underlying these associations.

Efficacy of whole-body suspension training on enhancing functional movement abilities following a supervised or home-based training program

BACKGROUND

The purpose of this study was to determine the effects of suspension training on functional movement and body composition, and to compare the effectiveness of home-based training to supervised training.

METHODS

Seventeen healthy subjects (8 males, 9 females, age=21.8±3.4 y) with no recent history of resistance training were randomly assigned to a home-based or supervised training group. Subjects performed an 8-week suspension training program consisting of 10 exercises targeting major muscle groups, twice per week for the duration of the study. Pre- and post-intervention testing included body composition using air displacement plethysmography, and a functional movement screen (FMS) to measure functional movement abilities.

RESULTS

The 8-week training program significantly improved total FMS scores across the whole sample of subjects (Pre=16.4; Post=17.5; P=0.004), with no differences in improvements between groups. When compared separately, only the supervised group significantly improved FMS scores. There was also a significant increase in lean mass across the total sample of subjects (Pre=52.4 kg; Post=53.3 kg; P=0.03) with no differences between groups. But when compared independently, neither group exhibited a significant increase in lean mass.

CONCLUSIONS

When completed as a whole-body exercise program over an 8-week period, suspension training can improve functional ability and increase lean mass in both a supervised and a home-based setting.

Peripheral arterial disease: Scoping review of patient-centred outcomes

Peripheral arterial disease (PAD) impairs patients' quality of life (QOL), walking and ulcer healing, increasing patient pain, costs, and risks of amputation or mortality. A literature appraisal described PAD treatment capacity to improve validated patient-centred outcomes in controlled clinical studies. The PUBMED database was searched from 1 January 1970 to 21 June 2018, for original and derivative controlled clinical trial references addressing MeSH terms for 'ischemia' AND 'leg ulcer'. Non-ischemic ulcer treatment references were excluded. Frequencies of improved (P < .05) outcomes were reported. Eighty-eight studies on 4153 patients were summarized. Walking, pain or QOL improved mainly for interventions administered before PAD became severe. Amputation incidence, pain and ulcer healing were more frequently reported in those with severe PAD. Independent of PAD severity, patients experienced more likely improved walking, QOL, or pain reduction in response to structured walking interventions or those increasing calf muscle activity. Those with more severe PAD were more likely to report amputation reduction, mainly in response to invasive interventions. Those with PAD experienced more consistently improved patient-centred outcomes if they received multidisciplinary PAD management with supervised walking or calf muscle activity, with more likely amputation risk reduced for those with more severe PAD.

Peripheral Arterial Disease: Supervised Exercise Therapy Through Cardiac Rehabilitation

Peripheral arterial disease (PAD) is frequently underdiagnosed and undertreated. This review identifies specific subgroups within older adults more likely to develop PAD, and describes methods to diagnose PAD and provide evidence in support of systematic referral to cardiac rehabilitation programs to enhance successful comprehensive management. Clear evidence and guidelines support the routine use of supervised exercise therapy to improve function, reduce risk of cardiovascular morbidity and mortality, and enhance the success of endovascular interventions.

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

Patients with lower-extremity peripheral artery disease (PAD) have greater functional impairment, faster functional decline, increased rates of mobility loss, and poorer quality of life than people without PAD. Supervised exercise therapy (SET) improves walking ability, overall functional status, and health-related quality of life in patients with symptomatic PAD. In 2017, the Centers for Medicare & Medicaid Services released a National Coverage Determination (CAG-00449N) for SET programs for patients with symptomatic PAD. This advisory provides a practical guide for delivering SET programs to patients with PAD according to Centers for Medicare & Medicaid Services criteria. It summarizes the Centers for Medicare & Medicaid Services process and requirements for referral and coverage of SET and provides guidance on how to implement SET for patients with PAD, including the SET protocol, options for outcome measurement, and transition to home-based exercise. This advisory is based on the guidelines established by the Centers for Medicare & Medicaid Services for Medicare beneficiaries in the United States and is intended to assist clinicians and administrators who are implementing SET programs for patients with PAD.

Motivating Structured walking Activity in people with Intermittent Claudication (MOSAIC): protocol for a randomised controlled trial of a physiotherapist-led, behavioural change intervention versus usual care in adults with intermittent claudication

INTRODUCTION

Walking exercise is a recommended but underused treatment for intermittent claudication caused by peripheral arterial disease (PAD). Addressing the factors that influence walking exercise may increase patient uptake of and adherence to recommended walking. The primary aim of this randomised controlled trial (RCT) is to evaluate the efficacy of a physiotherapist-led behavioural change intervention on walking ability in adults with intermittent claudication (MOtivating Structured walking Activity in people with Intermittent Claudication (MOSAIC)) in comparison with usual care.

METHODS AND ANALYSIS

The MOSAIC trial is a two-arm, parallel-group, single-blind RCT. 192 adults will be recruited from six National Health Service Hospital Trusts. Inclusion criteria are: aged ≥50 years, PAD (Ankle Brachial Pressure Index ≤0.90, radiographic evidence or clinician report) and intermittent claudication (San Diego Claudication Questionnaire), being able and willing to participate and provide informed consent. The primary outcome is walking ability (6 min walking distance) at 3 months. Outcomes will be obtained at baseline, 3 and 6 months by an assessor blind to group allocation. Participants will be individually randomised (n=96/group, stratified by centre) to receive either MOSAIC or usual care by an independent randomisation service. Estimates of treatment effects will use an intention-to-treat framework implemented using multiple regression adjusted for baseline values and centre.

ETHICS AND DISSEMINATION

This trial has full ethical approval (London-Bloomsbury Research Ethics Committee (17/LO/0568)). It will be disseminated via patient forums, peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ISRCTN14501418.

Supervised walking exercise therapy improves gait biomechanics in patients with peripheral artery disease

OBJECTIVE

In patients with peripheral artery disease (PAD), supervised exercise therapy is a first line of treatment because it increases maximum walking distances comparable with surgical revascularization therapy. Little is known regarding gait biomechanics after supervised exercise therapy. This study characterized the effects of supervised exercise therapy on gait biomechanics and walking distances in claudicating patients with PAD.

METHODS

Forty-seven claudicating patients with PAD underwent gait analysis before and immediately after 6 months of supervised exercise therapy. Exercise sessions consisted of a 5-minute warmup of mild walking and stretching of upper and lower leg muscles, 50 minutes of intermittent treadmill walking, and 5 minutes of cooldown (similar to warmup) three times per week. Measurements included self-perceived ambulatory limitations measured by questionnaire, the ankle-brachial index (ABI), walking distance measures, maximal plantar flexor strength measured by isometric dynamometry, and overground gait biomechanics trials performed before and after the onset of claudication pain. Paired t-tests were used to test for differences in quality of life, walking distances, ABI, and maximal strength. A two-factor repeated measures analysis of variance determined differences for intervention and condition for gait biomechanics dependent variables.

RESULTS

After supervised exercise therapy, quality of life, walking distances, and maximal plantar flexor strength improved, although the ABI did not significantly change. Several gait biomechanics parameters improved after the intervention, including torque and power generation at the ankle and hip. Similar to previous studies, the onset of claudication pain led to a worsening gait or a gait that was less like healthy individuals with a pain-free gait.

CONCLUSIONS

Six months of supervised exercise therapy produced increases in walking distances and quality of life that are consistent with concurrent improvements in muscle strength and gait biomechanics. These improvements occurred even though the ABI did not improve. Future work should examine the benefits of supervised exercise therapy used in combination with other available treatments for PAD.

Feasibility and Clinical Relevance of a Mobile Intervention Using TrackPAD to Support Supervised Exercise Therapy in Patients With Peripheral Arterial Disease: Study Protocol for a Randomized Controlled Pilot Trial

Background

Peripheral arterial disease (PAD) is a common and severe disease with a highly increased cardiovascular morbidity and mortality. Through the circulatory disorder and the linked undersupply of oxygen carriers in the lower limbs, the ongoing decrease of the pain-free walking distance occurs with a significant reduction in patients’ quality of life. Studies including activity monitoring for patients with PAD are rare and digital support to increase activity via mobile health technologies is mainly targeted at patients with cardiovascular disease in general. The special requirement of patients with PAD is the need to reach a certain pain level to improve the pain-free walking distance. Unfortunately, both poor adherence and availability of institutional resources are major problems in patient-centered care.

