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

Step-monitored home exercise improves ambulation, vascular function, and inflammation in symptomatic patients with peripheral artery disease: a randomized controlled trial

Background

This prospective, randomized, controlled clinical trial compared changes in primary outcome measures of claudication onset time (COT) and peak walking time (PWT), and secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle hemoglobin oxygen saturation (StO₂) in patients with symptomatic peripheral artery disease (PAD) following new exercise training using a step watch (NEXT Step) home‐exercise program, a supervised exercise program, and an attention‐control group.

Methods and Results

One hundred eighty patients were randomized. The NEXT Step program and the supervised exercise program consisted of intermittent walking to mild‐to‐moderate claudication pain for 12 weeks, whereas the controls performed light resistance training. Change scores for COT (P<0.001), PWT (P<0.001), 6‐minute walk distance (P=0.028), daily average cadence (P=0.011), time to minimum calf muscle StO₂ during exercise (P=0.025), large‐artery elasticity index (LAEI) (P=0.012), and high‐sensitivity C‐reactive protein (hsCRP) (P=0.041) were significantly different among the 3 groups. Both the NEXT Step home program and the supervised exercise program demonstrated a significant increase from baseline in COT, PWT, 6‐minute walk distance, daily average cadence, and time to minimum calf StO₂. Only the NEXT Step home group had improvements from baseline in LAEI, and hsCRP (P<0.05).

Conclusions

NEXT Step home exercise utilizing minimal staff supervision has low attrition, high adherence, and is efficacious in improving COT and PWT, as well as secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle StO₂ in symptomatic patients with PAD.

Clinical Trial Registration

URL: ClinicalTrials.gov. Unique Identifier: NCT00618670.

Safety and effectiveness of endovascular therapy for claudication in octogenarians

BACKGROUND

Advanced age (≥ 80 years) has been associated with adverse outcomes after lower extremity bypass for critical limb ischemia (CLI), but endovascular therapy (ET) is reported to have comparable safety across age groups. Here, we assess the safety and effectiveness of advanced age on outcomes after ET for lifestyle-limiting intermittent claudication (IC).

METHODS

A retrospective review of a prospectively maintained institutional database (2007-2012) identified all patients undergoing ET for IC. Demographics, procedural details, and outcomes were assessed via univariate analysis and multivariate Cox regression. Effectiveness was assessed across a panel of outcome metrics including the following: overall survival, freedom from major adverse limb event (MALE), and freedom from reintervention, amputation, or restenosis (RAS). Freedom from MALE + perioperative death (MALE + POD) was the primary safety end point.

RESULTS

Two hundred thirty-six patients underwent primary ET for 284 affected limbs. Of these, 46 interventions (16%) were performed in patients ≥ 80 years old. The average age of octogenarians treated was 84.4 years compared with 67.4 years among those aged <80 (P < 0.001). Compared with younger claudicants, octogenarians were less likely to have hypercholesterolemia (43.5% vs. 63.9%, P = 0.01) and more likely to deny a history of smoking (41.3% vs. 14.7%, P < 0.001). Octogenarians were also more likely to undergo interventions involving the popliteal artery (50% vs. 31.9%, P = 0.03). There were no other significant differences in demographics, comorbidities, TransAtlantic Inter-Society Consensus II classification, or treated arterial segment. Thirty-day freedom from MALE + POD was 100% in octogenarians and 99.6% in patients <80 years, with no difference between age groups. There were no differences in freedom from MALE, freedom from RAS, or overall survival at 1- and 3-year follow-up.

CONCLUSIONS

Although age >80 years has been identified as an independent risk factor for poor outcomes in the surgical treatment of CLI, our results suggest that ET for selected octogenarians with lifestyle-limiting claudication is as safe and effective as ET in younger patients. Advanced age alone should not prohibit consideration of ET for patients with IC.

Association of lower extremity performance with cardiovascular and all-cause mortality in patients with peripheral artery disease: a systematic review and meta-analysis

Background

Peripheral artery disease (PAD) is associated with impaired mobility and a high rate of mortality. The aim of this systematic review was to investigate whether reduced lower extremity performance was associated with an increased incidence of cardiovascular and all‐cause mortality in people with PAD.

