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

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.

Factors Associated With Ambulatory Activity in De Novo Parkinson Disease

BACKGROUND AND PURPOSE

Objective ambulatory activity during daily living has not been characterized for people with Parkinson disease prior to initiation of dopaminergic medication. Our goal was to characterize ambulatory activity based on average daily step count and examine determinants of step count in nonexercising people with de novo Parkinson disease.

METHODS

We analyzed baseline data from a randomized controlled trial, which excluded people performing regular endurance exercise. Of 128 eligible participants (mean ± SD = 64.3 ± 8.6 years), 113 had complete accelerometer data, which were used to determine daily step count. Multiple linear regression was used to identify factors associated with average daily step count over 10 days. Candidate explanatory variable categories were (1) demographics/anthropometrics, (2) Parkinson disease characteristics, (3) motor symptom severity, (4) nonmotor and behavioral characteristics, (5) comorbidities, and (6) cardiorespiratory fitness.

RESULTS

Average daily step count was 5362 ± 2890 steps per day. Five factors explained 24% of daily step count variability, with higher step count associated with higher cardiorespiratory fitness (10%), no fear/worry of falling (5%), lower motor severity examination score (4%), more recent time since Parkinson disease diagnosis (3%), and the presence of a cardiovascular condition (2%).

DISCUSSION AND CONCLUSIONS

Daily step count in nonexercising people recruited for this intervention trial with de novo Parkinson disease approached sedentary lifestyle levels. Further study is warranted for elucidating factors explaining ambulatory activity, particularly cardiorespiratory fitness, and fear/worry of falling. Clinicians should consider the costs and benefits of exercise and activity behavior interventions immediately after diagnosis of Parkinson disease to attenuate the health consequences of low daily step count.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A170).

The influence of pain-related beliefs on physical activity and health attitudes in patients with claudication: A pilot study

We examined how pain beliefs are related to symptom severity, expectations of risk/benefits, and baseline physical activity among claudicants. Eligible patients at the Michael E DeBakey Veterans Affairs Medical Center were administered questionnaires that measured: fear-avoidance beliefs (Fear-Avoidance Beliefs Questionnaire [FABQ]), walking impairment, baseline physical activity, claudication type, and risk/benefit attitudes. Among 20 participants, the median age was 69 years (IQR: 66–75). In our efforts to understand how fear-avoidance beliefs influenced physical activity among people with claudication, we found that 12 out of 19 participants (63%) thought that the primary etiology of their pain was walking, while 18 (out of 20) (90%) people thought that walking would exacerbate their leg symptoms – suggesting that there was some confusion regarding the effects of walking on claudication. Those who expected that walking would benefit their symptoms more than surgery reported fewer fear-avoidance beliefs ( p=0.01), but those who believed that walking would make their leg pain worse expected greater benefit from surgery ( p=0.02). As symptom severity increased, fear-avoidance beliefs also increased ( p=0.001). The association between symptom severity and fear-avoidance beliefs indicates that as pain or impairment increases, the likelihood of avoiding behaviors that are thought to cause pain might also increase. Accounting for pain-related beliefs when recommending physical activity for claudication should be considered.

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health. These guidelines, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality cardiovascular care.

In response to reports from the Institute of Medicine1 ,2 and a mandate to evaluate new knowledge and maintain relevance at the point of care, the ACC/AHA Task Force on Clinical Practice Guidelines (Task Force) modified its methodology.3 –5 The relationships among guidelines, data standards, appropriate use criteria, and performance measures are addressed elsewhere.5

Predicting long-term prognosis in stable peripheral artery disease with baseline functional capacity estimated by the Duke Activity Status Index

BACKGROUND

The ability of a simple self-assessment tool for estimated functional capacity to predict long-term prognosis in patients with established peripheral artery disease (PAD) is unknown. We investigate whether subjective measurement of functional capacity estimated by using the Duke Activity Status Index (DASI) questionnaire predicts long-term prognosis in patients with established PAD.

METHODS

We administered the DASI questionnaire to 771 stable patients with established PAD who underwent elective diagnostic coronary angiography with 5-year follow-up all-cause mortality.

RESULTS

Two hundred ten patients (27%) died over a 5-year follow-up. The lowest DASI score was associated with a 3.2-fold increased risk of 5-year all-cause mortality (unadjusted hazard ratio 3.23, 95% CI 2.19-4.75, P<.001). After adjustments for traditional risk factors, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and lowest DASI score remained predictive of 5-year all-cause mortality (adjusted hazard ratio 2.09, 95% CI 1.36-3.23, P<.001). Interestingly, the lowest DASI score remained to predict 5-year all-cause mortality regardless of each PAD diagnosis subtype (including lower extremity, non-lower extremity, or carotid artery PAD), although the mortality risk was attenuated when incorporating heart disease severity in the non-lower extremity group.

CONCLUSIONS

A simple self-assessment tool of functional capacity provides an independent and incremental prognosis value for long-term adverse clinical events in stable patients with established PAD beyond each PAD diagnostic subtype.

Physical activity behavior change for older veterans after dysvascular amputation

OBJECTIVE

Determine the feasibility of using a physical-activity behavior-change (PABC) intervention for increasing physical activity and reducing disability in Veterans 1-5years following dysvascular lower-limb amputation (LLA).

DESIGN

Cross-over, feasibility trial SETTING: VA Geriatric Research Education and Clinical Center and Veterans Homes PARTICIPANTS: 32 Veterans with dysvascular LLA (1-5years after major LLA) INTERVENTION: The home-based study, using telerehabilitation technology, is intended to reduce participant burden by removing transportation and time barriers. Participants will be randomized into two participation periods of three months (Months 1-3 and 4-6). PABC intervention will occur Months 1-3 for GROUP1 and Months 4-6 for GROUP2. During PABC Intervention, participants engage in weekly video interaction with a physical therapist, who uses a collaborative approach to develop self-monitoring, barrier identification, problem solving and action planning skills to improve physical activity. GROUP2 will participate in a no physical activity intervention, attention control in Months 1-3. GROUP1 will have a no contact, intervention "wash-out" period in Months 4-6.

MAIN OUTCOME MEASURES

Feasibility will be determined using measures of 1) participant retention, 2) dose goal attainment, 3) participant acceptability, 4) safety, and 5) initial effect size. Effect size will be based on accelerometer-based physical activity and self-report disability using the Late-Life Function and Disability Index.

