Relative Tolerance to Upper- and Lower-Limb Aerobic Exercise in Patients with Peripheral Arterial Disease

Effect of Arm-Ergometry Versus Treadmill Supervised Exercise on Cardiorespiratory Fitness and Walking Distances in Patients With Peripheral Artery Disease: The ARMEX Randomized Clinical Trial

PURPOSE

To compare arm-ergometry and treadmill supervised exercise training on cardiorespiratory fitness and walking distances in patients with peripheral artery disease (PAD).

METHODS

ARMEX was a single-center, single-blinded, parallel group, non-inferiority trial enrolling symptomatic patients with PAD. Patients were randomized (1:1 ratio) to a 12-wk arm-ergometry (AEx) or standard treadmill (TEx) supervised exercise training protocol. The powered primary end point was the change in peak oxygen uptake (VO 2 ) at 12 wk, measured on a treadmill cardiopulmonary exercise test (CPX). Secondary outcomes included changes in VO 2 at the first ventilatory threshold (VT-1), ventilatory efficiency (ratio of minute ventilation [VE] to carbon dioxide production [VCO 2 ], VE/VCO 2 ), walking distances by CPX and 6-min walking test (6MWT), and self-reported walking limitations.

RESULTS

Fifty-six patients (66 ± 8 yr; 88% male) were randomized (AEx, n = 28; TEx, n = 28). At 12 wk, VO 2peak change was not significantly different between groups (0.75 mL/kg/min; 95% CI, -0.94 to 2.44; P = .378), despite a significant increase only in AEx. VO 2 at VT-1 improved in both groups without between-group differences, and VE/VCO 2 slope improved more in AEx. The TEx attained greater improvements in walking distance by CPX (121.08 m; 95% CI, 24.49-217.66; P = .015) and 6MWT (25.08 m; 95% CI, 5.87-44.29; P = .012) and self-perceived walking distance.

CONCLUSIONS

Arm-ergometry was noninferior to standard treadmill training for VO 2peak , and treadmill training was associated with greater improvements in walking distance. Our data support the use of treadmill as a first-line choice in patients with PAD to enhance walking capacity, but arm-ergometry could be an option in selected patients.

The effect of age and sex on peak oxygen uptake during upper and lower body exercise: A systematic review

BACKGROUND

Large scale population norms for peak oxygen uptake (VO2peak) during cycle ergometry (CE) have been published for men and women across a wide range of ages. Although upper body functional capacity has an important role in activities of daily living far less is known regarding the effect of age and sex on upper body functional capacity (i.e. arm crank ergometry; ACE). The aim of this review was to determine the effect of age and sex on VO2peak obtained during ACE and CE in the same participants.

METHOD

The review was pre-registered with PROSEPERO (Ref: CRD42022349566). A database search using Academic Search Complete including CINAHL complete, CINHAL Ultimate, Medline, PubMed, SPORTDiscus was undertaken.

RESULTS

The initial search yielded 460 articles which was reduced to 243 articles following removal of duplicates. Twenty-five articles were subsequently excluded based on title resulting in 218 articles considered for retrieval. Following review of the abstracts, 78 further articles were excluded leaving 140 to be assessed for eligibility. Eighty-five articles were subsequently excluded, resulting in 55 articles being included. The decrease in VO2peak with age during CE was consistent with previous studies. Decreases in VO2peak during ACE with age, although paralleling those of CE, appeared to be of greater functional importance. When changes in VO2peak were considered below the age of 50 years little change was observed for absolute VO2peak during ACE and CE. In contrast, relative VO2peak demonstrated decreases in VO2peak for both ACE and CE likely reflecting increases in body mass and body fat percentage with age. After 50 years of age absolute and relative VO2peak demonstrated more similar and subtle responses. Heterogeneity across studies for both absolute and relative VO2peak between ACE and CE was large. Although strict inclusion criteria were applied, the inter-individual variation in sample populations was likely the main source of heterogeneity. There was a considerable lack data sets available for ages above 40 years of age.