Methods and Results

A systematic search of the MEDLINE, EMBASE, SCOPUS, Web of Science, and Cochrane Library databases was conducted. Studies assessing the association between measures of lower extremity performance and cardiovascular or all‐cause mortality in PAD patients were included. A meta‐analysis was conducted combining data from commonly assessed performance tests. The 10 identified studies assessed lower extremity performance by strength tests, treadmill walking performance, 6‐minute walk, walking velocity, and walking impairment questionnaire (WIQ). A meta‐analysis revealed that shorter maximum walking distance was associated with increased 5‐year cardiovascular (unadjusted RR=2.54, 95% CI 1.86 to 3.47, P<10⁻⁵, n=1577, fixed effects) and all‐cause mortality (unadjusted RR=2.23 95% CI 1.85 to 2.69, P<10⁻⁵, n=1710, fixed effects). Slower 4‐metre walking velocity, a lower WIQ stair‐climbing score, and poor hip extension, knee flexion, and plantar flexion strength were also associated with increased mortality. No significant associations were found for hip flexion strength, WIQ distance score, or WIQ speed score with mortality.

Conclusions

A number of lower extremity performance measures are prognostic markers for mortality in PAD and may be useful clinical tools for identifying patients at higher risk of death. Further studies are needed to determine whether interventions that improve measures of lower extremity performance reduce mortality.

Effectiveness of a new exercise program after lower limb arterial blood flow surgery in patients with peripheral arterial disease: a randomized clinical trial

OBJECTIVE

The aim of this study was to evaluate the effectiveness of a supervised exercise program (SEP) plus at home nonsupervised exercise therapy (non-SET) on functional status, quality of life (QoL) and hemodynamic response in post-lower-limb bypass surgery patients.

RESULTS

One hundred and seventeen patients were randomized to an intervention (n = 57) or a control group (n = 60). A new individual SEP was designed for patients with peripheral arterial disease (PAD) and applied to the studied subjects of the intervention group who also continued non-SET at home, whereas those assigned to the control group received just usual SEP according to a common cardiovascular program. The participants of the study were assessed by a 6-min walking test (6 MWT), an ankle-brachial index (ABI), and the Medical Outcomes Study Short Form-36 (SF-36) of QoL at baseline, at 1 and 6 months after surgery. A significant improvement was observed in the walked distance in the intervention group after 6 months compared with the control group (p < 0.001). The intervention group had significantly higher QoL score in the physical and mental component of SF-36 (p < 0.05).

CONCLUSIONS

A 6-month application of the new SEP and non-SET at home has yielded significantly better results in walking distance and QoL in the intervention group than in the controls.

Exercise for intermittent claudication

BACKGROUND

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

OBJECTIVES

The prime objective of this review was to determine whether an exercise programme in people with intermittent claudication was effective in alleviating symptoms and increasing walking treadmill distances and walking times. 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 Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched September 2013) and CENTRAL (2013, Issue 8).

SELECTION CRITERIA

Randomised controlled trials of an exercise regimen versus control or versus medical therapy in people with IC due to peripheral arterial disease. Any exercise programme or regimen used in the treatment of intermittent claudication was included, such as walking, skipping and running. Inclusion of trials was not affected by the 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 maximal walking distance), ankle brachial index (ABI), quality of life, morbidity or amputation; if none of these were reported the trial was not included in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