Objective

The objective of this trackPAD pilot study is to evaluate the feasibility of a mobile phone–based self tracking app to promote physical activity and supervised exercise therapy (SET) in particular. We also aim for a subsequent patient centered adjustment of the app prototype based on the results of the app evaluation and process evaluation.

Methods

This study was designed as a closed user group trial, with assessors blinded, and parallel group study with face-to-face components for assessment with a follow-up of 3 months. Patients with symptomatic PAD (Fontaine stage IIa or IIb) and possession of a mobile phone were eligible. Eligible participants were randomly assigned into study and control group, stratified by their distance covered in the 6-min walk test, using the software TENALEA. Participants randomized to the study group received usual care and the mobile intervention (trackPAD) for the follow-up period of 3 months, whereas participants randomized to the control group received only usual care. TrackPAD records the frequency and duration of training sessions and pain level using manual user input. Clinical outcome data were collected at the baseline and after 3 months via validated tools (6-min walk test, ankle-brachial index, and duplex ultrasound at the lower arteries) and self-reported quality of life. Usability and quality of the app was determined using the user version of the Mobile Application Rating Scale.

Results

The study enrolled 45 participants with symptomatic PAD (44% male). Of these participants, 21 (47%) were randomized to the study group and 24 (53%) were randomized to the control group. The distance walked in the 6-min walk test was comparable in both groups at baseline (study group: mean 368.1m [SD 77.6] vs control group: mean 394.6m [SD 100.6]).

Conclusions

This is the first trial to test a mobile intervention called trackPAD that was designed especially for patients with PAD. Its results will provide important insights in terms of feasibility, effectiveness, and patient preferences of an app-based mobile intervention supporting SET for the conservative treatment of PAD.

International Registered Report Identifier (IRRID)

DERR1-10.2196/13651

The Effect of Supervised Exercise, Home Based Exercise and Endovascular Revascularisation on Physical Activity in Patients With Intermittent Claudication: A Network Meta-analysis

BACKGROUND

It is unclear whether supervised exercise therapy (SET), home based exercise therapy (HBET), and endovascular revascularisation (ER) for intermittent claudication (IC) have a meaningful impact on physical activity, despite extensive research on their effect on walking performance.

METHODS

Multiple databases were searched systematically up to May 2018 for randomised controlled trials with objective measurements of physical activity in patients with IC. A Bayesian network meta-analysis was performed comparing the change in physical activity between baseline and follow up between treatments (SET, HBET, ER) and control (usual care). The standardised mean difference (SMD) with 95% credible interval (CI) was calculated as a summary statistic and converted into steps per day to aid interpretation.

RESULTS

Eight trials involving 656 patients with IC investigating the short-term effect of treatment on daily physical activity were included. Both SET (SMD 0.41, 95% CI 0.10-0.72: this corresponds to a difference of + 803 steps/day on a pedometer) and HBET (SMD 0.50, 95% CI 0.18-0.88: + 980 steps/day) displayed a benefit over control, based on evidence of moderate and low quality, respectively. The benefit of ER compared with control was SMD 0.36 (95% CI -0.22 to 0.99: + 705 steps/day), but only one trial supplied direct evidence, resulting in a low rating of the quality of evidence. Comparisons between treatments yielded no statistically significant differences. The results were robust to several sensitivity analyses.

CONCLUSION

SET improves daily physical activity levels in patients with IC over control. HBET may have a similar benefit, while invasive treatment failed to lead to a statistically significant improvement of physical activity compared with control. However, the underlying quality of evidence for comparisons with ER and HBET is low, impeding definite conclusions.

Effect of Resveratrol on Walking Performance in Older People With Peripheral Artery Disease: The RESTORE Randomized Clinical Trial

Importance

Research shows that resveratrol, a sirtuin activator in red wine, improves exercise endurance and skeletal-muscle oxidative metabolism in animals and may enhance vascular function in humans. Resveratrol supplement sales exceed $30 million annually in the United States, but few data are available regarding its efficacy in humans.

Objective

To determine whether resveratrol, 125 mg/d or 500 mg/d, improves the 6-minute walk performance in patients with peripheral artery disease (PAD).

Design, Setting, and Participants

This parallel-design, double-blind, randomized clinical trial, called Resveratrol to Improve Outcomes in Older People With PAD (RESTORE), was conducted at Northwestern University. Sixty-six participants 65 years or older with PAD were randomized to receive a daily capsule of resveratrol, 125 mg or 500 mg, or placebo for 6 months. Participants were randomized using a randomly permuted block method stratified by baseline 6-minute walk test performance. This trial was conducted between January 1, 2015, and August 5, 2016, and data analyses were performed according to the intention-to-treat concept.

Interventions

Administration of resveratrol, 125 or 500 mg/d, or placebo once daily.

Main Outcomes and Measures

The primary outcome measure was the change in 6-minute walk distance at the 6-month follow-up. One of the secondary outcomes was change in maximal treadmill walking time. Because of the preliminary nature of the trial, the a priori power calculation used a 1-sided test with a significance level of P < .10.

Results

The 66 participants were predominantly men (45 [68%]), had a mean (SD) age of 74.4 (6.6) years, and had a mean (SD) ankle brachial index of 0.67 (0.18). Sixty-four (97%) completed follow-up. Six-month mean (SE) changes in 6-minute walk distance were 4.6 (8.1) m for the 125-mg resveratrol group, -12.8 (7.5) m for the 500-mg resveratrol group, and -12.3 (7.9) m for the placebo group (P = .07 for the 125-mg resveratrol group vs placebo; P = .96 for the 500-mg resveratrol group vs placebo). Six-month mean (SE) changes in maximal treadmill walking time were 0.5 (2.3) minutes for the 125-mg resveratrol group, -0.6 (2.1) minutes for the 500-mg resveratrol group, and 0.4 (2.1) minutes for the placebo group (P = .18 for the 125-mg resveratrol group vs placebo; P = .12 for the 500-mg resveratrol group vs placebo).

Conclusions and Relevance

The RESTORE trial found no consistent evidence that resveratrol improves walking performance in patients 65 years or older with PAD.

Trial Registration

clinicaltrials.gov Identifier: NCT02246660.

Efficacy of ankle-foot orthoses on walking ability in peripheral artery disease

Calf claudication is a significant cause of walking limitation for patients with peripheral artery disease (PAD). Ankle-foot orthoses (AFO) are leg devices that can reduce the physical demands on the calf muscles during ambulation. The purpose of this study was to determine the efficacy of AFO on walking ability in patients with PAD. This was an open-label, interventional trial including 15 patients with calf claudication who were fit with AFO. Patients completed graded treadmill testing, followed by 12 weeks of unstructured community-based walking using the AFO ad libitum. Comparison of peak walking time (PWT) at baseline versus 12 weeks was the primary outcome. A secondary outcome was claudication onset time (COT) assessed during graded treadmill tests. Change in walking ability of AFO group patients was also compared to outcomes from a historical PAD control group (n = 10) who received upfront advice to walk at home. Patients in the AFO group significantly improved their walking ability from baseline to 12 weeks (mean ± SD) (PWT: 7.8 ± 5.1 to 9.3 ± 5.4 min, p = 0.049; COT: 3.0 ± 2.3 to 4.8 ± 2.7 min, p = 0.01). Change in PWT for AFO group patients when tested without using the devices was not significantly greater compared to historical controls (+1.4 ± 2.4 vs +0.1 ± 2.6 min, p = 0.16) but it was for COT (+1.8 ± 2.5 vs -0.6 ± 2.2 min, p = 0.02). This study found that AFO used during community-based walking improved the primary outcome of PWT in patients with PAD. Further, using AFO delayed claudication onset, indicating patients may be able to increase their walking activity. Large-scale, randomized controlled trials are needed to further explore the use of AFO for PAD. ClinicalTrials.gov identifier: NCT02280200.

Changes in vascular and inflammatory biomarkers after exercise rehabilitation in patients with symptomatic peripheral artery disease

OBJECTIVE

Home-based exercise is an alternative exercise mode to a structured supervised program to improve symptoms in patients with peripheral artery disease (PAD), but little is known about whether the slow-paced and less intense home program also elicits changes in vascular and inflammatory biomarkers. In an exploratory analysis from a randomized controlled trial, we compared changes in vascular and inflammatory biomarkers in patients with symptomatic PAD (typical and atypical of claudication) after home-based exercise and supervised exercise programs and in an attention-control group.