CONCLUSIONS

These responses suggest that upper body VO2peak decreases in line with that of the lower body but, due to the lower peak values achieved during ACE, decreases in VO2peak may have more profound functional impact compared to that for the lower body. Using absolute and relative measures of VO2peak results in different age-related profiles when considered below 50 years of age. To further our understanding of whole body ageing more data is required for participants in mid and later life. The association between VO2peak and underlying physiological factors with age needs to be studied further, particularly in conjunction with activities of daily living and independent living.

Oxygen Uptake Kinetics during Exercise Reveal Central and Peripheral Limitation in Patients with Ilio-Femoral Venous Obstruction

OBJECTIVE

Pulmonary oxygen uptake (V̇O₂) kinetics measured during initiation of exercise mirror energetic transition during daily activity. The aim of this study was to elucidate the pathophysiological mechanisms of exercise limitation of patients with chronic ilio-femoral vein obstruction after deep vein thrombosis by measuring V̇O₂ kinetics compared to patients with peripheral arterial disease (PAD) and healthy individuals.

METHODS

Eleven patients with ilio-femoral vein obstruction (7 man, age 20-65 yrs.), seven patients with PAD (all men, age 44-60 yrs.) and eight healthy participants (5 men, age 28-58 yrs.) were studied. Participants performed upper and lower-limb symptom-limited cardiopulmonary exercise tests on cycle ergometers; and four repeat lower-limb tests at a constant work-rate (WR) corresponding to 90% of the gas exchange threshold for determining V̇O₂ kinetics.

RESULTS

Phase I V̇O₂ amplitude in the constant WR tests (% increase over resting V̇O₂), representing the initial surge in cardiac output caused by the emptying of leg veins, was 59±19% in the ilio-femoral vein obstruction group, 73±22% in peripheral arterial disease and 85±26% in healthy participants (p=0.055 for ilio-femoral vein obstruction vs. healthy). Phase II V̇O₂ kinetics, which largely reflect the kinetics of O₂ consumption in the exercising muscles, were slower in ilio-femoral vein obstruction (tau = 42±6 s), and PAD (tau = 49±19 s), compared to healthy participants (23±4 s; p<0.01) CONCLUSIONS: Slow phase II V̇O₂ kinetics reflect a slow onset of muscular aerobic metabolism in both ilio-femoral vein obstruction and PAD. Low amplitude phase I of V̇O₂ kinetics observed in ilio-femoral vein obstruction suggests a damped cardio-dynamic phase, consistent with reduced venous return from the obstructed veins. These abnormalities of V̇O₂ kinetics may contribute to exercise intolerance in ilio-femoral vein obstruction and PAD.

Experience Implementing Supervised Exercise Therapy for Peripheral Artery Disease

Background

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

Methods

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

Results

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

Conclusions

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

Brief Abstract

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

Clinical predictors of ventilatory threshold achievement in patients with claudication

PURPOSE

Ventilatory threshold (VT) is considered a clinically important marker of cardiovascular function in several populations, including patients with claudication, because it is related to walking capacity and hemodynamics. The purpose of this study was to identify clinical predictors for VT achievement in patients with intermittent claudication.

METHODS

One hundred and seventy-seven (n = 177) patients with intermittent claudication performed a progressive graded cardiopulmonary treadmill test until maximal claudication pain. Oxygen uptake (V˙O2) was continuously measured during the test, and afterwards, VT was visually detected. Clinical characteristics, demographic data, comorbid conditions, and cardiovascular risk factors were obtained. Patients who achieved and did not achieve VT were compared, as well as the workload that VT occurred in the former group.