Eleven additional studies were included in this update making a total of 30 trials which met the inclusion criteria, involving a total of 1816 participants with stable leg pain. The follow-up period ranged from two weeks to two years. The types of exercise varied from strength training to polestriding and upper or lower limb exercises; generally supervised sessions were at least twice a week. Most trials used a treadmill walking test for one of the outcome measures. Quality of the included trials was moderate, mainly due to an absence of relevant information. The majority of trials were small with 20 to 49 participants. Twenty trials compared exercise with usual care or placebo, the remainder of the trials compared exercise to medication (pentoxifylline, iloprost, antiplatelet agents and vitamin E) or pneumatic calf compression; people with various medical conditions or other pre-existing limitations to their exercise capacity were generally excluded.Overall, when taking the first time point reported in each of the studies, exercise significantly improved maximal walking time when compared with usual care or placebo: mean difference (MD) 4.51 minutes (95% confidence interval (CI) 3.11 to 5.92) with an overall improvement in walking ability of approximately 50% to 200%. Walking distances were also significantly improved: pain-free walking distance MD 82.29 metres (95% CI 71.86 to 92.72) and maximum walking distance MD 108.99 metres (95% CI 38.20 to 179.78). Improvements were seen for up to two years, and subgroup analyses were performed at three, six and 12 months where possible. Exercise did not improve the ABI (MD 0.05, 95% CI 0.00 to 0.09). The effect of exercise, when compared with placebo or usual care, was inconclusive on mortality, amputation and peak exercise calf blood flow due to limited data. No data were given on non-fatal cardiovascular events.Quality of life measured using the Short Form (SF)-36 was reported at three and six months. At three months, physical function, vitality and role physical all significantly improved with exercise, however this was a limited finding as this measure was only reported in two trials. At six months five trials reported outcomes of a significantly improved physical summary score and mental summary score secondary to exercise. Only two trials reported improvements in other domains, physical function and general health.Evidence was generally limited for exercise compared with antiplatelet therapy, pentoxifylline, iloprost, vitamin E and pneumatic foot and calf compression due to small numbers of trials and participants.

AUTHORS' CONCLUSIONS

Exercise programmes are of significant benefit compared with placebo or usual care in improving walking time and distance in people with leg pain from IC who were considered to be fit for exercise intervention.

Role of the latest endovascular technology in the treatment of intermittent claudication

Intermittent claudication is a serious symptom in patients with peripheral arterial disease, and severely limits activities of daily living. Conservative treatment (optimal medical therapy and exercise rehabilitation programs) and revascularization procedures (endovascular treatment [EVT] or open bypass surgery) can relieve intermittent claudication. Among these treatment options, EVT has developed dramatically during the past decade, and has enabled physicians to offer less invasive treatment options with increasing durability. EVT for aortoiliac lesions has matured, and its long-term patency now approaches that of open bypass surgery. The latest EVT technologies include drug-eluting stents, stent grafts, drug-coated balloons, and bioresorbable stents. The recently reported patency of stent grafts in the femoropopliteal lesions was comparable with that of the prosthetic bypass graft. In the course of the paradigm shift from bypass surgery to EVT, evidence of any long-term benefit of EVT compared with supervised exercise is still inconclusive. EVT could improve walking performance in the short-term, while supervised exercise could improve walking performance more efficiently in the long-term. Combined treatment with EVT and exercise may offer the most sustainable and effective symptom relief. This paper reviews the relevant literature on the treatment of intermittent claudication, focusing on the latest EVT technologies, and outlines a strategy for achieving long-term benefits.

Home-based walking exercise in peripheral artery disease: 12-month follow-up of the GOALS randomized trial

Background

We studied whether a 6‐month group‐mediated cognitive behavioral (GMCB) intervention for peripheral artery disease (PAD) participants, which promoted home‐based walking exercise, improved 6‐minute walk and other outcomes at 12‐month follow‐up, 6 months after completing the intervention, compared to a control group.

Methods and Results

We randomized PAD participants to a GMCB intervention or a control group. During phase I (months 1 to 6), the intervention used group support and self‐regulatory skills during weekly on‐site meetings to help participants adhere to home‐based exercise. The control group received weekly on‐site lectures on topics unrelated to exercise. Primary outcomes were measured at the end of phase I. During phase II (months 7 to 12), each group received telephone contact. Compared to controls, participants randomized to the intervention increased their 6‐minute walk distance from baseline to 12‐month follow‐up, (from 355.4 to 381.9 m in the intervention versus 353.1 to 345.6 m in the control group; mean difference=+34.1 m; 95% confidence interval [CI]=+14.6, +53.5; P<0.001) and their Walking Impairment Questionnaire (WIQ) speed score (from 36.1 to 46.5 in the intervention group versus 34.9 to 36.5 in the control group; mean difference =+8.8; 95% CI=+1.6, +16.1; P=0.018). Change in the WIQ distance score was not different between the 2 groups at 12‐month follow‐up (P=0.139).

