Supervised Exercise Therapy for Intermittent Claudication: A Propensity Score Matched Analysis of Retrospective Data on Long Term Cardiovascular Outcomes

OBJECTIVE

This study aimed to explore the long term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) vs. those who declined or prematurely discontinued SET, focusing on the incidence of chronic limb threatening ischaemia (CLTI), revascularisation, major adverse limb events (MALE), and major adverse cardiovascular events (MACE).

METHODS

A retrospective registry analysis of consecutive patients with IC who were referred for SET between March 2015 and August 2016 and followed up for a minimum of five years. Serial univariable analysis and logistic regression were performed to identify the statistically significant clinical variables that were independent predictors of each outcome measure. The resulting statistically significant variables were used to guide 1:1 propensity score matching (PSM) using the nearest neighbour method with a calliper of 0.2. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between SET and the outcomes of interest.

RESULTS

Two hundred and sixty-six patients were referred to SET between March 2015 and August 2016. Of these, 64 patients completed SET and 202 patients did not. After PSM, 49 patients were analysed in each cohort. The Cox proportional hazards analysis revealed a significant association between completion of SET and revascularisation requirement (HR 0.46 95% CI 0.25 - 0.84; p = .011), completion of SET and progression to CLTI (HR 0.091, 95% CI 0.04 - 0.24; p < .001), completion of SET and MACE (HR 0.52; 95% CI 0.28 - 0.99; p = .05) and completion of SET and MALE (HR 0.28, 95% CI 0.13 - 0.65; p = .003). The Harrell's C index for all of these models was greater than 0.75, indicating good predictive accuracy.

CONCLUSION

Completion of SET is associated with better outcomes in patients who completed SET compared with patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years.

A preoperative supervised exercise program potentially improves long-term survival after elective abdominal aortic aneurysm repair

OBJECTIVE

A preoperative supervised exercise program (SEP) improves cardiorespiratory fitness and perioperative outcomes for patients undergoing elective abdominal aortic aneurysm (AAA) repair. The aim of this study was to assess the effect of a preoperative SEP on long-term survival of these patients. A secondary aim was to consider long-term changes in cardiorespiratory fitness and quality of life.

METHODS

Patients scheduled for open or endovascular AAA repair were previously randomized to either a 6-week preoperative SEP or standard management, and a significant improvement in a composite outcome of cardiac, pulmonary, and renal complications was seen following SEP. For the current analysis, patients were followed up to 5 years post-surgery. The primary outcome for this analysis was all-cause mortality. Data were analyzed on an intention to treat (ITT) and per protocol (PP) basis, with the latter meaning that patients randomized to SEP who did not attend any sessions were excluded. The PP analysis was further interrogated using a complier average causal effect (CACE) analysis on an all or nothing scale, which adjusts for compliance. Additionally, patients who agreed to follow-up attended the research center for cardiopulmonary exercise testing and/or provided quality of life measures.

RESULTS

ITT analysis demonstrated that the primary endpoint occurred in 24 of the 124 participants at 5 years, with eight in the SEP group and 16 in the control group (P = .08). The PP analysis demonstrated a significant survival benefit associated with SEP attendance (4 vs 16 deaths; P = .01). CACE analysis confirmed a significant intervention effect (hazard ratio, 0.36; 95% confidence interval, 0.16-0.90; P = .02). There was no difference between groups for cardiorespiratory fitness measures and most quality of life measures.

CONCLUSIONS

These novel findings suggest a long-term mortality benefit for patients attending a SEP prior to elective AAA repair. The underlying mechanism remains unknown, and this merits further investigation.

Rehabilitation contributes to lower readmission rates for individuals with peripheral arterial disease: A retrospective observational study

BACKGROUND

Non-pharmacological interventions, such as rehabilitation, are crucial for the treatment of people with peripheral arterial disease (PAD). Although several studies have shown rehabilitation is effective in improving the functional prognosis of PAD, there is currently insufficient evidence regarding its effect on readmission rates.

OBJECTIVES

To examine the impact of rehabilitation on readmission rates for people with PAD.