CONCLUSIONS

This study focuses on a prevalent and understudied population with low physical activity and high levels of disability due to dysvascular LLA. The results of this study will guide future development of targeted rehabilitation research to improve long term physical activity and disability outcomes.

Predictors of Improved Walking after a Supervised Walking Exercise Program in Men and Women with Peripheral Artery Disease

We compared the changes in ambulatory outcomes between men and women with symptomatic peripheral arterial disease (PAD) following completion of a supervised, on-site, treadmill exercise program, and we determined whether exercise training variables and baseline clinical characteristics were predictive of changes in ambulatory outcomes in men and women. Twenty-three men and 25 women completed the supervised exercise program, consisting of intermittent walking to mild-to-moderate claudication pain for three months. Men and women significantly increased claudication onset time (COT) (p < 0.001 and p < 0.01, resp.) and peak walking time (PWT) (p < 0.001 for each group). However, change in PWT was less in women (54%) than in men (77%) (p < 0.05). Neither group significantly changed 6-minute walk distance (6MWD). In women, baseline COT was the only predictor for the change in COT (p = 0.007) and the change in PWT (p = 0.094). In men, baseline COT (p < 0.01) and obesity (p < 0.10) were predictors for the change in COT, and obesity was the only predictor for the change in PWT (p = 0.002). Following a supervised, on-site, treadmill exercise program, women had less improvement in PWT than men, and neither men nor women improved submaximal, overground 6MWD. Furthermore, obese men and patients with lower baseline COT were least responsive to supervised exercise. This trial is registered with ClinicalTrial.gov, unique identifier: NCT00618670.

Effect of diabetes mellitus on walking distance parameters after supervised exercise therapy for intermittent claudication: A systematic review

Some believe that certain patients with intermittent claudication may be unsuitable for supervised exercise therapy (SET), based on the presence of comorbidities and the possibly increased risks. We conducted a systematic review (MEDLINE, EMBASE and CENTRAL) to summarize evidence on the potential influence of diabetes mellitus (DM) on the response to SET. Randomized and nonrandomized studies that investigated the effect of DM on walking distance after SET in patients with IC were included. Considered outcome measures were maximal, pain-free and functional walking distance (MWD, PFWD and FWD). Three articles met the inclusion criteria ( n = 845). In one study, MWD was 111 meters (128%) longer in the non-DM group compared to the DM group after 3 months of follow-up ( p = 0.056). In a second study, the non-DM group demonstrated a significant increase in PFWD (114 meters, p ⩽ 0.05) after 3 months of follow-up, whereas there was no statistically significant increase for the DM group (54 meters). On the contrary, the largest study of this review did not demonstrate any adverse effect of DM on MWD and FWD after SET. In conclusion, the data evaluating the effects of DM on SET were inadequate to determine if DM impairs the exercise response. While trends in the data do not suggest an impairment, they are not conclusive. Practitioners should consider this limitation when making clinical decisions.

Efficacy of brief behavioral counselling by allied health professionals to promote physical activity in people with peripheral arterial disease (BIPP): study protocol for a multi-center randomized controlled trial

Background

Physical activity is recommended for people with peripheral arterial disease (PAD), and can improve walking capacity and quality of life; and reduce pain, requirement for surgery and cardiovascular events. This trial will assess the efficacy of a brief behavioral counselling intervention delivered by allied health professionals to improve physical activity in people with PAD.

Methods

This is a multi-center randomised controlled trial in four cities across Australia. Participants (N = 200) will be recruited from specialist vascular clinics, general practitioners and research databases and randomised to either the control or intervention group. Both groups will receive usual medical care, a written PAD management information sheet including advice to walk, and four individualised contacts from a protocol-trained allied health professional over 3 months (weeks 1, 2, 6, 12). The control group will receive four 15-min telephone calls with general discussion about PAD symptoms and health and wellbeing. The intervention group will receive behavioral counselling via two 1-h face-to-face sessions and two 15-min telephone calls. The counselling is based on the 5A framework and will promote interval walking for 3 × 40 min/week. Assessments will be conducted at baseline, and 4, 12 and 24 months by staff blinded to participant allocation. Objectively assessed outcomes include physical activity (primary), sedentary behavior, lower limb body function, walking capacity, cardiorespiratory fitness, event-based claudication index, vascular interventions, clinical events, cardiovascular function, circulating markers, and anthropometric measures. Self-reported outcomes include physical activity and sedentary behavior, walking ability, pain severity, and health-related quality of life. Data will be analysed using an intention-to-treat approach. An economic evaluation will assess whether embedding the intervention into routine care would likely be value for money. A cost-effectiveness analysis will estimate change in cost per change in activity indicators due to the intervention, and a cost-utility analysis will assess change in cost per quality-adjusted life year. A full uncertainty analysis will be undertaken, including a value of information analysis, to evaluate the economic case for further research.

Discussion

This trial will evaluate the efficacy and cost-effectiveness of a brief behavioral counselling intervention for a common cardiovascular disease with significant burden.

Trial registration

ACTRN 12614000592640 Australian New Zealand Clinical Trials Registry. Registration Date 4 June 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3801-7) contains supplementary material, which is available to authorized users.

Walking performance is positively correlated to calf muscle fiber size in peripheral artery disease subjects, but fibers show aberrant mitophagy: an observational study

BACKGROUND

Patients with lower extremity peripheral artery disease (PAD) have decreased mobility, which is not fully explained by impaired blood supply to the lower limb. Additionally, reports are conflicted regarding fiber type distribution patterns in PAD, but agree that skeletal muscle mitochondrial respiration is impaired.

METHODS

To test the hypothesis that reduced muscle fiber oxidative activity and type I distribution are negatively associated with walking performance in PAD, calf muscle biopsies from non-PAD (n = 7) and PAD participants (n = 26) were analyzed immunohistochemically for fiber type and size, oxidative activity, markers of autophagy, and capillary density. Data were analyzed using analysis of covariance.

RESULTS

There was a wide range in fiber type distribution among subjects with PAD (9-81 % type I fibers) that did not correlate with walking performance. However, mean type I fiber size correlated with 4-min normal- and fastest-paced walk velocity (r = 0.4940, P = 0.010 and r = 0.4944, P = 0.010, respectively). Although intensity of succinate dehydrogenase activity staining was consistent with fiber type, up to 17 % of oxidative fibers were devoid of mitochondria in their cores, and the core showed accumulation of the autophagic marker, LC3, which did not completely co-localize with LAMP2, a lysosome marker.