METHODS

A total of 114 patients were randomized into one of the three groups (n = 38 per group). Two groups performed exercise interventions, consisting of home-based and supervised programs of intermittent walking to mild to moderate claudication pain for 12 weeks; a third group performed light resistance training as a nonwalking attention-control group. Before and after intervention, patients were characterized on treadmill performance and endothelial effects of circulating factors present in sera by a cell culture-based bioassay on primary human arterial endothelial cells, and they were further evaluated on circulating vascular and inflammatory biomarkers.

RESULTS

Treadmill peak walking time increased (P = .008) in the two exercise groups but not in the control group (P > .05). Cultured endothelial cell apoptosis decreased after home-based exercise (P < .001) and supervised exercise (P = .007), and the change in the exercise groups combined was different from that in the control group (P = .005). For circulating biomarkers, increases were found in hydroxyl radical antioxidant capacity (P = .003) and vascular endothelial growth factor A (P = .037), and decreases were observed in E-selectin (P = .007) and blood glucose concentration (P = .012) after home-based exercise only. The changes in hydroxyl radical antioxidant capacity (P = .005), vascular endothelial growth factor A (P = .008), and E-selectin (P = .034) in the exercise groups combined were different from those in the control group.

CONCLUSIONS

This exploratory analysis found that both home-based and supervised exercise programs are efficacious to decrease cultured endothelial cell apoptosis in patients with symptomatic PAD. Furthermore, a monitored home-based exercise program elicits additional vascular benefits by improving circulating markers of endogenous antioxidant capacity, angiogenesis, endothelium-derived inflammation, and blood glucose concentration in patients with symptomatic PAD. The novel clinical significance is that important trends were found in this exploratory analysis that a contemporary home-based exercise program and a traditional supervised exercise program may favorably improve vascular and inflammatory biomarkers in addition to the well-described ambulatory improvements in symptomatic patients with PAD.

Experience Implementing Supervised Exercise Therapy for Peripheral Artery Disease

Background

Supervised exercise therapy (SET) is a cornerstone of treatment for improving walking distance for individuals with symptomatic peripheral artery disease and claudication. High quality randomized controlled trials have documented the efficacy of SET as a claudication treatment and led to the recent Centers for Medicare and Medicaid decision to cover supervised exercise therapy (SET). However, to date, the translation of highly controlled, laboratory based SET programs in real world cardiopulmonary rehabilitation settings has been unexplored.

Methods

In this article, we describe our experience integrating SET into existing cardiopulmonary rehabilitation programs, focusing on patient evaluation, exercise prescription, outcome assessments, strategies to maximize program adherence, and transitioning to home and community-based exercise training.

Results

Our team has over 3 years experience successfully implementing SET in cardiac rehabilitation settings. The experiences communicated within can serve as a model for rehabilitation therapists to follow as they begin to incorporate SET in their rehabilitation programs.

Conclusions

CMS reimbursement has the potential to change clinical practice and utilization of SET for patients with symptomatic peripheral artery disease. The experience we have gained through implementation of SET programs across the M Health and Fairview Health Systems and in other Minnesota communities, including specific elements in our programs and the lessons learned from our clinical experience, can inform and help to guide development of new programs.

Brief Abstract

The recent Centers for Medicare and Medicaid decision to cover supervised exercise therapy (SET) for beneficiaries with peripheral artery disease (PAD) has the potential to transform practice. In this article, we describe our experience integrating SET into existing cardiopulmonary rehabilitation programs, which could serve as a model for new programs.

Meta-analysis of clinical trials examining the benefit of structured home exercise in patients with peripheral artery disease

Background

Supervised exercise is recommended for the management of peripheral artery disease (PAD); however, the uptake is limited. Structured home exercise programmes may be more feasible, but their effectiveness is unclear. This systematic review and meta-analysis examined the benefit of structured home exercise programmes for treating PAD in comparison to controls not receiving an exercise programme.

Methods

A literature search was conducted to identify RCTs comparing structured home exercise with controls not receiving an exercise programme among patients with PAD. To be included, studies had to report outcomes from treadmill or corridor walking tests, or objective assessment of physical activity. Inverse variance-weighted meta-analysis was performed to compare changes in maximum walking distance and intermittent claudication onset distance in treadmill tests, walking distance during a 6-min walking test, and physical activity measured using a pedometer or accelerometer. Summarized results are presented in terms of standard deviation differences.

Results

Eleven randomized trials involving 807 patients were included. Follow-up ranged from 2 to 24 months; only one trial included follow-up beyond 12 months. Meta-analyses showed that structured home exercise programmes led to significant improvements in maximum walking distance (mean difference (MD) 0·32, 95 per cent c.i. 0·15 to 0·50; P &lt; 0·001), intermittent claudication onset distance (MD 0·45, 0·27 to 0·62; P &lt; 0·001), walking distance in a 6-min walking test (MD 0·28, 0·09 to 0·47; P = 0·004) and physical activity (MD 0·27, 0·11 to 0·43; P = 0·001).

Conclusion

This meta-analysis suggests that structured home exercise programmes are effective at improving walking performance and physical activity in the short term for patients with PAD.

Efficacy of Community-Based Exercise Therapy Among African American Patients With Peripheral Artery Disease: A Randomized Clinical Trial

IMPORTANCE

African American individuals are 2 times more likely than non-Hispanic white individuals to have peripheral artery disease (PAD). Structured community-based exercise therapy improves walking distance among patients with PAD, but these patients require motivation to adhere to therapy.

OBJECTIVE

To assess whether motivational interviewing (MI) is more efficacious than Patient-Centered Assessment and Counseling for Exercise (PACE) or control to improve walking distance in African American patients with PAD.

DESIGN, SETTING, AND PARTICIPANTS

In this 3-group randomized clinical trial, 174 African American patients with PAD were studied from May 1, 2012, to November 30, 2016, at health care centers, churches, and health fairs in Wichita, Kansas; Kansas City, Kansas, and Kansas City, Missouri.

INTERVENTIONS

Patients were randomized in a 1:1:1 fashion to 1 of 3 groups (57 to MI, 57 to PACE, and 60 to control). The 2 counseling interventions were delivered biweekly for 3 months and monthly for 3 months followed by a 6-month maintenance phase with limited contact. Control participants received a mailing at 3 and 9 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was 6-month change in 6-minute walking performance. Secondary outcomes included 12-month change in walking performance and 6- and 12-month changes in quality of life.

RESULTS

A total of 174 African American patients (mean [SD] age, 64.2 [11.2] years; 128 [74.0%] female) were studied. At 6 months, mean (SE) change in walking distance by group was as follows: MI, -3.42 (4.55) m; PACE, 2.74 (6.00) m; and control, -0.18 (4.40) m. At 12 months, mean (SE) change in walking distance by group was as follows: MI, -7.75 (5.50) m; PACE, 13.75 (6.13) m; and control, -1.08 (5.73) m. Comparing each of the intervention arms (MI and PACE) with the control arm, no statistically significant increases in walking distance at 6 months (MI: change, -2.10 m; 95% CI, -16.54 to 12.35 m; PACE: change, 2.31 m; 95% CI, -11.36 to 15.97 m) or 12 months (MI: change, -5.56 m; 95% CI, -21.18 to 10.06 m; PACE: change, 14.24 m; 95% CI, -1.85 to 30.34 m) were found. Compared with MI, PACE resulted in a statistically significant increase in walking distance at 12 months of 19.80 m (95% CI, 3.33-36.28 m).

CONCLUSIONS AND RELEVANCE

In a cohort of African American patients with PAD, MI was not efficacious in improving walking distance at 6 or 12 months. The results of this study do not support the use of MI to improve walking performance in African American patients with PAD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01321086.