METHODS

A retrospective analysis of the JMDC hospital database was performed on data from two groups of people aged ≥20 years who were hospitalized between 2014 and 2020 with PAD, as based on a previous diagnosis. Participants were divided according to whether they did, or did not, receive any form of rehabilitation as part of their treatment in hospital. The primary outcome was readmission rates at 30, 60, 90, and 180 days after initial admission. A one-to-one propensity score matching was used to compare readmission rates between rehabilitation and non-rehabilitation groups.

RESULTS

We included 13,453 people with PAD, of whom 2701 pairs (5402 subjects) were selected after being matched in the rehabilitation and non-rehabilitation groups. The rehabilitation group participants had significantly lower mortality and readmission rates at 30, 60, 90, and 180 days. The odds ratios (95% confidence interval) for both groups were 0.79 (0.69-0.91; 30 days), 0.81 (0.71-0.91; 60 days), 0.78 (0.69-0.88; 90 days), and 0.79 (0.71-0.88; 180 days).

CONCLUSIONS

This large, nationwide study found that rehabilitation treatment during hospitalization was associated with lower readmission rates and mortality for people following hospitalization with PAD and supports its inclusion as a standard PAD treatment.

Walking Training Increases microRNA-126 Expression and Muscle Capillarization in Patients with Peripheral Artery Disease

Patients with peripheral artery disease (PAD) have reduced muscle capillary density. Walking training (WT) is recommended for PAD patients. The goal of the study was to verify whether WT promotes angiogenesis in PAD-affected muscle and to investigate the possible role of miRNA-126 and the vascular endothelium growth factor (VEGF) angiogenic pathways on this adaptation. Thirty-two men with PAD were randomly allocated to two groups: WT (n = 16, 2 sessions/week) and control (CO, n = 16). Maximal treadmill tests and gastrocnemius biopsies were performed at baseline and after 12 weeks. Histological and molecular analyses were performed by blinded researchers. Maximal walking capacity increased by 65% with WT. WT increased the gastrocnemius capillary-fiber ratio (WT = 109 ± 13 vs. 164 ± 21 and CO = 100 ± 8 vs. 106 ± 6%, p < 0.001). Muscular expression of miRNA-126 and VEGF increased with WT (WT = 101 ± 13 vs. 130 ± 5 and CO = 100 ± 14 vs. 77 ± 20%, p < 0.001; WT = 103 ± 28 vs. 153 ± 59 and CO = 100 ± 36 vs. 84 ± 41%, p = 0.001, respectively), while expression of PI3KR2 decreased (WT = 97 ± 23 vs. 75 ± 21 and CO = 100 ± 29 vs. 105 ± 39%, p = 0.021). WT promoted angiogenesis in the muscle affected by PAD, and miRNA-126 may have a role in this adaptation by inhibiting PI3KR2, enabling the progression of the VEGF signaling pathway.

WalkingPad protocol: a randomized clinical trial of behavioral and motivational intervention added to smartphone-enabled supervised home-based exercise in patients with peripheral arterial disease and intermittent claudication

Background

Physical exercise is a first-line treatment for peripheral arterial disease (PAD) and intermittent claudication (IC) reducing pain and increasing the distances walked. Home-based exercise therapy (HBET) has the advantage of reaching a higher number of patients and increasing adherence to physical exercise as it is performed in the patient’s residential area and does not have the time, cost, and access restrictions of supervised exercise therapy (SET) implemented in a clinical setting. Even so, rates of adherence to physical exercise are relatively low, and therefore, m-health tools are promising in increasing motivation to behavior change and adherence to physical exercise. A built-in virtual assistant is a patient-focused tool available in a mobile interface, providing a variety of functions including health education, motivation, and implementation of behavior change techniques.