CONCLUSIONS

Calf muscle type I fiber size positively correlates with walking performance in PAD. Accumulation of LC3 and a lack of co-localization of LC3 with LAMP2 in the area depleted of mitochondria in PAD fibers suggests impaired clearance of damaged mitochondria, which may contribute to reduced muscle oxidative capacity. Further study is needed to determine whether defective mitophagy is associated with decline in function over time, and whether interventions aimed at preserving mitochondrial function and improving autophagy can improve walking performance in PAD.

Long Term Home-Based Exercise is Effective to Reduce Blood Pressure in Low Income Brazilian Hypertensive Patients: A Controlled Trial

INTRODUCTION

Home-based exercise programs may increase adherence to physical activity among groups with poor access to exercise facilities. However, their effectiveness to lower blood pressure of hypertensive patients remains undefined.

AIMS

This controlled clinical trial investigated the influence of a home-based exercise program upon blood pressure, blood metabolic profile, and physical fitness in a Brazilian cohort of low income patients diagnosed with hypertension.

METHODS

Twenty-nine patients (22 women, age: 53 ± 11 years) underwent 16 months of home-based exercise, including 30 min of moderate intensity walking and stretching exercises. Fourteen patients (9 women, age: 48 ± 5 years) composed a non-exercise control group. Primary outcomes were assessed each two months.

RESULTS

Body mass (3.6 ± 0.2 kg; P = 0.03) and sum of skinfolds (3.0 ± 1.2 cm; P = 0.04) increased in controls vs. baseline. Mean compliance to home-based exercise was 83 ± 7 %, which induced significant improvements from baseline vs. controls in body mass (-5.4 ± 2.0 kg; P = 0.04), body fat (-4.7 ± 0.3 %; P = 0.03), waist circumference (-6.1 ± 1.2 cm; P = 0.03), sum of skinfolds (-14.8 ± 3.7; P = 0.02); aerobic efficiency reflected by slopes of relationships between heart rate and workload (-0.05 ± 0.01; P = 0.05), trunk flexibility (7.8 ± 1.7 cm; P = 0.02), HDL (1.8 ± 0.9 mg/dL; P = 0.04), triglycerides (-12.3 ± 1.0 mg/dL; P = 0.03), and glucose (-6.9 ± 2.9 mg/dL; P = 0.05). Systolic and diastolic BP decreased until the sixth month of intervention vs. baseline and controls, remaining stable at lower levels thereafter (systolic blood pressure: -4.5 ± 0.3 mmHg; P = 0.03; diastolic blood pressure: -2.5 ± 0.6 mmHg; P = 0.05).

CONCLUSIONS

Low income hypertensive patients complied with a long-term home-based exercise program, which was effective for improving their functional capacity, blood metabolic profile, and blood pressure.

Peripheral Artery Disease: Evolving Role of Exercise, Medical Therapy, and Endovascular Options

The prevalence of peripheral artery disease (PAD) continues to increase worldwide. It is important to identify patients with PAD because of the increased risk of myocardial infarction, stroke, and cardiovascular death and impaired quality of life because of a profound limitation in exercise performance and the potential to develop critical limb ischemia. Despite effective therapies to lower the cardiovascular risk and prevent progression to critical limb ischemia, patients with PAD continue to be under-recognized and undertreated. The management of PAD patients should include an exercise program, guideline-based medical therapy to lower the cardiovascular risk, and, when revascularization is indicated, an "endovascular first" approach. The indications and strategic choices for endovascular revascularization will vary depending on the clinical severity of the PAD and the anatomic distribution of the disease. In this review, we discuss an evidence-based approach to the management of patients with PAD.

Recruiting African Americans with peripheral artery disease for a behavioral intervention trial

We report recruitment strategies for an NIH-funded trial focused on African Americans with peripheral artery disease (PAD). We present complete recruitment efforts for this 1-year trial, 5-year study. Eligibility included the following: African American, a resting ankle–brachial index (ABI) ⩽ 0.99, a short physical performance battery (SPPB) score of 10 or lower, English speaking, telephone access, and absence of coronary ischemia during a submaximal treadmill test. Recruitment included mailings of brochures to zip codes in which more than 50% of residents were African American, advertisements, community events, and physician/clinic referrals. We telephone-screened 3511 persons, of whom 792 did not recall the method by which they learned about the study. We randomized 174 participants. Mailings yielded the highest percentage of randomized participants ( n=60, 34.4%), followed by television advertisements ( n=42, 24.1%), followed by community events ( n=24, 13.8%). In conclusion, to recruit African Americans with PAD for a clinical trial, investigators should consider mailings of brochures, television advertisements, and community events. ClinicalTrials.gov Identifier: NCT01321086

How Well Do Randomized Controlled Trials Reflect Standard Care: A Comparison between Scientific Research Data and Standard Care Data in Patients with Intermittent Claudication undergoing Supervised Exercise Therapy

OBJECTIVE

The aim of the present study was to assess the degree and impact of patient selection of patients with intermittent claudication undergoing supervised exercise therapy in Randomized Controlled Trials (RCTs) by describing commonly used exclusion criteria, and by comparing baseline characteristics and treatment response measured as improvement in maximum walking distance of patients included in RCTs and patients treated in standard care.

METHODS

We compared data from RCTs with unselected standard care data. First, we systematically reviewed RCTs that investigated the effect of supervised exercise therapy in patients with intermittent claudication. For each of the RCTs, we extracted and categorized the eligibility criteria and their justifications. To assess whether people in RCTs (n = 1,440) differed from patients treated in daily practice (n = 3,513), in terms of demographics, comorbidity and walking capacity, we assessed between group-differences using t-tests. To assess differences in treatment response, we compared walking distances at three and six months between groups using t-tests. Differences of ≥15% were set as a marker for a clinically relevant difference.

RESULTS

All 20 included RCTs excluded large segments of patients with intermittent claudication. One-third of the RCTs eligibility criteria were justified. Despite, the numerous eligibility criteria, we found that baseline characteristics were largely comparable. A statistically significant and (borderline) clinically relevant difference in treatment response after three and six months between trial participants and standard care patients was found. Improvements in maximum walking distance after three and six months were significantly and clinically less in trial participants.