EFFECTS OF WALKING ON THE MOOD OF PHYSICALLY ACTIVE OLDER PEOPLE

ABSTRACT Introduction: Due to the relationship between exercise and mood (MO), physical activity is being widely used as a nonpharmacological strategy in the treatment of depression. However, most studies have used sample groups of subjects who, besides suffering from ill health, are also older and sedentary, thus presenting wider “windows of adaptations” when compared to apparently healthy or physically active individuals. Thus, the effects of exercise on MO in physically active elderly individuals are yet to be clarified. Objective: To verify the acute effects of 30 minutes of walking of mild to moderate intensity on the MO of physically active elderly subjects. Methods: A total of 43 volunteers (86% women and 14% men), who participated regularly in an activity program offered by a health care institution in Alagoas, were selected in a non-probabilistic manner. MO was evaluated using the Profile of Mood States (POMS) questionnaire before and after 30 minutes of walking. The comparison between means was verified with Student's t-test. Results: Relative differences were observed in all dimensions of MO, ranging from 16.4% (Vigor) to 56.3% (Rage). However, statistically significant differences were only found in the Vigor (p = 0.00) and Confusion (p = 0.026) dimensions. Conclusion: It is concluded that a 30-minute walk, performed at mild to moderate intensity, as recommended by the main medical guidelines for obtaining general health benefits, may be an effective way of promoting MO improvements in physically active elderly people. The study confirms the fact that walking may potentially be an interesting nonpharmacological strategy for the treatment of depression. Level of Evidence II; Therapeutic studies - Investigating treatment results.

Racial Differences in the Effect of Granulocyte Macrophage Colony-Stimulating Factor on Improved Walking Distance in Peripheral Artery Disease: The PROPEL Randomized Clinical Trial

Background The effects of race on response to medical therapy in people with peripheral artery disease ( PAD ) are unknown. Methods and Results In the PROPEL (Progenitor Cell Release Plus Exercise to Improve Functional Performance in PAD) Trial, PAD participants were randomized to 1 of 4 groups for 6 months: supervised treadmill exercise+granulocyte-macrophage colony-stimulating factor ( GM - CSF ) (Group 1), exercise+placebo (Group 2), attention control+ GM - CSF (Group 3), or attention control+placebo (Group 4). Change in 6-minute walk distance was measured at 12- and 26-week follow-up. In these exploratory analyses, groups receiving GM - CSF (Groups 1 and 3), placebo (Groups 2 and 4), exercise (Groups 1 and 2), and attention control (Groups 2 and 4) were combined, maximizing statistical power for studying the effects of race on response to interventions. Of 210 PAD participants, 141 (67%) were black and 64 (30%) were white. Among whites, GM - CSF improved 6-minute walk distance by +22.0 m (95% CI : -4.5, +48.5, P=0.103) at 12 weeks and +44.4 m (95% CI : +6.9, +82.0, P=0.020) at 26 weeks, compared with placebo. Among black participants, there was no effect of GM - CSF on 6-minute walk distance at 12-week ( P=0.26) or 26-week (-5.0 m [-27.5, +17.5, P=0.66]) follow-up, compared with placebo. There was an interaction of race on the effect of GM - CSF on 6-minute walk change at 26-week follow-up ( P=0.018). Exercise improved 6-minute walk distance in black ( P=0.006) and white ( P=0.034) participants without interaction. Conclusions GM - CSF improved 6-minute walk distance in whites with PAD but had no effect in black participants. Further study is needed to confirm racial differences in GM - CSF efficacy in PAD . Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01408901.

Are There Limitations to Exercise Benefits in Peripheral Arterial Disease?

Substantial evidence exists indicating that inactivity contributes to the progression of chronic disease, and conversely, that regular physical activity can both prevent the onset of disease as well as delay the progression of existing disease. To that end "exercise as medicine" has been advocated in the broad context as general medical care, but also in the specific context as a therapeutic, to be considered in much the same way as other drugs. As there are non-responders to many medications, there also are non-responders to exercise; individual who participate but do not demonstrate appreciable improvement/benefit. In some settings, the stress induced by exercise may aggravate an underlying condition, rather than attenuate chronic disease. As personalized medicine evolves with ready access to genetic information, so too will the incorporation of exercise in the context of those individual genetics. The focus of this brief review is to distinguish between the inherent capacity to perform, as compared to adaptive response to active exercise training in relation to cardiovascular health and peripheral arterial disease.

Brachial artery intima-media thickness and grayscale texture changes in patients with peripheral artery disease receiving supervised exercise training in the PROPEL randomized clinical trial

We performed an exploratory analysis to evaluate the effects of a treadmill exercise program on brachial artery (BA) intima-media thickness (IMT) and three BA grayscale ultrasound measures that may indicate subclinical arterial injury. Data were from a clinical trial in individuals with peripheral artery disease who were randomly assigned to treadmill exercise training or attention control. B-mode ultrasonography was performed at baseline and after 26 weeks. BA IMT, grayscale median (GSM), entropy, and gray-level difference statistic-contrast (GLDS-CON) were measured by a single reader. The 184 participants were (mean (SD)) 66.7 (8.2) years old and had an ankle-brachial index of 0.70 (0.18). Exercise training was associated with a 0.01 (0.06) mm ( p = 0.025) reduction in BA IMT compared to 0.00 (0.05) mm ( p = 0.807) in the control group (between-group p = 0.061). BA GSM, entropy, and GLDS-CON did not change significantly with exercise. Improvements in the 6-minute walk distance correlated with increases in resting BA blood flow ( r = 0.23, p = 0.032), flow-mediated dilation ( r = 0.24, p = 0.022), diameter ( r = 0.29, p = 0.005), entropy ( r = 0.21, p = 0.047), and GLDS-CON ( r = 0.22, p = 0.041). In a post hoc analysis, BA IMT improved significantly with treadmill exercise training but did not change with attention control; however, the between-group difference did not reach statistical significance. With exercise, improvements in the 6-minute walk distance were associated with improved endothelial function, increased resting blood flow, and BA dilation, as well as higher grayscale entropy and GLDS-CON, indicating that lower extremity exercise is associated with salutary changes in upper-extremity arterial wall structure and function. ClinicalTrials.gov Identifier: NCT01408901.

Behavior-Change Intervention Targeting Physical Function, Walking, and Disability After Dysvascular Amputation: A Randomized Controlled Pilot Trial

OBJECTIVE

To determine preliminary efficacy of a home-based behavior-change intervention designed to promote exercise, walking activity, and disease self-management.

DESIGN

A single-blind, randomized controlled pilot trial.

SETTING

One Veterans Administration and 2 regional medical centers.

PARTICIPANTS

A total of 38 participants randomized to behavior-change intervention (n=19) or attention control (CTL; n=19) group.

INTERVENTIONS

Weekly 30-minute telephone sessions for 12 weeks with intervention group sessions focused on health behavior change and CTL group sessions focused on health status monitoring.

MAIN OUTCOME MEASURES

Physical function, walking activity (steps/d averaged over 10d), and disability were measured at baseline, 12 weeks (intervention end), and 24 weeks after baseline with the Timed Up and Go (TUG) test as the primary outcome measure.

RESULTS

The TUG test was not changed from baseline in either group and was not different between groups after 12 or 24 weeks. Several exploratory outcomes were assessed, including daily step count, which increased 1135 steps per day in the intervention group compared to 144 steps per day in the CTL group after 12 weeks (P=.03). Only the intervention group had within-group increase in steps per day from baseline to 12 (P<.001) and 24 (P=.03) weeks and spent significantly less time in sedentary activity (4.8% decrease) than the CTL group (0.2% decrease) at 24 weeks (P=.04). There were no other between-group differences in physical function or disability change over time.

CONCLUSION

The behavior-change intervention demonstrates promise for increasing walking activity for people with dysvascular transtibial amputation (TTA). The efficacy of implementing such intervention in the scope of conventional TTA rehabilitation should be further studied.

Gender Differences in Outcomes Following a Pain-Free, Home-Based Exercise Program for Claudication

Background: Peripheral artery disease (PAD) is a common cardiovascular pathology that affects mobility. In previous research, supervised exercise, a recommended treatment for claudication, was less effective in women. This study retrospectively investigated whether functional outcomes exhibit sex differences following a pain-free, home-based exercise program for PAD patients.

Materials and Methods: Patients with PAD and claudication enrolled to a structured home-based program from 2003 to 2016 were studied. The program was prescribed at the hospital and based on two daily 10-minute pain-free walking sessions at progressively increasing speed. Outcome measures, which were assessed at baseline and discharge, were pain threshold speed (PTS) and maximal (Smax) during a treadmill test and pain-free walking distance (PFWD) and total distance walked in 6 minutes (6MWD). The ankle-brachial index (ABI), program duration, and patient adherence were determined.