Conclusions

A weekly on‐site GMCB intervention that promoted home‐based walking exercise intervention for people with PAD demonstrated continued benefit at 12‐month follow‐up, 6 months after the GMCB intervention was completed.

Clinical Trial Registration

URL: ClinicalTrials.gov. Unique identifier: NCT00693940.

Leg discomfort: beyond the joints

Although simple characterization of discomfort as cramps, heaviness, shooting pains, and so forth can be misleading, history and examination are key to accurate diagnosis. Absence of both dorsalis pedis and posterior tibial pulses strongly suggests peripheral arterial disease (PAD), and the presence of either pulse makes PAD less likely. Hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) are a common cause of lower extremity myalgias. Restless legs syndrome causes nocturnal discomfort but must be distinguished from confounding“mimics." Neurologic causes of leg symptoms include lumbar spinal stenosis, radiculopathy, distal symmetric polyneuropathy, and entrapment neuropathy. Many common causes of leg discomfort can be managed conservatively.

On the associations between physical activity and quality of life: findings from an Australian nationally representative panel survey

PURPOSE

The purpose of this study is to provide a comprehensive analysis of the associations between the frequency of moderate or vigorous physical activity (MVPA) and quality of life (QoL) measures using longitudinal data and panel regression models on a large, representative sample of the Australian population.

METHODS

This study used yearly panel data on over 23,000 individuals collected by the Household, Income and Labour Dynamics in Australia Survey between 2001 and 2011. Ordinary least squares and fixed effects regression models were used to examine the associations between the weekly frequency of MVPA and several indicators of QoL, including both measures of health-related QoL (such as those derivable from the SF-36) and global subjective well-being assessments (such as self-reported life satisfaction), controlling for observable and unobservable factors.

RESULTS

Our results provided consistent evidence that the frequency of MVPA is related to QoL and proved to be robust. A higher frequency of MVPA was related to higher scores in each of the outcomes analysed and using either of two different estimation strategies. The most pronounced associations emerged between the frequency of MVPA and the physical and vitality dimensions of the SF-36. A change from undertaking no MVPA at all to undertaking such activity once a week was remarkably associated with higher QoL. The influence of MVPA on global life satisfaction was only partially channelled through physical and mental health.

CONCLUSION

We provide strong evidence that MVPA is related to QoL, thus adding to the large body of scientific literature demonstrating the benefits of becoming physically active.

A group-mediated, home-based physical activity intervention for patients with peripheral artery disease: effects on social and psychological function

BACKGROUND

PAD is a disabling, chronic condition of the lower extremities that affects approximately 8 million people in the United States. The purpose of this study was to determine whether an innovative home-based walking exercise program for patients with peripheral artery disease (PAD) improves self-efficacy for walking, desire for physical competence, satisfaction for physical functioning, social functioning, and acceptance of PAD related pain and discomfort.

METHODS

The design was a 6-month randomized controlled clinical trial of 194 patients with PAD. Participants were randomized to 1 of 2 parallel groups: a home-based group-mediated cognitive behavioral walking intervention or an attention control condition.

RESULTS

Of the 194 participants randomized, 178 completed the baseline and 6-month follow-up visit. The mean age was 70.66 (±9.44) and was equally represented by men and women. Close to half of the cohort was African American. Following 6-months of treatment, the intervention group experienced greater improvement on self-efficacy (p = .0008), satisfaction with functioning (p = .0003), pain acceptance (p = .0002), and social functioning (p = .0008) than the control group; the effects were consistent across a number of potential moderating variables. Change in these outcomes was essentially independent of change in 6-minute walk performance.

TRIAL REGISTRATION

[ClinicalTrials.gov Identifier: NCT00693940].