CONCLUSIONS

The finding that baseline characteristics of patients included in RCTs and patients treated in standard care were comparable, may indicate that RCT eligibility criteria are used implicitly by professionals when referring patients to standard physiotherapy care. The larger treatment response reported in standard physiotherapy care compared to clinical trials, might suggest that scientific studies underestimate the benefits of supervised exercise therapy in patients with intermittent claudication.

Thermotherapy reduces blood pressure and circulating endothelin-1 concentration and enhances leg blood flow in patients with symptomatic peripheral artery disease

Leg thermotherapy (TT) application reduces blood pressure (BP) and increases both limb blood flow and circulating levels of anti-inflammatory mediators in healthy, young humans and animals. The purpose of the present study was to determine the impact of TT application using a water-circulating garment on leg and systemic hemodynamics and on the concentrations of circulating cytokines and vasoactive mediators in patients with symptomatic peripheral artery disease (PAD). Sixteen patients with PAD and intermittent claudication (age: 63 ± 9 yr) completed three experimental sessions in a randomized order: TT, control intervention, and one exercise testing session. The garment was perfused with 48°C water for 90 min in the TT session and with 33°C water in the control intervention. A subset of 10 patients also underwent a protocol for the measurement of blood flow in the popliteal artery during 90 min of TT using phase-contrast MRI. Compared with the control intervention, TT promoted a significant reduction in systolic (∼11 mmHg) and diastolic (∼6 mmHg) BP (P < 0.05) that persisted for nearly 2 h after the end of the treatment. The serum concentration of endothelin-1 (ET-1) was significantly lower 30 min after exposure to TT (Control: 2.3 ± 0.1 vs. TT: 1.9 ± 0.09 pg/ml, P = 0.026). In addition, TT induced a marked increase in peak blood flow velocity (∼68%), average velocity (∼76%), and average blood flow (∼102%) in the popliteal artery (P < 0.01). These findings indicate that TT is a practical and effective strategy to reduce BP and circulating ET-1 concentration and enhance leg blood flow in patients with PAD.

Intensive walking exercise for lower extremity peripheral arterial disease: A systematic review and meta-analysis

BACKGROUND

Supervised treadmill exercise is the recommended therapy for peripheral arterial disease (PAD) patients with intermittent claudication (IC). However, most PAD patients do not exhibit typical symptoms of IC. The aim of the present study was to explore the efficacy and safety of intensive walking exercise in PAD patients with and without IC.

METHODS

The PubMed, Embase and Cochrane Library databases were systematically searched. Randomized controlled trials comparing the effects of intensive walking exercise with usual care in patients with PAD were included for systematic review and meta-analysis.

RESULTS

Eighteen trials with 1200 patients were eligible for the present analysis. Compared with usual care, intensive walking exercise significantly improved the maximal walking distance (MWD), pain-free walking distance, and the 6-min walking distance in patients with PAD (P < 0.00001 for all). Subgroup analyses indicated that a lesser improvement in MWD was observed in the subgroup with more diabetes patients, and that the subgroup with better baseline walking ability exhibited greater improvement in walking performance. In addition, similar improvements in walking performance were observed for exercise programs of different durations and modalities. No significant difference was found in adverse events between the intensive walking and usual care groups (relative risk 0.84; 95% confidence interval 0.51, 1.39; P = 0.50).

CONCLUSIONS

Regardless of exercise length and modality, regularly intensive walking exercise improves walking ability in PAD patients more than usual care. The presence of diabetes may attenuate the improvements in walking performance in patients with PAD following exercise.

Physical exercise and quantitative lower limb collateral function

Objective

This study tested the hypothesis that global physical activity and physical performance parameters are directly related to invasively obtained left superficial femoral artery (SFA) collateral flow index (CFI).

Background

So far, the association between different measures of physical exercise activity and quantitative lower limb collateral function has not been investigated.

Methods

The primary study end point was pressure-derived CFI as obtained during a 3 min left SFA balloon occlusion. CFI is the ratio of simultaneously recorded mean SFA distal occlusive pressure divided by mean aortic pressure, both subtracted by central venous pressure. As independent variables, the items of the Global Physical Activity Questionnaire (GPAQ) and physical exercise performance (maximal workload in watts) as achieved during a bicycle or treadmill exercise test were determined. The secondary study end point was transcutaneous left calf partial oxygen pressure (PO₂ in mm Hg) divided by transcutaneous PO₂ at a non-ischaemic reference site as obtained simultaneously to CFI measurement.

Results

Of the 110 study patients undergoing diagnostic coronary angiography, 79 belonged to the group without and 31 with engagement in regular intensive leisure time physical activity according to GPAQ. Left SFA CFI tended to be lower in the group without than with intensive leisure time physical activity: 0.514 ±0.141 vs 0.560 ±0.184 (p =0.0566). Transcutaneous PO₂ index was associated with simultaneous left SFA CFI: CFI =018 +0.57 PO₂ index; p<0.0001. Maximal physical workload was directly associated with left SFA CFI: CFI =0.40 +0.0009 maximal workload; p =0.0044.

Conclusions

Quantitative left SFA collateral function is directly reflected by maximal physical workload as achieved during an exercise test.

Trial registration number

NCTO02063347.

INFLUENCE OF DIABETES ON AMBULATION AND INFLAMMATION IN MEN AND WOMEN WITH SYMPTOMATIC PERIPHERAL ARTERY DISEASE

•

Diabetes and sex were correlated with ambulation and inflammation in patients with claudication.

•

Men with diabetes have worse ambulation than men without diabetes.

•

Women with diabetes have greater inflammation than women free of diabetes.

•

Men and women with diabetes have evidence for high levels of angiogenic inhibition.

Objective

To determine whether diabetes and sex were factors associated with ambulatory function, endothelial cell inflammation, oxidative stress, and apoptosis, and with circulating biomarkers of inflammation and antioxidant capacity in patients with peripheral artery disease (PAD) and claudication.

Materials/Methods

Ambulatory function of 180 symptomatic men and women with PAD was assessed during a graded maximal treadmill test, 6-minute walk test, and 4-meter walk test. Patients were further characterized on endothelial effects of circulating factors present in the sera using a cell culture-based bioassay on primary human arterial endothelial cells, and on circulating inflammatory and vascular biomarkers.