Results: A total of 1007 patients (women; n = 264; 26%) were enrolled. At baseline, compared to men, women exhibited similar ABI values but lower PTS and PFWD values (p < 0.001). At discharge, with similar adherence (score 3/4 ± 1 each) in both groups, superimposable improvements were observed for PTS (0.8 ± 0.8 km/h each), Smax (0.4 ± 0.5 km/h each), PFWD (women 95 ± 100; men 86 ± 104), 6MWD (women 32 ± 65; men 35 ± 58), and ABI (women 0.07 ± 0.12; men 0.06 ± 0.11) without between-group differences (confirmed after propensity analysis).

Conclusion: A personalized, structured pain-free exercise program for PAD patients performed inside the home for a few minutes a day was equally effective in both sexes. Programs favoring adherence and functional outcomes in women should be tested in prospective studies.

Systematic Review and Meta-analysis of Clinical Trials Examining the Benefit of Exercise Programmes Using Nordic Walking in Patients With Peripheral Artery Disease

OBJECTIVES

An exercise programme is part of the initial management of peripheral artery disease (PAD). Nordic walking uses poles and a core-focused walking technique to reduce the load on the legs, which may have advantages as an exercise programme for PAD. This systematic review examined the benefit of a Nordic walking programme for treating PAD compared with other programmes.

METHODS

A systematic approach was used to identify clinical trials comparing Nordic walking and control programmes in PAD patients. For inclusion, studies had to report maximum walking distance (MWD) measured with a treadmill test or corridor walking test both at entry and follow up. Study quality was appraised using the Cochrane collaboration tool for assessing risk of bias. An inverse variance weighted meta-analysis was performed to compare improvements in MWD.

RESULTS

Five independent trials involving 294 patients were identified. In three trials, supervised Nordic walking programmes were compared with supervised standard walking. One trial compared a home based Nordic walking programme with a similar standard walking programme. One trial compared a partly supervised Nordic walking programme with best medical management. Meta-analysis of all data suggested that MWD improvements were similar for patients treated by Nordic and standard walking programmes (standardised mean difference, SMD = 1.31, 95% CI -1.28 to 3.91; p = .322). Findings for completely supervised programmes were similar to the primary analysis (SMD = -0.79, 95% CI -2.81 to 1.24; p = .446) while those from partially supervised or home based programmes favoured Nordic walking (SMD = 4.46, 95% CI 3.39, 5.53; p < .001), mainly due to results from one home based trial.

CONCLUSIONS

This systematic review suggests no benefit of Nordic over standard walking as supervised exercise for PAD. Favourable results were reported for one home based Nordic walking programme. A larger trial is needed to assess whether this finding can be replicated or not.

Screening for Peripheral Artery Disease Using the Ankle-Brachial Index: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Peripheral artery disease (PAD) is associated with a high risk for cardiovascular events and poor ambulatory function, even in the absence of symptoms. Screening for PAD with the ankle-brachial index (ABI) may identify patients in need of treatment to improve health outcomes.

OBJECTIVE

To systematically review evidence for the US Preventive Services Task Force on PAD screening with the ABI, the diagnostic accuracy of the test, and the benefits and harms of treatment of screen-detected PAD.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant English-language studies published between January 2012 and May 2, 2017. Surveillance continued through February 7, 2018.

STUDY SELECTION

Studies of unselected or generally asymptomatic adults with no known cardiovascular disease.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Cardiovascular morbidity; PAD morbidity; mortality; health-related quality of life; diagnostic accuracy; and serious adverse events.

RESULTS

Five studies (N = 5864 participants) were included that examined the indirect evidence for the benefits and harms of screening and treatment of screen-detected PAD. No population-based screening trials evaluated the direct benefits or harms of PAD screening with the ABI alone. A single diagnostic accuracy study of the ABI compared with magnetic resonance angiography gold-standard imaging (n = 306) found low sensitivity (7%-34%) and high specificity (96%-100%) in a screening population. Two adequately powered trials (n = 4626) in asymptomatic populations with and without diabetes with a variably defined low ABI (≤0.95 or ≤0.99) showed no statistically significant effect of aspirin (100 mg daily) for composite CVD outcomes (adjusted hazard ratio [HR], 1.00 [95% CI, 0.81-1.23] and HR, 0.98 [95% CI, 0.76-1.26]). One trial (n = 3350) demonstrated no statistically significant increase in major bleeding events with the use of aspirin (adjusted HR, 1.71 [95% CI, 0.99- 2.97]) and no statistically significant increase in major gastrointestinal bleeding (relative risk, 1.13 [95% CI, 0.44-2.91]). Two exercise trials (n = 932) in screen-relevant populations reported no differences in quality of life, Walking Impairment Questionnaire walking distance, or symptoms at 12 and 52 weeks; no harms were reported.

CONCLUSIONS AND RELEVANCE

There was no direct evidence and limited indirect evidence on the benefits of PAD screening with the ABI in unselected or asymptomatic populations. Available studies suggest low sensitivity and lack of beneficial effect on health outcomes, but these studies have important limitations.

Medical Management of Functional Impairment in Peripheral Artery Disease: A Review

Lower extremity peripheral artery disease (PAD) now affects 200 million people worldwide and is a major cause of disability. Cilostazol is the only Federal Drug Administration approved medication for PAD-related ischemic symptoms that is recommended by clinical practice guidelines. Supervised treadmill exercise significantly improves treadmill walking performance in PAD. Recent evidence shows that home-based exercise interventions that include occasional medical center visits and incorporate behavioral change techniques also significantly improve walking endurance in PAD. Upper and lower extremity ergometry (cycling) also improve walking ability in PAD. A recent decision by the Center for Medicaid and Medicare Services to cover supervised exercise for people with symptomatic PAD will increase access to exercise for the large number of people disabled by PAD.

Effect of a Home-Based Exercise Intervention of Wearable Technology and Telephone Coaching on Walking Performance in Peripheral Artery Disease: The HONOR Randomized Clinical Trial

IMPORTANCE

Clinical practice guidelines support home-based exercise for patients with peripheral artery disease (PAD), but no randomized trials have tested whether an exercise intervention without periodic medical center visits improves walking performance.

OBJECTIVE

To determine whether a home-based exercise intervention consisting of a wearable activity monitor and telephone coaching improves walking ability over 9 months in patients with PAD.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial conducted at 3 US medical centers. Patients with PAD were randomized between June 18, 2015, and April 4, 2017, to home-based exercise vs usual care for 9 months. Final follow-up was on December 5, 2017.

INTERVENTIONS

The exercise intervention group (n = 99) received 4 weekly medical center visits during the first month followed by 8 months of a wearable activity monitor and telephone coaching. The usual care group (n = 101) received no onsite sessions, active exercise, or coaching intervention.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in 6-minute walk distance at 9-month follow-up (minimal clinically important difference [MCID], 20 m). Secondary outcomes included 9-month change in subcomponents of the Walking Impairment Questionnaire (WIQ) (0-100 score; 100, best), SF-36 physical functioning score, Patient-Reported Outcomes Measurement Information System (PROMIS) mobility questionnaire (higher = better; MCID, 2 points), PROMIS satisfaction with social roles questionnaire, PROMIS pain interference questionnaire (lower = better; MCID range, 3.5-4.5 points), and objectively measured physical activity.

RESULTS

Among 200 randomized participants (mean [SD] age, 70.2 [10.4] years; 105 [52.5%] women), 182 (91%) completed 9-month follow-up. The mean change from baseline to 9-month follow-up in the 6-minute walk distance was 5.5 m in the intervention group vs 14.4 m in the usual care group (difference, -8.9 m; 95% CI, -26.0 to 8.2 m; P = .31). The exercise intervention worsened the PROMIS pain interference score, mean change from baseline to 9 months was 0.7 in the intervention group vs -2.8 in the usual care group (difference, 3.5; 95% CI, 1.3 to 5.8; P = .002). There were no significant between-group differences in the WIQ score, the SF-36 physical functioning score, or the PROMIS mobility or satisfaction with social roles scores.

CONCLUSIONS AND RELEVANCE

Among patients with PAD, a home-based exercise intervention consisting of a wearable activity monitor and telephone coaching, compared with usual care, did not improve walking performance at 9-month follow-up. These results do not support home-based exercise interventions of wearable devices and telephone counseling without periodic onsite visits to improve walking performance in patients with PAD.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02462824.