RESULTS

VT was achieved in 134 patients (76%), and the mean V˙O2 at VT for these patients was 10.8 ± 2.4 mL·kg(-1)·min(-1). Patients who did not achieve VT presented lower ankle brachial index (ABI), claudication onset time, peak walking time, and V˙O2peak, and the proportion of women was higher compared with patients who achieved VT (P < 0.05). Multiple linear regression analysis identified that sex (b = 0.25, P = 0.002), body mass index (b = -0.18, P = 0.025), peak walking time (b = 0.17, P = 0.044), and ABI (b = 0.23, P = 0.006) were predictors of V˙O2 at VT.

CONCLUSIONS

Forty-three patients (24%) with intermittent claudication did not achieve VT, and these patients were mostly women and those with greater severity of disease. Moreover, in those who reached VT, the predictors of poor VT were female sex, high body mass index, low peak walking time, and low ABI.

Combined lentiviral and RNAi technologies for the delivery and permanent silencing of the hsp25 gene

Elevated heat shock protein 27 (Hsp27) expression has been found in a number of tumors, including breast, prostate, gastric, uterine, ovarian, head and neck, and tumor arising from the nervous system and urinary system, and determined to be a predictor of poor clinical outcome. Although the mechanism of action of Hsp27 has been well documented, there are currently no available inhibitors of Hsp27 in clinical trials. RNA interference (RNAi) has the potential to offer more specificity and flexibility than traditional drugs to silence gene expression. Not surprisingly, RNAi has become a major focus for biotechnology and pharmaceutical companies, which are now in the early stages of developing RNAi therapeutics, mostly based on short interfering RNA (siRNAs), to target viral infection, cancer, hypercholesterolemia, cardiovascular disease, macular degeneration, and neurodegenerative diseases. However, the critical issues associated with RNAi as a therapeutic are delivery, specificity, and stability of the RNAi reagents. To date, the delivery is currently considered the biggest hurdle, as the introduction of siRNAs systemically into body fluids can result in their degradation, off-target effects, and immune detection. In this chapter, we discuss a method of combined lentiviral and RNAi-based technology for the delivery and permanent silencing of the hsp25 gene.

Comparison of the effect of upper body-ergometry aerobic training vs treadmill training on central cardiorespiratory improvement and walking distance in patients with claudication

BACKGROUND

Supervised treadmill-walking exercise programs have been proven to be a highly effective in improving walking distance in peripheral arterial disease (PAD) patients with lifestyle-limiting claudication. Limited information is available on the contributions of central cardiorespiratory functions for improving these patients' walking capacity with exercise training.

METHODS

This study randomized 28 participants (21 men; age, 65.6 years; 92.7% smoking history, 36.6% with diabetes) with lifestyle-limiting PAD-related claudication to 3 hours/week of supervised exercise training for 12 weeks, using arm-ergometry (n = 10) or treadmill-walking (n = 10) vs a usual-care control group (n = 8). Cardiorespiratory function measurements were assessed before and after training at a submaximal workload and at the onset of claudication (pain-free walking distance [PFWD]) and at maximal walking distance [(MWD]). Changes in these functions from baseline were analyzed among the groups with analysis of covariance. Associations between variables were determined by Pearson's partial correlations.

RESULTS

The mean baseline demographic, medical, and exercise variables were similar among the groups. There were similar significant differences in the submaximal double product (heart rate × systolic blood pressure) and at MWD, ventilatory threshold, ventilatory oxygen uptake (VO(2)) at onset of claudication, and VO(2) peak in response to training in both exercise groups vs the control group. Statistically significant, moderate correlations (r = 0.60-0.68) were found between changes in all cardiorespiratory variables and changes in PFWD or MWD.

CONCLUSION

Improvements in cardiorespiratory function after arm-ergometry or treadmill-training were significantly associated with improvements in both PFWD and MWD, providing supporting evidence of systemic contributions to exercise training-related improvements in walking capacity seen in patients with claudication.

