Cardiovascular training effect associated with polestriding exercise in patients with peripheral arterial disease

The effects of including quality of life responses in models to predict walking performance of patients with intermittent claudication

OBJECTIVES

To examine the accuracy of previously developed prediction models of treadmill walking performance in patients with intermittent claudication (IC) due to peripheral arterial disease (PAD); and to examine the accuracy of new prediction models.

DESIGN

Analysis of data collected in a previous randomised clinical trial.

MATERIALS

Ninety-three assessments of 28 patients diagnosed with IC due to PAD.

METHODS

Patients undertook routine clinical assessments, quality of life (QOL) questionnaires and treadmill walking tests. Walking performance and estimates based on prediction models were compared via paired t-tests or Wilcoxon Rank Sum tests. Stepwise linear regression generated models to predict walking performance from clinical measures and QOL responses. Accuracy was determined as the absolute error between model estimates and patient results.

RESULTS

Walking performance was significantly underestimated (35-71% error) by previously developed prediction models. Models developed in the current study identified QOL responses as the most significant predictors of current walking performance but these models still resulted in substantial errors (19-84%).

CONCLUSIONS

Previously published predictors of walking performance significantly underestimated patient's ability in practise. Predictions based upon clinical measurements and QOL responses were developed however, their accuracy was also limited. Further research is needed regarding walking performance prediction to assist clinicians with assessment of PAD severity and treatment effectiveness.

The effect of exercise on haemodynamics in intermittent claudication: a systematic review of randomized controlled trials

Changes in lower limb haemodynamics such as arterial pressure and/or flow have often been, and continue to be, cited as possible mechanisms for the improvement in walking performance that occurs with exercise training in individuals with peripheral arterial disease (PAD), but data are conflicting in this regard. There are a small number of literature reviews examining the effects of exercise on PAD, however, there has been insufficient analysis synthesizing possible mechanisms of effect, overall benefits and limitations of these trials. Our objective was therefore to systematically review the evidence for the effect of exercise on lower limb haemodynamic measures of resting and post-exercise ankle brachial index (ABI), resting toe pressure, and resting and reactive hyperaemic calf blood flow in PAD. A systematic search of studies published between 1934 and March 2010 was conducted using MEDLINE, EMBASE, AMED, SportDiscus, CINAHL, PEDro, Premedline, Google Scholar and Web of Knowledge databases. Eligible studies included randomized controlled trials using an exercise intervention for the treatment of intermittent claudication with haemodynamic measures of disease severity as outcomes. Relative effect sizes (ESs) and 95% confidence intervals were calculated for outcomes. Correlation and regression analyses were performed to establish relationships between symptoms and haemodynamic outcomes. Thirty-three trials including 1237 subjects with mild to moderate claudication met the eligibility criteria. Exercise did not significantly change lower extremity haemodynamics in most trials; nor were clinical improvements related to changes in resting ABI (mean ES 0.09 +/- 0.26; r = 0.02; p = 0.94), post-exercise ABI (mean ES 0.18 +/- 0.3; r = -0.33; p = 0.52) or reactive hyperaemic calf blood flow (mean ES 0.38 +/- 0.67; r = 0.35; p = 0.26). A relationship may exist between a change in symptoms and changes in resting toe pressure (mean ES 0.22 +/- 0.22; r = 0.75; p = 0.25) and resting calf blood flow (mean ES 0.09 +/- 0.16; r = 0.59; p = 0.22). Changes in resting and post-exercise ABI and reactive hyperaemic calf blood flow do not appear to explain the clinical benefits of exercise in PAD. More study is required in the areas of resting toe pressure and resting calf blood flow.

Supervised Exercise in Intermittent Claudication: A Sedentary Notion?

The benefit of exercise in the management of intermittent claudication has been explored through extensive research in the preceding decades. Within the clinical setting, there is often little differentiation between home-based and supervised exercise regimens. We examined the history and qualification of supervised exercise as a distinct treatment modality from nonsupervised exercise in intermittent claudication. A Medline, Embase, Ovid, Cochrane Database, and Google Scholar search was performed on all studies published until December 31, 2007, investigating the use of supervised exercise in peripheral arterial disease. Supervised exercise is well grounded in evidence to support its superiority over nonsupervised exercise in the management of intermittent claudication, conveying marked improvement in symptomatology, function, and quality of life. Further research is required to determine the nature of the advantage that supervision affords.