Minimal clinically important differences in treadmill, 6-minute walk, and patient-based outcomes following supervised and home-based exercise in peripheral artery disease

We estimated minimal clinically important differences (MCIDs) for small, moderate, and large changes in measures obtained from a standardized treadmill test, a 6-minute walk test, and patient-based outcomes following supervised and home-based exercise programs in symptomatic patients with peripheral artery disease (PAD). 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). Using the distribution-based method to determine MCIDs, the MCIDs for small, moderate, and large changes in peak walking time (PWT) in the supervised exercise group were 38, 95, and 152 seconds, respectively, and the changes in claudication onset time (COT) were 35, 87, and 138 seconds. Similar MCID scores were noted for the home-based exercise group. An anchor-based method to determine MCIDs yielded similar patterns of small, moderate, and large change scores in PWT and COT, but values were 1-2 minutes longer than the distribution approach. In conclusion, 3 months of supervised and home-based exercise programs for symptomatic patients with PAD results in distribution-based MCID small, moderate, and large changes ranging from 0.5 and 2.5 minutes for PWT and COT. An anchor-based approach yields higher MCID values, ranging from a minimum of 73 seconds for COT to a maximum of 4 minutes for PWT. The clinical implication is that a goal for eliciting MCIDs in symptomatic PAD patients through a walking exercise intervention is to increase PWT and COT by up to 4 minutes, which corresponds to two work stages during the standardized progressive treadmill test.

Supervised exercise therapy versus home-based exercise therapy versus walking advice for intermittent claudication

BACKGROUND

Although supervised exercise therapy (SET) provides significant symptomatic benefit for patients with intermittent claudication (IC), it remains an underutilized tool. Widespread implementation of SET is restricted by lack of facilities and funding. Structured home-based exercise therapy (HBET) with an observation component (e.g., exercise logbooks, pedometers) and just walking advice (WA) are alternatives to SET. This is the second update of a review first published in 2006.

OBJECTIVES

The primary objective was to provide an accurate overview of studies evaluating effects of SET programs, HBET programs, and WA on maximal treadmill walking distance or time (MWD/T) for patients with IC. Secondary objectives were to evaluate effects of SET, HBET, and WA on pain-free treadmill walking distance or time (PFWD/T), quality of life, and self-reported functional impairment.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (December 16, 2016) and the Cochrane Central Register of Controlled Trials (2016, Issue 11). We searched the reference lists of relevant studies identified through searches for other potential trials. We applied no restriction on language of publication.

SELECTION CRITERIA

We included parallel-group randomized controlled trials comparing SET programs with HBET programs and WA in participants with IC. We excluded studies in which control groups did not receive exercise or walking advice (maintained normal physical activity). We also excluded studies comparing exercise with percutaneous transluminal angioplasty, bypass surgery, or drug therapy.

DATA COLLECTION AND ANALYSIS

Three review authors (DH, HF, and LG) independently selected trials, extracted data, and assessed trials for risk of bias. Two other review authors (MvdH and JT) confirmed the suitability and methodological quality of trials. For all continuous outcomes, we extracted the number of participants, mean outcome, and standard deviation for each treatment group through the follow-up period, if available. We extracted Medical Outcomes Study Short Form 36 outcomes to assess quality of life, and Walking Impairment Questionnaire outcomes to assess self-reported functional impairment. As investigators used different scales to present results of walking distance and time, we standardized reported data to effect sizes to enable calculation of an overall standardized mean difference (SMD). We obtained summary estimates for all outcome measures using a random-effects model. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

For this update, we included seven additional studies, making a total of 21 included studies, which involved a total of 1400 participants: 635 received SET, 320 received HBET, and 445 received WA. In general, SET and HBET programs consisted of three exercise sessions per week. Follow-up ranged from six weeks to two years. Most trials used a treadmill walking test to investigate effects of exercise therapy on walking capacity. However, two trials assessed only quality of life, functional impairment, and/or walking behavior (i.e., daily steps measured by pedometer). The overall methodological quality of included trials was moderate to good. However, some trials were small with respect to numbers of participants, ranging from 20 to 304.SET groups showed clear improvement in MWD/T compared with HBET and WA groups, with overall SMDs at three months of 0.37 (95% confidence interval [CI] 0.12 to 0.62; P = 0.004; moderate-quality evidence) and 0.80 (95% CI 0.53 to 1.07; P < 0.00001; high-quality evidence), respectively. This translates to differences in increased MWD of approximately 120 and 210 meters in favor of SET groups. Data show improvements for up to six and 12 months, respectively. The HBET group did not show improvement in MWD/T compared with the WA group (SMD 0.30, 95% CI -0.45 to 1.05; P = 0.43; moderate-quality evidence).Compared with HBET, SET was more beneficial for PFWD/T but had no effect on quality of life parameters nor on self-reported functional impairment. Compared with WA, SET was more beneficial for PFWD/T and self-reported functional impairment, as well as for some quality of life parameters (e.g., physical functioning, pain, and physical component summary after 12 months), and HBET had no effect.Data show no obvious effects on mortality rates. Thirteen of the 1400 participants died, but no deaths were related to exercise therapy. Overall, adherence to SET was approximately 80%, which was similar to that reported with HBET. Only limited adherence data were available for WA groups.

AUTHORS' CONCLUSIONS

Evidence of moderate and high quality shows that SET provides an important benefit for treadmill-measured walking distance (MWD and PFWD) compared with HBET and WA, respectively. Although its clinical relevance has not been definitively demonstrated, this benefit translates to increased MWD of 120 and 210 meters after three months in SET groups. These increased walking distances are likely to have a positive impact on the lives of patients with IC. Data provide no clear evidence of a difference between HBET and WA. Trials show no clear differences in quality of life parameters nor in self-reported functional impairment between SET and HBET. However, evidence is of low and very low quality, respectively. Investigators detected some improvements in quality of life favoring SET over WA, but analyses were limited by small numbers of studies and participants. Future studies should focus on disease-specific quality of life and other functional outcomes, such as walking behavior and physical activity, as well as on long-term follow-up.

Relationships Among Perceived Functional Capacity, Self-Efficacy, and Disability After Dysvascular Amputation

BACKGROUND

Prosthesis rehabilitation after dysvascular transtibial amputation (TTA) is focused on optimizing functional capacity with limited emphasis on promoting health self-efficacy. Self-efficacy interventions decrease disability for people living with chronic disease, but the influence of self-efficacy on disability is unknown for people with dysvascular TTA.

OBJECTIVES

To identify if self-efficacy mediates the relationship between self-reported functional capacity and disability after dysvascular TTA.

DESIGN

Cross-sectional, secondary data analysis.

SETTING

Outpatient rehabilitation facilities.

PARTICIPANTS

Thirty-eight men (63.6 ± 9.1 years old) with dysvascular TTA.

METHODS

Participants had been living with an amputation for less than 6 months and using walking as their primary form of locomotion using a prosthesis. The independent variable, functional capacity, was measured using the Prosthesis Evaluation Questionnaire-Mobility Scale (PEQ-MS). The proposed mediator, self-efficacy, was measured with the Self-Efficacy of Managing Chronic Disease questionnaire (SEMCD).

MAIN OUTCOME MEASURE

Disability was measured using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) questionnaire.

RESULTS

The relationship between self-reported functional capacity and disability is partially mediated by self-efficacy. Relationships between WHODAS 2.0 and PEQ-MS (r = -0.61), WHODAS 2.0 and SEMCD (r = -0.51), and PEQ-MS and SEMCD (r = 0.44) were significant (P < .01). Controlling for SEMCD (P = .04), the relationship between PEQ-MS and WHODAS 2.0 remained significant (P < .01). Statistically significant mediation was determined by a bootstrap method for the product of coefficients (95% confidence interval: -2.23, -7.39).

CONCLUSIONS

This study provides initial evidence that the relationship between self-reported functional capacity and disability is partially mediated by self-efficacy after dysvascular TTA. The longitudinal effect of self-efficacy should be further examined to identify causal pathways of disability after dysvascular amputation. Furthermore, additional factors contributing to the relationship between self-reported functional capacity and disability need to be identified.

LEVEL OF EVIDENCE

III.

Exercise Rehabilitation for Peripheral Artery Disease: A REVIEW

PURPOSE

To summarize evidence regarding exercise therapy for people with lower extremity peripheral artery disease (PAD).