Comprehensive evaluation and medical management of infrainguinal peripheral artery disease: "when to treat, when not to treat"

Peripheral artery disease (PAD) is a highly prevalent atherosclerotic syndrome associated with significant morbidity and mortality. PAD is defined by atherosclerotic obstruction of the arteries to the legs that reduce arterial flow during exercise or at rest, and is associated with systemic atherosclerosis. The clinical presentation of PAD is quite varied, including patients with atypical leg symptoms, classic intermittent claudication, and critical limb ischemia. Clinical assessment of these patients includes a comprehensive history, physical examination, and noninvasive and invasive vascular studies. The major risk factors for PAD include diabetes mellitus, tobacco abuse, hyperlipidemia, hypertension, and advanced age. Because of the presence of these risk factors, the systemic nature of atherosclerosis, and the high risk of ischemic events, patients with PAD should be candidates for comprehensive secondary prevention strategies, including aggressive glycemic control, all attempts at tobacco cessation, lipid lowering and antihypertensive treatment, antiplatelet therapy, and thorough foot care. This article reviews the comprehensive diagnostic algorithm and medical treatment strategies for patients with infrainguinal PAD.

Nordic poles immediately improve walking distance in patients with intermittent claudication

OBJECTIVES

To investigate the immediate effects of Nordic pole walking (NPW) on walking distance and cardiopulmonary workload in patients with intermittent claudication.

METHODS

Using a standardised treadmill test (3.2 km h(-1) at 4% gradient), walking distance, cardiopulmonary responses, leg pain and perceived exertion during NPW were compared to responses evoked by normal walking in 20 patients with intermittent claudication. The distance to onset of claudication pain (claudication distance: CD) and to maximum walking distance (MWD), heart rate (HR), expired gas parameters, leg pain (Borg's CR-10 Scale) and perceived exertion (Borg's Rating of Perceived Exertion: RPE Scale) were compared.

RESULTS

CD increased significantly from a median (range) distance of 77 m (28-503) to 130 m (41-1080) and MWD increased significantly from 206 m (81-1078) to 285 m (107-1080) when patients used the Nordic poles (P=0.000). The level of leg pain at MWD was also significantly reduced during NPW (P=0.002). Perceived exertion at MWD did not increase despite an increase in cardiopulmonary work, as indicated by an increase in oxygen consumption (16.5%; P=0.000).

CONCLUSION

These results show that NPW immediately enables patients with intermittent claudication to walk further with less pain, despite a higher workload. NPW might also be a useful exercise strategy for improving the cardiovascular fitness of patients with intermittent claudication.

Effect of upper- and lower-limb exercise training on circulating soluble adhesion molecules, hs-CRP and stress proteins in patients with intermittent claudication

OBJECTIVES

To investigate the effects of exercise training on levels of circulating biomarkers associated with the progression of atherosclerosis and risk of cardiovascular events in patients with intermittent claudication.

METHODS

Circulating levels of soluble adhesion molecules (sVCAM-1, sICAM-1, sE-selectin), high sensitivity C-reactive protein (hs-CRP) and stress proteins (Hsp60 and Hsp70) in patients randomised to a 24-week programme of arm- or leg-cranking exercise were compared with those in usual care controls.

RESULTS

Arm and leg exercise similarly improved lower-limb aerobic exercise capacity (20% vs 19%, respectively; P<0.001) and maximum walking distance (30% vs 35%, respectively; P<0.001). Improvements in training limb-specific peak oxygen consumption were attenuated for patients in the highest vs lowest quartile for circulating sVCAM-1 levels at baseline (3% vs 25% respectively, P<0.001). Although circulating hs-CRP levels tended to be lower in the arm-cranking group (-1.55 [95% CI: -1.06 to -2.26]mgl(-1)), exercise training had no effect on circulating levels of soluble adhesion molecules or stress proteins.

CONCLUSIONS

These findings suggest that high levels of circulating sVCAM-1 are associated with an attenuated exercise training response and that arm-cranking exercise may provide an effective stimulus for evoking systemic anti-inflammatory adaptations in patients with intermittent claudication.