Methods

This is a single-center, prospective, three-arm, single-blind, randomized, controlled, superior clinical trial with stratified and blocked random allocation. Three hundred participants with PAD and IC will be recruited from an Angiology and Vascular Surgery Department, Centro Hospitalar Universitário Porto (CHUPorto), Porto, Portugal. All patients will receive the same medical care recommended by  current guidelines. Participants in all three groups will receive a personalized prescription for an HBET program and a behavioral change and motivational intervention. Participants in experimental groups 1 and 2 will receive a smartphone with the WalkingPad app to monitor exercise sessions. Experimental group 2 WalkingPad app will have a built-in virtual assistant that will promote behavioral change and provide motivational support. Participants allocated to the active control group will not receive the m-health tool, but a practice diary to encourage monitoring. The  program will last for 6 months with three evaluation moments (baseline, 3, and 6 months). The primary outcome will be the change in distances walked (maximal and pain-free) from baseline to 3 and 6 months. Secondary outcomes will be changes in quality of life, patients’ perception of resistance, and walking speed.

Discussion

This study will allow measuring the effectiveness of an m-health tool in increasing motivation for behavior change and adherence to an HBET program in patients with PAD. The superiority of experimental group 2 in the primary and secondary outcomes will indicate that the virtual assistant is effective for motivating behavioral change and encouraging the practice and adherence to physical exercise. The use of m-health tools and virtual health assistants can potentially fill a gap in the access and quality of health services and information, reducing the burden on the health system and promoting self-management and self-care in chronic illness.

Trial registration

ClinicalTrials.govNCT04749732. Registered on 10 February 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06279-9.

Implementation of supervised exercise therapy in a veteran population with symptomatic claudication

Background:

Real-world implementation of supervised exercise therapy (SET) referral for symptomatic intermittent claudication has been limited by poor provider awareness around reimbursement and low patient adherence owing to factors including limited center availability and long travel distances to sites.

Methods:

In this study, 76 of 77 consecutive male veteran patients with intermittent claudication managed at a single-center vascular specialty clinic were referred to SET prior to revascularization. Pre- and post-SET submaximal exercise treadmill testing was performed for assessment of exercise capacity in metabolic equivalents (METs).

Results:

In the 48.7% of subjects who completed 36 sessions of SET ( n = 37), the average improvement in METs was 60.3%, reflecting improvement from baseline average of 3.4 METs to 5.5 METs after SET. Another 14 patients pursued self-guided exercise therapy and 25 patients declined any participation in exercise therapy. Reasons for declining participation in SET included inadequate transportation, cost of copayment, and interference with full-time work schedules. There was a nonsignificant numeric trend toward improved change in ankle–brachial index in the combined SET and self-guided exercise groups compared to those that declined exercise therapy (0.011 ± 0.124 vs –0.040 ± 0.105, p = 0.156).

Conclusion:

High acceptance of referral to SET is possible, despite the limitations to implementation. Incorporation of novel pre- and post-SET submaximal exercise treadmill testing allows for assessment of change in exercise capacity and aids in risk stratification and management of intermittent claudication symptoms.

Catheter based interventions for lower extremity peripheral artery disease

The field of peripheral arterial intervention has exploded over the past 20 years. Current knowledge includes a growing evidence base for treatment as well as a myriad of new interventional approaches to complex disease. This review seeks to outline the current state of the art for interventional approaches to lower extremity peripheral arterial disease.

Cardiac Rehabilitation in German Speaking Countries of Europe-Evidence-Based Guidelines from Germany, Austria and Switzerland LLKardReha-DACH-Part 2