Validation of the English version of the Walking Estimated-Limitation Calculated by History (WELCH) questionnaire in patients with intermittent claudication

The Walking Estimated-Limitation Calculated by History (WELCH) questionnaire has recently been proposed as a valid and simple instrument for assessing walking limitation in patients with intermittent claudication. The aim of this study was to validate an English version of the WELCH questionnaire in an English native population. Thirty-nine patients (ankle–brachial index 0.59 ± 0.16, age 65 ± 11 years, 82% male) completed an English version of the WELCH questionnaire. Maximum walking distance was measured objectively using the Gardner–Skinner treadmill test and the 6-minute walk test. The median WELCH score was 24 (9–39). Maximum walking distances were 412 m (149–675 m) for the treadmill test and 381 ± 88 m for the 6-minute walking test. The Spearman’s correlation coefficient was ρ = 0.59 between the WELCH score and treadmill distance ( p < 0.001) and ρ = 0.82 between the WELCH score and 6-minute walk distance ( p < 0.001). These findings suggest that the English version of the WELCH questionnaire is a valid instrument for assessing walking impairment in patients with intermittent claudication.

Effect of progenitor cell mobilization with granulocyte-macrophage colony-stimulating factor in patients with peripheral artery disease: a randomized clinical trial

IMPORTANCE

Many patients with peripheral artery disease (PAD) have walking impairment despite therapy. Experimental studies in animals demonstrate improved perfusion in ischemic hind limb after mobilization of bone marrow progenitor cells (PCs), but whether this is effective in patients with PAD is unknown.

OBJECTIVE

To investigate whether therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) improves exercise capacity in patients with intermittent claudication.

DESIGN, SETTING, AND PARTICIPANTS

In a phase 2 double-blind, placebo-controlled study, 159 patients (median [SD] age, 64 [8] years; 87% male, 37% with diabetes) with intermittent claudication were enrolled at medical centers affiliated with Emory University in Atlanta, Georgia, between January 2010 and July 2012.

INTERVENTIONS

Participants were randomized (1:1) to received 4 weeks of subcutaneous injections of GM-CSF (leukine), 500 μg/day 3 times a week, or placebo. Both groups were encouraged to walk to claudication daily.

MAIN OUTCOMES AND MEASURES

The primary outcome was peak treadmill walking time (PWT) at 3 months. Secondary outcomes were PWT at 6 months and changes in circulating PC levels, ankle brachial index (ABI), and walking impairment questionnaire (WIQ) and 36-item Short-Form Health Survey (SF-36) scores.

RESULTS

Of the 159 patients randomized, 80 were assigned to the GM-CSF group. The mean (SD) PWT at 3 months increased in the GM-CSF group from 296 (151) seconds to 405 (248) seconds (mean change, 109 seconds [95% CI, 67 to 151]) and in the placebo group from 308 (161) seconds to 376 (182) seconds (change of 56 seconds [95% CI, 14 to 98]), but this difference was not significant (mean difference in change in PWT, 53 seconds [95% CI, -6 to 112], P = .08). At 3 months, compared with placebo, GM-CSF improved the physical functioning subscore of the SF-36 questionnaire by 11.4 (95% CI, 6.7 to 16.1) vs 4.8 (95% CI, -0.1 to 9.6), with a mean difference in change for GM-CSF vs placebo of 7.5 (95% CI, 1.0 to 14.0; P = .03). Similarly, the distance score of the WIQ improved by 12.5 (95% CI, 6.4 to 18.7) vs 4.8 (95% CI, -0.2 to 9.8) with GM-CSF compared with placebo (mean difference in change, 7.9 [95% CI, 0.2 to 15.7], P = .047). There were no significant differences in the ABI, WIQ distance and speed scores, claudication onset time, or mental or physical component scores of the SF-36 between the groups.

CONCLUSIONS AND RELEVANCE

Therapy with GM-CSF 3 times a week did not improve treadmill walking performance at the 3-month follow-up. The improvements in some secondary outcomes with GM-CSF suggest that it may warrant further study in patients with claudication.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01041417.