METHODS

Literature was reviewed regarding optimal strategies for delivering exercise interventions for people with PAD. Randomized trial evidence and recent studies were emphasized.

RESULTS

Randomized clinical trial evidence consistently demonstrates that supervised treadmill exercise improves treadmill walking performance in people with PAD. A meta-analysis of 25 randomized trials (1054 participants) concluded that supervised treadmill exercise was associated with 180 m of improvement in maximal treadmill walking distance and 128 m of improvement in pain-free walking distance compared with a control group. Three randomized trials of 493 patients with PAD demonstrated that home-based walking exercise interventions that incorporate behavioral change techniques improve walking ability in patients with PAD. Furthermore, evidence suggests that home-based walking exercise improves the 6-min walk more than supervised treadmill exercise. Upper and lower extremity ergometry also significantly improved walking endurance in PAD. The Centers for Medicare & Medicaid Services recently determined that Medicare would cover 12 wk (36 sessions) of supervised treadmill exercise for patients with PAD.

CONCLUSIONS

Supervised treadmill exercise and home-based walking exercise each improve walking ability in patients with PAD. The availability of insurance coverage for supervised treadmill exercise for patients with PAD will make supervised treadmill exercise more widely available and accessible. Home-based exercise that incorporates behavioral change technique is an effective alternative for patients unwilling or unable to attend 3 supervised exercise sessions per week.

Exercise for intermittent claudication

BACKGROUND

Exercise programmes are a relatively inexpensive, low-risk option compared with other, more invasive therapies for treatment of leg pain on walking (intermittent claudication (IC)). This is the fourth update of a review first published in 1998.

OBJECTIVES

Our goal was to determine whether an exercise programme was effective in alleviating symptoms and increasing walking treadmill distances and walking times in people with intermittent claudication. Secondary objectives were to determine whether exercise was effective in preventing deterioration of underlying disease, reducing cardiovascular events, and improving quality of life.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (last searched 15 November 2016) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 10) via the Cochrane Register of Studies Online, along with trials registries.

SELECTION CRITERIA

Randomised controlled trials of an exercise regimen versus control or versus medical therapy for people with IC due to peripheral arterial disease (PAD). We included any exercise programme or regimen used for treatment of IC, such as walking, skipping, and running. Inclusion of trials was not affected by duration, frequency, or intensity of the exercise programme. Outcome measures collected included treadmill walking distance (time to onset of pain or pain-free walking distance and maximum walking time or maximum walking distance), ankle brachial index (ABI), quality of life, morbidity, or amputation; if none of these was reported, we did not include the trial in this review.

DATA COLLECTION AND ANALYSIS

For this update (2017), RAL and AH selected trials and extracted data independently. We assessed study quality by using the Cochrane 'Risk of bias' tool. We analysed continuous data by determining mean differences (MDs) and 95% confidence intervals (CIs), and dichotomous data by determining risk ratios (RRs) and 95% CIs. We pooled data using a fixed-effect model unless we identified significant heterogeneity, in which case we used a random-effects model. We used the GRADE approach to assess the overall quality of evidence supporting the outcomes assessed in this review.

MAIN RESULTS

We included two new studies in this update and identified additional publications for previously included studies, bringing the total number of studies meeting the inclusion criteria to 32, and involving a total of 1835 participants with stable leg pain. The follow-up period ranged from two weeks to two years. Types of exercise varied from strength training to polestriding and upper or lower limb exercises; supervised sessions were generally held at least twice a week. Most trials used a treadmill walking test for one of the primary outcome measures. The methodological quality of included trials was moderate, mainly owing to absence of relevant information. Most trials were small and included 20 to 49 participants. Twenty-seven trials compared exercise versus usual care or placebo, and the five remaining trials compared exercise versus medication (pentoxifylline, iloprost, antiplatelet agents, and vitamin E) or pneumatic calf compression; we generally excluded people with various medical conditions or other pre-existing limitations to their exercise capacity.Meta-analysis from nine studies with 391 participants showed overall improvement in pain-free walking distance in the exercise group compared with the no exercise group (MD 82.11 m, 95% CI 71.73 to 92.48, P < 0.00001, high-quality evidence). Data also showed benefit from exercise in improved maximum walking distance (MD 120.36 m, 95% CI 50.79 to 189.92, P < 0.0007, high-quality evidence), as revealed by pooling data from 10 studies with 500 participants. Improvements were seen for up to two years.Exercise did not improve the ABI (MD 0.04, 95% CI 0.00 to 0.08, 13 trials, 570 participants, moderate-quality evidence). Limited data were available for the outcomes of mortality and amputation; trials provided no evidence of an effect of exercise, when compared with placebo or usual care, on mortality (RR 0.92, 95% CI 0.39 to 2.17, 5 trials, 540 participants, moderate-quality evidence) or amputation (RR 0.20, 95% CI 0.01 to 4.15, 1 trial, 177 participants, low-quality evidence).Researchers measured quality of life using Short Form (SF)-36 at three and six months. At three months, the domains 'physical function', 'vitality', and 'role physical' improved with exercise; however this was a limited finding, as it was reported by only two trials. At six months, meta-analysis showed improvement in 'physical summary score' (MD 2.15, 95% CI 1.26 to 3.04, P = 0.02, 5 trials, 429 participants, moderate-quality evidence) and in 'mental summary score' (MD 3.76, 95% CI 2.70 to 4.82, P < 0.01, 4 trials, 343 participants, moderate-quality evidence) secondary to exercise. Two trials reported the remaining domains of the SF-36. Data showed improvements secondary to exercise in 'physical function' and 'general health'. The other domains - 'role physical', 'bodily pain', 'vitality', 'social', 'role emotional', and 'mental health' - did not show improvement at six months.Evidence was generally limited in trials comparing exercise versus antiplatelet therapy, pentoxifylline, iloprost, vitamin E, and pneumatic foot and calf compression owing to small numbers of trials and participants.Review authors used GRADE to assess the evidence presented in this review and determined that quality was moderate to high. Although results showed significant heterogeneity between trials, populations and outcomes were comparable overall, with findings relevant to the claudicant population. Results were pooled for large sample sizes - over 300 participants for most outcomes - using reproducible methods.

AUTHORS' CONCLUSIONS

High-quality evidence shows that exercise programmes provided important benefit compared with placebo or usual care in improving both pain-free and maximum walking distance in people with leg pain from IC who were considered to be fit for exercise intervention. Exercise did not improve ABI, and we found no evidence of an effect of exercise on amputation or mortality. Exercise may improve quality of life when compared with placebo or usual care. As time has progressed, the trials undertaken have begun to include exercise versus exercise or other modalities; therefore we can include fewer of the new trials in this update.

Effect of Granulocyte-Macrophage Colony-Stimulating Factor With or Without Supervised Exercise on Walking Performance in Patients With Peripheral Artery Disease: The PROPEL Randomized Clinical Trial

IMPORTANCE

Benefits of granulocyte-macrophage colony-stimulating factor (GM-CSF) for improving walking ability in people with lower extremity peripheral artery disease (PAD) are unclear. Walking exercise may augment the effects of GM-CSF in PAD, since exercise-induced ischemia enhances progenitor cell release and may promote progenitor cell homing to ischemic calf muscle.

OBJECTIVES

To determine whether GM-CSF combined with supervised treadmill exercise improves 6-minute walk distance, compared with exercise alone and compared with GM-CSF alone; to determine whether GM-CSF alone improves 6-minute walk more than placebo and whether exercise improves 6-minute walk more than an attention control intervention.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial with 2 × 2 factorial design. Participants were identified from the Chicago metropolitan area and randomized between January 6, 2012, and December 22, 2016, to 1 of 4 groups: supervised exercise + GM-CSF (exercise + GM-CSF) (n = 53), supervised exercise + placebo (exercise alone) (n = 53), attention control  + GM-CSF (GM-CSF alone) (n = 53), attention control + placebo (n = 51). The final follow-up visit was on August 15, 2017.

INTERVENTIONS

Supervised exercise consisted of treadmill exercise 3 times weekly for 6 months. The attention control consisted of weekly educational lectures by clinicians for 6 months. GM-CSF (250 μg/m2/d) or placebo were administered subcutaneously (double-blinded) 3 times/wk for the first 2 weeks of the intervention.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in 6-minute walk distance at 12-week follow-up (minimum clinically important difference, 20 m). P values were adjusted based on the Hochberg step-up method.