Results

Men and women with diabetes had greater prevalence (p = 0.007 and p = 0.015, respectively) of coronary artery disease (CAD) than patients without diabetes. To assure that this difference did not influence planned comparisons, the data set was stratified on CAD. Diabetic men with CAD had a lower peak walking time (PWT) during the treadmill test and a slower 4-meter gait speed compared to non-diabetic men with CAD (p < 0.05). Diabetic women with CAD had a lower PWT compared to their non-diabetic counterparts (p < 0.01). Additionally, diabetic men with CAD had higher pigment epithelium-derived factor (p < 0.05) than their non-diabetic counterparts, and diabetic women with CAD had higher leptin (p < 0.01) and interleukin-8 levels (p < 0.05).

Conclusions

In patients with PAD, diabetic men and women with CAD had more severe claudication than their non-diabetic counterparts, as measured by shorter PWT, and the men had further ambulatory impairment manifested by slower 4-meter gait speed. Furthermore, the diabetic patients with CAD had elevations in interleukin-8, leptin, and PEDF.

The effect of physical activity on cardiometabolic health and inflammation in treated HIV infection

BACKGROUND

In HIV-uninfected populations, physical activity decreases mortality and inflammation. Inflammation is a potential cause of comorbidities in HIV+ adults, the evidence examining the effect of physical activity on cardiometabolic health is limited. This analysis examines the relationship between physical activity, cardiometabolic health and inflammation.

METHODS

We conducted a nested study within the SATURN-HIV trial in which 147 HIV+ adults were randomized to 10 mg daily rosuvastatin or placebo. Measures of physical activity, cardiometabolic health, inflammation and vascular disease (carotid artery intima media thickness and computed tomography-acquired measures pericardial fat volume) were assessed at baseline and through 96 weeks. Spearman correlations and multivariable analyses were used to explore relationships between physical activity, cardiometabolic health and inflammation.

RESULTS

Median age (Q1, Q3) was 46 (40.4, 52.7) years, 80% were male, 69% were African American and 46% were on protease inhibitors. Baseline median physical activity was 44 min per week (0, 150), 24% of participants performed greater than 150 min per week. At baseline, physical activity correlated with several markers of cardiometabolic health and inflammation (all P≤0.05). Over all time points median physical activity was independently associated with carotid distensibility (β=2.53; P=0.008), pericardial fat volume (β=-6.13; P=0.001) and interleukin-6 (β=-0.468; P<0.001).

CONCLUSIONS

Physical activity is associated with vascular disease, endothelial function, and may be an adjuvant to decreasing comorbidities in HIV+ adults. Further studies should examine long-term effects of physical activity on cardiometabolic health and inflammation in this population. Clinicaltrials.gov NCT01218802.

Contemporary medical management of peripheral arterial disease: a focus on risk reduction and symptom relief for intermittent claudication

Peripheral arterial disease (PAD) is primarily caused by progressive systemic atherosclerosis manifesting in the lower extremities. This review addresses the epidemiology, clinical presentation and evaluation, and medical management of PAD, with a focus on intermittent claudication. Key advances in the recognition of cardiovascular risk in asymptomatic individuals with mildly abnormal ankle-brachial index, newer reflections on exercise therapy, and a review of established and investigational agents for the treatment of symptomatic PAD, such as cilostazol, statins, and angiotensin-converting enzyme inhibitors, are highlighted.

Sex-specific predictors of improved walking with step-monitored, home-based exercise in peripheral artery disease

The aim of this study was to determine whether baseline clinical characteristics and the duration and intensity of ambulation during our step-monitored home-based exercise program were predictive of changes in ambulatory outcomes at completion of the program in symptomatic patients with peripheral artery disease (PAD). Twenty-two men (ankle-brachial index (ABI) = 0.71 ± 0.19) and 24 women (ABI = 0.66 ± 0.23) completed the home exercise program, consisting of intermittent walking to mild-to-moderate claudication pain for 3 months. Ambulatory outcome measures were peak walking time (PWT) and claudication onset time (COT) during a treadmill test, and the distance recorded during a 6-minute walk distance test (6MWD). Men experienced significant increases (p<0.01) in COT, PWT, and 6MWD following the home exercise program, and women had significant increases in 6MWD (p<0.01) and PWT (p<0.05). In women, average exercise cadence during the home exercise sessions was the only predictor that entered the model for change in COT (p=0.082), and was the first predictor in the model for change in PWT (p=0.029) and 6MWD (p=0.006). In men, the ABI was the only predictor that entered the model for change in 6MWD (p=0.002), and ABI was a predictor along with metabolic syndrome in the model for change in COT (p=0.003). No variables entered the model for change in PWT. Faster ambulatory cadence during the step-monitored home-based exercise program may predict greater improvements in ambulatory function in women, whereas having less severe PAD and comorbid burden at baseline may predict greater improvements in ambulatory function in men. ClinicalTrials.gov Identifier: NCT00618670.

Association of 6-Minute Walk Performance and Physical Activity With Incident Ischemic Heart Disease Events and Stroke in Peripheral Artery Disease

BACKGROUND

We determined whether poorer 6-minute walk performance and lower physical activity levels are associated with higher rates of ischemic heart disease (IHD) events in people with lower extremity peripheral artery disease (PAD).

METHODS AND RESULTS

Five hundred ten PAD participants were identified from Chicago-area medical centers and followed prospectively for 19.0±9.5 months. At baseline, participants completed the 6-minute walk and reported number of blocks walked during the past week (physical activity). IHD events were systematically adjudicated and consisted of new myocardial infarction, unstable angina, and cardiac death. For 6-minute walk, IHD event rates were 25/170 (14.7%) for the third (poorest) tertile, 10/171 (5.8%%) for the second tertile, and 6/169 (3.5%) for the first (best) tertile (P=0.003). For physical activity, IHD event rates were 21/154 (13.6%) for the third (poorest) tertile, 15/174 (8.6%) for the second tertile, and 5/182 (2.7%) for the first (best) tertile (P=0.001). Adjusting for age, sex, race, smoking, body mass index, comorbidities, and physical activity, participants in the poorest 6-minute walk tertile had a 3.28-fold (95% CI 1.17 to 9.17, P=0.024) higher hazard for IHD events, compared with those in the best tertile. Adjusting for confounders including 6-minute walk, participants in the poorest physical activity tertile had a 3.72-fold (95% CI 1.24 to 11.19, P=0.019) higher hazard for IHD events, compared with the highest tertile.