The Effect of Lipid Modification on Peripheral Artery Disease after Endovascular Intervention Trial (ELIMIT)

METHODS

A total of 102 patients were randomized to either mono-therapy with simvastatin (40 mg daily) or triple-therapy with simvastatin (40 mg daily), extended-release niacin (1500 mg daily), and ezetimibe (10 mg daily). MRI was performed at baseline and 6, 12, and 24 months. SFA wall, lumen, and total vessel volumes were quantified. MRI-derived SFA parameters and lipids were analyzed with multilevel models and nonparametric tests, respectively.

RESULTS

Baseline characteristics did not differ between mono and triple-therapy groups, except for ethnicity (p = 0.02). SFA wall, lumen, and total vessel volumes increased non-significantly for both groups between baseline and 24-months. Non-high-density lipoprotein cholesterol was significantly reduced at 12 months with triple-therapy compared with mono-therapy (p = 0.01).

CONCLUSION

No significant differences were observed between mono-therapy using simvastatin and triple-therapy with simvastatin, extended-release niacin, and ezetimibe for 24-month changes in SFA wall, lumen, and total vessel volumes.

CLINICAL TRIAL REGISTRATION INFORMATION

NCT00687076; Link: http://clinicaltrials.gov/ct2/show/NCT00687076.

Community walking programs for treatment of peripheral artery disease

BACKGROUND

Supervised walking programs offered at medical facilities for patients with peripheral artery disease (PAD) and intermittent claudication (IC), although effective, are often not used due to barriers, including lack of reimbursement and the need to travel to specialized locations for the training intervention. Walking programs for PAD patients that occur in community settings, such as those outside of supervised settings, may be a viable treatment option because they are convenient and potentially bypass the need for supervised walking. This review evaluated the various methods and outcomes of community walking programs for PAD.

METHODS

A literature review using appropriate search terms was conducted within PubMed/MEDLINE and the Cochrane databases to identify studies in the English language that used community walking programs to treat PAD patients with IC. Search results were reviewed, and relevant articles were identified that form the basis of this review. The primary outcome was peak walking performance on the treadmill.

RESULTS

Ten randomized controlled trials examining peak walking outcomes in 558 PAD patients demonstrated that supervised exercise programs were more effective than community walking studies that consisted of general recommendations for patients with IC to walk at home. Recent community trials that incorporated more advice and feedback for PAD patients in general resulted in similar outcomes, with no differences in peak walking time compared with supervised walking exercise groups.

CONCLUSIONS

Unstructured recommendations for patients with symptomatic PAD to exercise in the community are not efficacious. Community walking programs with more feedback and monitoring offer improvements in walking performance for patients with claudication and may bypass some obstacles associated with facility-based exercise programs.

Progenitor cell release plus exercise to improve functional performance in peripheral artery disease: the PROPEL Study

Functional impairment, functional decline, and mobility loss are major public health problems in people with lower extremity peripheral artery disease (PAD). Few medical therapies significantly improve walking performance in PAD. We describe methods for the PROgenitor cell release Plus Exercise to improve functionaL performance in PAD (PROPEL) Study, a randomized controlled clinical trial designed to determine whether granulocyte-macrophage colony stimulating factor (GM-CSF) combined with supervised treadmill walking exercise improves six-minute walk distance more than GM-CSF alone, more than supervised treadmill exercise alone, and more than placebo plus attention control in participants with PAD, respectively. PROPEL Study participants are randomized to one of four arms in a 2 by 2 factorial design. The four study arms are GM-CSF plus supervised treadmill exercise, GM-CSF plus attention control, placebo plus supervised exercise therapy, or placebo plus attention control. The primary outcome is change in six-minute walk distance at 12-week follow-up. Secondary outcomes include change in brachial artery flow-mediated dilation (FMD), change in maximal treadmill walking time, and change in circulating CD34+ cells at 12-week follow-up. Outcomes are also measured at six-week and six-month follow-up. Results of the PROPEL Study will have important implications for understanding mechanisms of improving walking performance and preventing mobility loss in the large and growing number of men and women with PAD.