RESULTS

Of 827 persons evaluated, 210 participants with PAD were randomized (mean age, 67.0 [SD, 8.6] years; 141 [67%] black, 82 [39%] women). One hundred ninety-five (93%) completed 12-week follow-up. At 12-week follow-up, exercise + GM-CSF did not significantly improve 6-minute walk distance more than exercise alone (mean difference, -6.3 m [95% CI, -30.2 to +17.6]; P = .61) or more than GM-CSF alone (mean difference, +28.7 m [95% CI, +5.1 to +52.3]; Hochberg-adjusted P = .052). GM-CSF alone did not improve 6-minute walk more than attention control + placebo (mean difference, -1.4 m [95% CI, -25.2 to +22.4]; P = .91). Exercise alone improved 6-minute walk compared with attention control + placebo (mean difference, +33.6 m [95% CI, +9.4 to +57.7]; Hochberg-adjusted P = .02).

CONCLUSIONS AND RELEVANCE

Among patients with PAD, supervised treadmill exercise significantly improved 6-minute walk distance compared with attention control + placebo, whereas GM-CSF did not significantly improve walking performance, either when used alone or when combined with supervised treadmill exercise. These results confirm the benefits of exercise but do not support using GM-CSF to treat walking impairment in patients with PAD.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01408901.

Unloading shoes for intermittent claudication: a randomised crossover trial

Background

The purpose of this study was to assess the functional effects and acceptability of rocker-soled shoes that were designed to relatively “unload” the calf muscles during walking in people with calf claudication due to peripheral arterial disease.

Methods

In this randomised AB/BA crossover trial, participants completed two assessment visits up to two weeks apart. At each visit, participants completed walking tests whilst wearing the unloading shoes or visually-similar control shoes. At the end of the second visit, participants were given either the unloading or control shoes to use in their home environment for 2 weeks, with the instruction to wear them for at least 4 h every day. The primary outcome was 6-min walk distance. We also assessed pain-free walking distance and gait biomechanical variables during usual-pace walking, adverse events, and participants’ opinions about the shoes. Data for continuous outcomes are presented as mean difference between conditions with corresponding 95% confidence interval.

Results

Thirty-four participants (27 males, mean age 68 years, mean ankle-brachial index 0.54) completed both assessment visits. On average, the 6-min walk distance was 11 m greater when participants wore the control shoes (95% CI -5 to 26), whereas mean pain-free walking distance was 7 m greater in the unloading shoes (95% CI -17 to 32). Neither of these differences were statistically significant (p = 0.18 and p = 0.55, respectively). This was despite the unloading shoes reducing peak ankle plantarflexion moment (mean difference 0.2 Nm/kg, 95% CI 0.0 to 0.3) and peak ankle power generation (mean difference 0.6 W/kg, 95% CI 0.2 to 1.0) during pain-free walking. The survey and interview data was mixed, with no clear differences between the unloading and control shoes.

Conclusions

Shoes with modified soles to relatively unload the calf muscles during walking conferred no substantial acute functional benefit over control shoes.

Trial registration

Clinicaltrials.gov, Trial Registration Number: NCT02505503, First registered 22 July 2015.

Electronic supplementary material

The online version of this article (10.1186/s12872-017-0716-x) contains supplementary material, which is available to authorized users.

Motivators and Barriers to Walking in Older Adults With Peripheral Artery Disease

The purpose of the current review is to provide, within the context of social cognitive theory, a current description of behavioral, personal, and environmental factors that motivate or prevent an individual with peripheral artery disease (PAD) from participating in activity. A comprehensive review to explore motivators and barriers to walking in older adults with PAD was performed to help guide development of interventions to increase activity. Several databases were used for the literature review, with inclusion criteria being all study designs with samples of older adults with PAD. From the initial yield of 22 abstracts, and additional hand search, eight publications were used for this review. Social cognitive theory provided a context for understanding barriers and motivators to walking experienced by older adults with PAD. Nurses may contribute to walking self-efficacy with support and motivation. [Journal of Gerontological Nursing, 44(1), 43-50.].

Exercise training for intermittent claudication

OBJECTIVE

The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD).

METHODS

This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium.

RESULTS

Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance.

CONCLUSIONS

Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test.

Self-Care for the Prevention and Management of Cardiovascular Disease and Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association

Self-care is defined as a naturalistic decision-making process addressing both the prevention and management of chronic illness, with core elements of self-care maintenance, self-care monitoring, and self-care management. In this scientific statement, we describe the importance of self-care in the American Heart Association mission and vision of building healthier lives, free of cardiovascular diseases and stroke. The evidence supporting specific self-care behaviors such as diet and exercise, barriers to self-care, and the effectiveness of self-care in improving outcomes is reviewed, as is the evidence supporting various individual, family-based, and community-based approaches to improving self-care. Although there are many nuances to the relationships between self-care and outcomes, there is strong evidence that self-care is effective in achieving the goals of the treatment plan and cannot be ignored. As such, greater emphasis should be placed on self-care in evidence-based guidelines.

Endothelial Cell Inflammation and Antioxidant Capacity are Associated With 6-Minute Walk Performance in Patients With Symptomatic Peripheral Artery Disease

We determined whether 6-minute walk total distance and pain-free distance were associated with circulating biomarkers of antioxidant capacity and inflammation and with cultured endothelial cell inflammation, oxidative stress, and apoptosis in 251 patients with symptomatic peripheral artery disease (PAD). In multivariate analyses, pain-free distance during the 6-minute walk test was negatively associated with dyslipidemia ( P < .001), chronic kidney disease ( P = .004), and transient transfection, nuclear factor κ-Light-Chain-Enhancer of activated B (NF-κB) cultured endothelial cells ( P = .007) and was positively associated with height ( P = .008). Furthermore, total distance walked during the 6-minute walk test was negatively associated with cultured endothelial cell NF-κB ( P < .001), coronary artery disease ( P = .009), and body mass index ( P = .022) and was positively associated with ankle-brachial index ( P < .001), male sex ( P < .001), and hydroxyl radical antioxidant capacity ( P < .001). The 6-minute walk performance in symptomatic patients with PAD was associated with vascular biomarkers, as walking distances were negatively associated with cultured endothelial cell inflammation and positively associated with circulating antioxidant capacity. The clinical implication is that behavioral interventions designed to alleviate endothelial cell inflammation and increase circulating antioxidant capacity, such as exercise and antioxidant intake, may improve ambulation of patients with PAD during submaximal exercise that is typically performed during daily activities.

Dose of physical activity, physical functioning and disability risk in mobility-limited older adults: Results from the LIFE study randomized trial

Understanding the minimal dose of physical activity required to achieve improvement in physical functioning and reductions in disability risk is necessary to inform public health recommendations. To examine the effect of physical activity dose on changes in physical functioning and the onset of major mobility disability in The Lifestyle Interventions and Independence for Elders (LIFE) Study. We conducted a multicenter single masked randomized controlled trial that enrolled participants in 2010 and 2011 and followed them for an average of 2.6 years. 1,635 sedentary men and women aged 70-89 years who had functional limitations were randomized to a structured moderate intensity walking, resistance, and flexibility physical activity program or a health education program. Physical activity dose was assessed by 7-day accelerometry and self-report at baseline and 24 months. Outcomes included the 400 m walk gait speed, the Short Physical Performance Battery (SPPB), assessed at baseline, 6, 12, and 24 months, and onset of major mobility disability (objectively defined by loss of ability to walk 400 m in 15 min). When the physical activity arm or the entire sample were stratified by change in physical activity from baseline to 24 months, there was a dose-dependent increase in the change in gait speed and SPPB from baseline at 6, 12, and 24 months. In addition, the magnitude of change in physical activity over 24 months was related to the reduction in the onset of major mobility disability (overall P < 0.001) (highest versus the lowest quartile of physical activity change HR 0.23 ((95% CI:0.10-0.52) P = 0.001) in the physical activity arm. We observed a dose-dependent effect of objectively monitored physical activity on physical functioning and onset of major mobility disability. Relatively small increases (> 48 minutes per week) in regular physical activity participation had significant and clinically meaningful effects on these outcomes.

TRIAL REGISTRATION

ClinicalsTrials.gov NCT00116194.