CONCLUSIONS

Six-minute walk and physical activity predict IHD event rates in PAD. Further study is needed to determine whether interventions that improve 6-minute walk, physical activity, or both can reduce IHD events in PAD.

Pain-free treadmill exercise for patients with intermittent claudication: Are there gender differences?

Intermittent claudication, a common symptom of peripheral arterial disease, results in insufficient blood flow and oxygen supply to lower extremity muscles. Compared to men, women with peripheral arterial disease have a higher rate of mobility loss with peripheral arterial disease due to poorer lower extremity functioning. This study evaluates the effect of supervised pain-free treadmill exercise on improving performance in women with intermittent claudication due to peripheral arterial disease in comparison to men. A total of 26 participants (women, n = 9, 34.62%; mean age = 67.58 ± 5.59 years; averaging 23.46 ± 3.91 visits and 10.46 ± 0.99 weeks in the program) diagnosed with peripheral arterial disease, with symptoms of intermittent claudication, partook in a 45 min treadmill walk, twice per week, below the participant's minimal pain threshold. Female participants' change scores showed 752%, 278% and 115% improvement in mean walking distance, duration and rate, respectively. Men improved 334%, 149% and 80%, respectively. Significant differences (p < 0.05) in pre and post measurements within each group support positive outcomes. No significant differences between groups were observed (Cohen's d effect size > 0.80). Our results suggest that women reap similar benefits from this low-intensity treadmill program in comparison to men.

Endovascular intervention for peripheral artery disease

Advances in endovascular therapies during the past decade have broadened the options for treating peripheral vascular disease percutaneously. Endovascular treatment offers a lower risk alternative to open surgery in many patients with multiple comorbidities. Noninvasive physiological tests and arterial imaging precede an endovascular intervention and help localize the disease and plan the procedure. The timing and need for revascularization are broadly related to the 3 main clinical presentations of claudication, critical limb ischemia, and acute limb ischemia. Many patients with claudication can be treated by exercise and medical therapy. Endovascular procedures are considered when these fail to improve quality of life and function. In contrast, critical limb ischemia and acute limb ischemia threaten the limb and require more urgent revascularization. In general, endovascular treatments have greater long-term durability for aortoiliac disease than femoral popliteal disease. Infrapopliteal revascularization is generally reserved for critical and acute limb ischemia. Balloon angioplasty and stenting are the mainstays of endovascular therapy. New well-tested innovations include drug-eluting stents and drug-coated balloons. Adjunctive devices for crossing chronic total occlusions or debulking plaque with atherectomy are less rigorously studied and have niche roles. Patients receiving endovascular procedures need a structured surveillance plan for follow-up care. This includes intensive treatment of cardiovascular risk factors to prevent myocardial infarction and stroke, which are the main causes of death. Limb surveillance aims to identify restenosis and new disease beyond the intervened segments, both of which may jeopardize patency and lead to recurrent symptoms, functional impairment, or a threatened limb.

Lower extremity manifestations of peripheral artery disease: the pathophysiologic and functional implications of leg ischemia

Lower extremity peripheral artery disease (PAD) is frequently underdiagnosed, in part because of the wide variety of leg symptoms manifested by patients with PAD and in part because of the high prevalence of asymptomatic PAD. In primary care medical practices, 30% to 60% of patients with PAD report no exertional leg symptoms and ≈45% to 50% report exertional leg symptoms that are not consistent with classic intermittent claudication. The prevalence and extent of functional impairment and functional decline in PAD may also be underappreciated. Functional impairment and functional decline are common in PAD, even among those who are asymptomatic. Lower extremity ischemia is also associated with pathophysiologic changes in calf skeletal muscle, including smaller calf muscle area, increased calf muscle fat content, impaired leg strength, and impaired metabolic function. People with severe PAD have poorer peroneal nerve conduction velocity compared with people with mild PAD or no PAD. The degree of ischemia-related pathophysiologic changes in lower extremity muscles and peripheral nerves of people with PAD are associated with the degree of functional impairment. New interventions are needed to improve functional performance and prevent mobility loss in the large number of patients with PAD, including in those who are asymptomatic or who have exertional leg symptoms other than claudication.

Clinical Interest of Ambulatory Assessment of Physical Activity and Walking Capacity in Peripheral Artery Disease

The purpose of the present review was to provide, for the first time, a comprehensive analysis and synthesis of the available studies that highlighted the clinical interest of the ambulatory assessment of either physical activity (PA) or walking capacity in patients with lower extremity peripheral artery disease (PAD). We identified 96 related articles published up to March 2015 through a computer-assisted search of the MEDLINE, EMBASE, and Web of Science databases. Ambulatory-measured PA or related energy expenditure (EE) in PAD patients was performed in 87 of the 96 included studies. The main clinical interests of these measurements were (a) the assessment of PA/EE pattern; (b) the characterization of walking pattern; and (c) the control of training load during home-based walking programs. Ambulatory-measured walking capacity was performed in the remaining studies, using either Global Positioning System receivers or the Peripheral Arterial Disease Holter Control device. Highlighted clinical interests were (a) the assessment of community-based walking capacity; (b) the use of new outcomes to characterize walking capacity, besides the conventional absolute claudication distance; and (c) the association with the patient's self-perception of walking capacity. This review also provides for the clinicians step-by-step recommendations to specifically assess PA or walking capacity in PAD patients.

Supervised vs unsupervised exercise for intermittent claudication: A systematic review and meta-analysis

BACKGROUND

Supervised exercise (SE) is widely accepted as an effective therapy for intermittent claudication (IC), but its use is limited by cost. Unsupervised exercise (UE) represents a less costly alternative. We assessed the comparative effectiveness of SE vs UE in patients with IC.

METHODS AND RESULTS

We searched PubMed, EMBASE, and the Cochrane Database of Systematic Reviews and identified 27 unique studies (24 randomized controlled trials, 4 observational studies) that evaluated the comparative effectiveness of SE vs UE in 2074 patients with IC. Compared with UE, SE was associated with a moderate improvement in maximal walking distance at 6 months (effect size 0.77, 95% CI 0.36-1.17, P < .001) and 12 months (effect size 0.56, 95% CI 0.34-0.77, P < .001). Supervised exercise also improved claudication distance to a moderate extent compared with UE at 6 months (effect size 0.63, 95% CI 0.40-0.85, P < .001) and 12 months (effect size 0.41, 95% CI 0.18-0.65, P = .001). There was no difference in the Short Form-36 quality of life at 6 months (effect size -0.05, 95% CI -0.50 to 0.41, P = .84) or walking impairment questionnaire distance (effect size 0.24, 95% CI -0.03 to 0.50, P = .08) or speed (effect size 0.26, 95% CI -0.06 to 0.59, P = .11).