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)).

OBJECTIVES

To determine the effects of exercise programmes on IC, particularly in respect of reduction of symptoms on walking and improvement in quality of life.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (last search February 2008) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2008, Issue 1.

SELECTION CRITERIA

Randomised controlled trials of exercise regimens in people with IC due to peripheral arterial disease.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality.

MAIN RESULTS

Twenty-two trials met the inclusion criteria involving a total of 1200 participants with stable leg pain. Follow-up period was from two weeks to two years. There was some variation in the exercise regimens used, all recommended at least two sessions weekly of mostly supervised exercise. All trials used a treadmill walking test for one of the outcome measures. Quality of the included trials was good, though the majority of trials were small with 20 to 49 participants. Fourteen trials compared exercise with usual care or placebo; patients with various medical conditions or other pre-existing limitations to their exercise capacity were generally excluded.Compared with usual care or placebo, exercise significantly improved maximal walking time: mean difference (MD) 5.12 minutes (95% confidence interval (CI) 4.51 to 5.72;) with an overall improvement in walking ability of approximately 50% to 200%; exercise did not affect the ankle brachial pressure index (ABPI) (MD -0.01, 95% CI -0.05 to 0.04). Walking distances were also significantly improved: pain-free walking distance MD 82.19 metres (95% CI 71.73 to 92.65) and maximum walking distance MD 113.20 metres (95% CI 94.96 to 131.43). Improvements were seen for up to two years. The effect of exercise compared with placebo or usual care was inconclusive on mortality, amputation and peak exercise calf blood flow due to limited data.Evidence was generally limited for exercise compared with surgical intervention, angioplasty, antiplatelet therapy, pentoxifylline, iloprost and pneumatic foot and calf compression due to small numbers of trials and participants. Angioplasty may produce greater improvements than exercise in the short term but this effect may not be sustained.

AUTHORS' CONCLUSIONS

Exercise programmes were of significant benefit compared with placebo or usual care in improving walking time and distance in selected patients with leg pain from IC.

The role of exercise training in peripheral arterial disease

Peripheral arterial disease (PAD) is currently a major health problem affecting 8-12 million Americans, 15-40% of whom will have intermittent claudication that can lead to substantial impairment in their ability to carry out normal daily activities as well as perform the recommended cardiovascular exercise. Supervised exercise training is an effective tool in the treatment of claudication and is currently a recommended first-line therapy for patients with this condition. In addition to improving pain-free walking distance and quality of life, supervised exercise training can improve many cardiovascular risk factors, possibly reducing the risk for subsequent myocardial infarction, stroke, and death. This paper will review the benefits of supervised exercise training in patients with PAD.

Exercícios resistidos terapêuticos para indivíduos com doença arterial obstrutiva periférica: evidências para a prescrição

A prática regular de exercícios é parte do tratamento clínico inicial para pacientes com doença arterial obstrutiva periférica. Nesse sentido, a utilização de exercícios contra resistência (exercícios resistidos) tem sido amplamente recomendada para diferentes populações, especialmente para pessoas idosas com e sem doenças associadas. Os poucos trabalhos encontrados utilizando essa forma de exercícios em pacientes com doença arterial obstrutiva periférica documentam a sua eficiência terapêutica. No entanto, os efeitos documentados dos exercícios resistidos em outras populações têm evidenciado melhoria da aptidão física e da qualidade de vida, com segurança cardiovascular e músculo-esquelética. Essas informações fornecem indicativos sobre os possíveis benefícios dos exercícios resistidos na terapia de indivíduos com doença arterial obstrutiva periférica. Nesse sentido, esta revisão objetivou apresentar informações científicas que permitam auxiliar a prescrição dos exercícios resistidos para essa população.

Peripheral Arterial Disease in Older Adults

Patients with peripheral arterial disease experience significant functional limitations due to ischemic symptoms (claudication) and are at high risk for cardiovascular disease morbidity and mortality resulting from untreated cardiovascular disease risk factors and aggressive atherosclerosis. Peripheral arterial disease is commonly undiagnosed and cardiovascular disease risk factors are frequently untreated in this population. The increased risk associated with peripheral arterial disease necessitates greater emphasis on detection and management, not only to improve survival but to improve functional capacity and quality of life. This article briefly describes the detection and medical management with emphasis on lifestyle modification for elders with peripheral arterial disease.