[Arterial obliterative disease and physical activity]

Regular physical exercise represents an essential element in treating patients with second-stage peripheral arterial occlusive disease. Peripheral arterial occlusive disease is a characteristic clinical manifestation of atherothrombotic processes. Its prevalence is 2-3%, consequently, it is estimated to be 200,000-300,000 patients in Hungary. Coronary artery disease and atherothrombosis of the carotid artery system may frequently coexist with peripheral arterial obliterative disease. Treatment of peripheral arterial obliterative disease influences their prevalence and prognosis as well. The main aim of regular physical exercise is to improve the quality of life of patients by increasing the functional capacity of the lower limbs. During exercise beneficial vascular changes occur like haemodynamic changes consisting of increasing pressure-gradient of stenotic artery and opening of collateral vessels, as well as improvement of the endothelial dysfunction. It favourably influences lipid profile by decreasing LDL cholesterol and increasing HDL cholesterol. Physical exercise beneficially affects blood rheology as well. It also brings about structural changes in the skeletal muscles, increases the enzyme levels in the oxidative metabolic processes and enhances the density of capillaries in the skeletal muscle fibres. According to the data published so far, patients with peripheral arterial obliterative disease are recommended to take part in supervised treadmill walking at least 3 days per week for 30-60 minutes each session containing 5-5 minute warm-up and cool-down periods. The training should be of intermittent intensity at the pain-free threshold. The physiological benefits are optimised at 3-6 months. The home-based training programme is also remarkably useful.

A comparison of treadmill and arm-leg ergometry exercise testing for assessing exercise capacity in patients with peripheral arterial disease

PURPOSE

To compare the results of treadmill exercise testing (TM) to arm-leg ergometry testing (AL) in patients with peripheral arterial disease (PAD).

METHODS

Twelve men and 8 women with PAD (mean age, 62 +/- 10 years) completed a treadmill test and an arm-leg ergometer exercise test. Oxygen uptake, heart rate, rate-pressure product (x10(-3)), ratings of claudication and perceived exertion, and power were measured.

RESULTS

Peak oxygen uptake, heart rate, and rate-pressure product were similar between TM and AL. Exercise duration was longer and the peak power higher on the AL than on the TM. Claudication pain > or =3/4 was the reason for test termination in all subjects during TM test and in 13 subjects during AL. Nine patients discontinued due to severe claudication on both tests, but the pain occurred later in AL than TM.

CONCLUSIONS

Although peak oxygen uptake was similar between the 2 exercise tests, patients with PAD exercised longer and to a higher peak power during the AL. These data suggest that the AL test may be used to evaluate peak exercise capacity in patients with PAD. The AL may also provide an alternate method for detecting PAD and coronary heart disease.

Heat Shock Proteins and the Resolution of Inflammation by Lymphocytes

Depletion of phagocytes that infiltrate host organs like the lungs reduces inflammatory damage to tissues. Understanding the mechanisms by which this process occurs could lead to new therapeutic approaches to limit the detrimental effects of inflammation. The lungs, gastrointestinal tract, and skin are particularly prone to infection. Specialized immune cells protect these organs from tissue damage by eliminating phagocytes from inflamed tissues by recognizing signals produced by the phagocytes. One such signal is heat shock proteins (HSP) expressed on the cell surface of phagocytes. These HSP closely resemble their microbial equivalents, and therefore phagocytes that are labeled by HSP are recognized as target cells. T lymphocytes bearing γδT cell receptor (TCR) elicit fast responses to invading pathogens. Since the γδTCR has limited germline-encoded diversity, HSP are an ideal target for recognition by these cells. γδT cells exert cytotoxic actions towards macrophages and neutrophils that express Hsp60 or Hsp70, respectively, on their cell surface. Through the recognition of HSP on the cell surface of inflamed cells, γδT cells eliminate phagocytes from inflammatory sites, thereby preventing host tissue damage