CONCLUSIONS

In claudication patients, SE is more effective than UE at improving maximal walking and claudication distances, yet there is no difference in general quality of life or patient-reported community-based walking. Further studies are needed to investigate the relationship between functional gain and disease-specific quality of life.

Unsupervised exercise and mobility loss in peripheral artery disease: a randomized controlled trial

Background

Few medical therapies improve lower extremity functioning in people with lower extremity peripheral artery disease (PAD). Among people with PAD, we studied whether a group-mediated cognitive behavioral intervention promoting home-based unsupervised exercise prevented mobility loss and improved functional performance compared to control.

Methods and Results

One hundred ninety-four PAD participants were randomized. During months 1 to 6, the intervention group met weekly with other PAD participants and a facilitator. Group support and self-regulatory skills were used to help participants adhere to walking exercise. Ninety-percent of exercise was conducted at or near home. The control group attended weekly lectures. During months 6 to 12, each group received telephone contact only. Primary outcomes have been reported. Here we compare changes in exploratory outcomes of mobility loss (the inability to climb a flight of stairs or walk one-quarter mile without assistance), walking velocity, and the Short Physical Performance Battery. Compared to controls, fewer participants randomized to the intervention experienced mobility loss at 6-month follow-up: 6.3% versus 26.5%, P=0.002, odds ratio=0.19 (95% CI=0.06 to 0.58) and at 12-month follow-up: 5.2% versus 18.5%, P=0.029, odds ratio=0.24 (95% CI=0.06 to 0.97). The intervention improved fast-paced 4-m walking velocity at 6-month follow-up (P=0.005) and the Short Physical Performance Battery at 12-month follow-up (P=0.027), compared to controls.

Conclusions

In exploratory analyses, a group-mediated cognitive behavioral intervention promoting unsupervised walking exercise prevented mobility loss and improved functioning at 6- and 12-month follow-up in PAD patients.

Clinical Trial Registration

URL: http://clinicaltrials.gov. Unique identifier: NCT00693940.

Pharmacological Treatment and Current Management of Peripheral Artery Disease

Patients with peripheral artery disease (PAD) are at heightened risk of both systemic cardiovascular adverse events, as well as limb-related morbidity. The optimal management of patients with PAD requires a comprehensive treatment strategy incorporating both lifestyle changes, including smoking cessation and exercise, as well as optimal medical therapy. Pharmacological therapies for patients with PAD are targeted both at modifying broad risk factors for major adverse cardiovascular events, as well as reducing limb-related morbidity. Observational data suggest that indicated pharmacological treatments are greatly underutilized in PAD, underscoring the need for improvements in patient identification and care delivery. Ongoing trials of novel therapies in patients with PAD will further inform pharmacological strategies to reduce both systemic cardiovascular risk and limb-related morbidity.

The development and pilot randomised controlled trial of a group education programme for promoting walking in people with intermittent claudication

The aim of this study was to develop and pilot a group education programme for promoting walking in people with intermittent claudication. Patient focus groups (n=24) and literature reviews were conducted to inform the development of the education programme, which involves a three-hour group-based education workshop and follow-up telephone support. A pilot study was subsequently conducted in which 23 new patients (Rutherford category 1-3) were randomly assigned to usual care (control) or usual care plus the education programme. Outcomes were assessed at baseline and six weeks including daily steps (tri-axial accelerometer), walking capacity (six-minute walk test and Gardner treadmill test), and quality of life (Intermittent Claudication Questionnaire [ICQ]). Exit interviews were conducted to assess the acceptability and usefulness of the programme. Compared with controls, the intervention group had superior walking capacity and quality of life at six weeks. Mean differences in six-minute walk distance, treadmill maximum walking distance and ICQ score were 44.9 m (95% confidence interval [CI], 6.9 to 82.9), 173 m (95% CI, 23 to 322), and -10.6 (95% CI, -18.9 to -2.3), respectively. The daily step count did not differ between groups. The exit interviews indicated that participants valued attending the programme, that it gave them a greater understanding of their condition, and that they had been walking more for exercise since attending. The results suggest that the education programme is feasible, acceptable, and potentially useful for improving walking capacity and quality of life. A fully-powered trial exploring clinical and cost effectiveness is needed.

TRIAL REGISTRATION NUMBER

ISRCTN06733130 (http://www.controlled-trials.com).

Drug-coated balloons to improve femoropopliteal artery patency: Rationale and design of the LEVANT 2 trial

BACKGROUND

Atherosclerotic peripheral artery disease (PAD) is common and results in limitations in quality of life and potential progression to limb loss. Options for therapy include medical therapy, supervised exercise, surgical revascularization, and, more recently, endovascular therapies to restore arterial perfusion to the limb. Endovascular revascularization has evolved over the past 2 decades, from percutaneous transluminal angioplasty (PTA) to self-expanding stents, atherectomy, laser angioplasty, and drug-eluting stents. Despite impressive technologic advances, PTA remains the standard of care at many institutions and is the recommended primary treatment modality for femoral-popliteal PAD according to current American College of Cardiology Foundation/American Heart Association guidelines. However, restenosis after PTA is common. Therefore, a significant clinical need remains for a device that is able to achieve more durable patency than PTA but does not require a permanent implant. Drug-coated balloons (DCBs) have the potential to address this need. Several randomized controlled clinical trials of PTA balloons coated with different formulations of paclitaxel have been conducted in Europe (N Engl J Med 2008;358:689-699) (Circulation 2008;118:1358-1365) (Circ Cardiovasc Interv 2012;5:831-840) (JACC Cardiovas Interv 2014;7:10-19) and demonstrated more durable efficacy than PTA with comparable safety. These studies were limited by small sample sizes and powered solely for an angiographic primary end point. The pivotal LEVANT 2 trial was designed in collaboration with the US Food and Drug Administration to demonstrate safety and efficacy in a large population and to obtain US Food and Drug Administration approval.

METHODS

A prospective, multicenter, single-blind trial comparing the Lutonix DCB (Bard Lutonix; New Hope, MN) versus PTA for treatment of femoropopliteal PAD (LEVANT 2) is the first US-based 2:1 randomized controlled trial of 476 patients with femoral-popliteal PAD designed to demonstrate superior efficacy and noninferior safety of a novel paclitaxel DCB compared with PTA. The primary efficacy end point is primary patency at 12 months. The primary safety end point is composite freedom at 12 months from perioperative death, index limb amputation, reintervention, and limb-related mortality. A series of important secondary end points include physical functioning, quality of life, revascularizations, and alternative measures of patency. To minimize bias potential for confounding variables, LEVANT 2 (1) excluded patients stented after predilation before randomization, (2) incorporated very stringent criteria for bailout stenting, (3) did not count bailout stenting as a target lesion revascularization or failure of any end point, (4) required a blinded clinician to perform clinical evaluations at follow-up, and (5) required clinical assessment before review of duplex ultrasound results.

CONCLUSIONS

LEVANT 2 represents the first US-inclusive multicenter, randomized controlled trial to assess the safety and efficacy of a novel DCB compared with PTA as primary therapy for symptomatic PAD on the background of standard medical therapy.

Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study

Objectives:

Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication.

Methods:

Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography.

Results:

After 3 months of exercise, clot strength (maximal amplitude) and time to clot formation (R) did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01) and peak walking time (p < 0.05). Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude), one was a smoker (10%) compared to 9 of 13 non-responders (69%) whose maximal amplitude was unchanged or increased (p = 0.0097).

Conclusion:

In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

Community-based walking exercise for peripheral artery disease: An exploratory pilot study

Supervised walking exercise is an effective treatment to improve walking ability of patients with peripheral artery disease (PAD), but few exercise programs in community settings have been effective. The aim of this study was to determine the efficacy of a community-based walking exercise program with training, monitoring and coaching (TMC) components to improve exercise performance and patient-reported outcomes in PAD patients. This was a randomized, controlled trial including PAD patients (n=25) who previously received peripheral endovascular therapy or presented with stable claudication. Patients randomized to the intervention group received a comprehensive community-based walking exercise program with elements of TMC over 14 weeks. Patients in the control group did not receive treatment beyond standard advice to walk. The primary outcome in the intent-to-treat (ITT) analyses was peak walking time (PWT) on a graded treadmill. Secondary outcomes included claudication onset time (COT) and patient-reported outcomes assessed via the Walking Impairment Questionnaire (WIQ). Intervention group patients (n=10) did not significantly improve PWT when compared with the control group patients (n=10) (mean ± standard error: +2.1 ± 0.7 versus 0.0 ± 0.7 min, p=0.052). Changes in COT and WIQ scores were greater for intervention patients compared with control patients (COT: +1.6 ± 0.8 versus -0.6 ± 0.7 min, p=0.045; WIQ: +18.3 ± 4.2 versus -4.6 ± 4.2%, p=0.001). This pilot using a walking program with TMC and an ITT analysis did not improve the primary outcome in PAD patients. Other walking performance and patient self-reported outcomes were improved following exercise in community settings. Further study is needed to determine whether this intervention improves outcomes in a trial employing a larger sample size.

Exercise training for health-related quality of life in peripheral artery disease: A systematic review and meta-analysis

We sought to quantify whether health-related quality of life (HRQoL) is improved through exercise training in people with peripheral artery disease (PAD) and to clarify which prescriptions were optimal for improving HRQoL when compared to usual care. We conducted a systematic search (PubMed, CINAHL, Cochrane Central Register of Controlled Trials; 1966 – 31 August 2014). We only included randomized controlled trials (RCTs) of exercise training versus usual medical care in persons with PAD that included the Walking Impairment Questionnaire (WIQ) and Short-Form Health Survey component summary scores as outcomes. Of 15 RCTs, 1257 participants were studied: 543 participated in supervised exercise, with only 61 undertaking resistance training and 316 unsupervised exercise. When compared to controls, participants who completed any form of exercise training significantly improved their WIQ speed [mean difference (MD) 9.60 (95% CI 6.98 to 12.23, p<0.00001)]; WIQ distance [MD 7.41 (95% CI 4.49 to 10.33, p<0.00001)] and WIQ stair-climbing [MD 5.07 (95% CI 3.16 to 6.99, p<0.00001)]. Walking also significantly improved the Short-Form Physical Component Summary (SF-PCS) score when compared to controls [MD 1.24 (95% CI 0.48 to 2.01, p=0.001)], but not the Mental Component Summary (SF-MCS) score [MD –0.55 (95% CI –1.27 to 0.18, p=0.14)]. Exercise training improves the SF-PCS dimension, as well as perceived walking distance, speed and stair-climbing as measured by the WIQ, but not the SF-MCS score. Future studies should aim to blind assessors of such subjective measures, and study alternative modes and prescriptions of exercise alternative to walking.

Peripheral artery disease and chronic kidney disease: clinical synergy to improve outcomes

Persons with CKD are at a higher risk of developing peripheral artery disease (PAD) and its adverse health outcomes than individuals in the general population who have normal renal function. Classic atherosclerosis risk factors (eg, age, smoking, diabetes, hypertension, and hyperlipidemia) are common in patients with CKD, but CKD also imposes additional unique risk factors that promote arterial disease (eg, chronic inflammation, hypoalbuminemia, and a procalcific state). Current nephrology clinical practice is adversely affected by PAD diagnostic challenges, the complexities of managing 2 serious comorbid diseases, delayed vascular specialist referral, and slow PAD treatment initiation in patients with CKD. Persons with CKD are less likely to be provided recommended "optimal" PAD care. The knowledge that both limb and mortality outcomes are significantly worse in patients with CKD, especially those on dialysis, is not just a biologic fact but can serve as a care delivery call to action. Nephrologists can facilitate positive change. This article proposes that patients with PAD and CKD be strategically comanaged by care teams that encompass the skills to create and use evidence-based care pathways. This proposed collaborative multidisciplinary approach will include vascular medicine specialists, nephrologists, wound specialists, and mid-level providers. Just as clinical care quality metrics have served as the base for ESRD and acute MI quality improvement, it is time that such quality outcomes metrics be initiated for the large PAD-CKD population. This new system will identify and resolve key gaps in the current care model so that clinical outcomes improve within a cost-effective care frame for this vulnerable population.