Background: Scientific guidelines have been developed to update and harmonize exercise based cardiac rehabilitation (ebCR) in German speaking countries. Key recommendations for ebCR indications have recently been published in part 1 of this journal. The present part 2 updates the evidence with respect to contents and delivery of ebCR in clinical practice, focusing on exercise training (ET), psychological interventions (PI), patient education (PE). In addition, special patients’ groups and new developments, such as telemedical (Tele) or home-based ebCR, are discussed as well. Methods: Generation of evidence and search of literature have been described in part 1. Results: Well documented evidence confirms the prognostic significance of ET in patients with coronary artery disease. Positive clinical effects of ET are described in patients with congestive heart failure, heart valve surgery or intervention, adults with congenital heart disease, and peripheral arterial disease. Specific recommendations for risk stratification and adequate exercise prescription for continuous-, interval-, and strength training are given in detail. PI when added to ebCR did not show significant positive effects in general. There was a positive trend towards reduction in depressive symptoms for “distress management” and “lifestyle changes”. PE is able to increase patients’ knowledge and motivation, as well as behavior changes, regarding physical activity, dietary habits, and smoking cessation. The evidence for distinct ebCR programs in special patients’ groups is less clear. Studies on Tele-CR predominantly included low-risk patients. Hence, it is questionable, whether clinical results derived from studies in conventional ebCR may be transferred to Tele-CR. Conclusions: ET is the cornerstone of ebCR. Additional PI should be included, adjusted to the needs of the individual patient. PE is able to promote patients self-management, empowerment, and motivation. Diversity-sensitive structures should be established to interact with the needs of special patient groups and gender issues. Tele-CR should be further investigated as a valuable tool to implement ebCR more widely and effectively.

Factors Associated With Change in Cardiovascular Fitness for Patients With Peripheral and Coronary Artery Disease in Cardiac Rehabilitation

PURPOSE

Cardiac rehabilitation (CR) yields improvements in cardiorespiratory fitness (peak oxygen uptake [V˙o2peak]). Predictors of change in V˙o2peak have been reported among patients with coronary artery disease (CAD) but have not been compared with peripheral artery disease (PAD). This study determined predictors of improved V˙o2peak among patients with PAD, CAD, and concomitant PAD and CAD (PAD/CAD) following a 6-mo home-based outpatient CR program (1supervised and 4 home weekly sessions).

METHODS

This study was a retrospective (2006-2017) multiple linear regression analysis of CR patients with PAD (n = 63), CAD (n = 63), and PAD/CAD (n = 164). Peripheral artery disease and CAD were matched for age, sex, smoking status, diabetes, and year in program.

RESULTS

Mean age of all patients was 68.9±10.1 yr, 72% were male, and mean improvement in V˙o2peak was 2.1 ± 3.3 mL/kg/min (14.5% improvement) following CR. In CAD, younger age (β = .30, P = .015), male sex (β = -.29, P = .019), and more recent year of entry (β = .26, P = .035) were predictors of improved V˙o2peak. In PAD, only male sex (β = -.36, P = .004) and in PAD/CAD, not having diabetes (β = -.24, P = .002), not smoking (β = -.25, P = .001), and shorter elapsed time from referring diagnosis to entry (β = -.19, P = .016) were predictors.

CONCLUSIONS

While younger age and male sex were predictors of improved V˙o2peak in CAD, age did not influence PAD, and neither age nor sex influenced PAD/CAD. Peripheral artery disease-related limitations may override some demographic factors, and strategies for improving V˙o2peak should be explored. Managing smoking and comorbid diagnoses including diabetes and a timely entry to CR may yield greater improvements in V˙o2peak among individuals with PAD.

Effects of supervised exercise therapy on blood pressure and heart rate during exercise, and associations with improved walking performance in peripheral artery disease: Results of a randomized clinical trial

OBJECTIVE

Supervised exercise therapy (SET) improves walking ability in people with peripheral artery disease (PAD). However, the effects of SET on cardiovascular health in PAD remain unclear. Using data from a randomized clinical trial, this post hoc analyses investigated the effects of a 6-month SET intervention, compared with a control group, on changes in blood pressure (BP) and heart rate (HR) during a graded treadmill exercise test in people with PAD.

METHODS

We randomized 210 participants with PAD to either SET (3× weekly) or control (1× weekly health lectures) for 6 months. A graded treadmill exercise test, 6-minute walk test, and Walking Impairment Questionnaire were completed at baseline and the 6-month follow-up. BP and HR were measured at the end of each 2-minute stage of the graded treadmill exercise test. Mixed effects regression models compared the overall mean 6-month change in systolic BP, diastolic BP, pulse pressure (PP), and HR during the first 5 stages of the graded treadmill exercise test between groups.

RESULTS

Of the 210 randomized participants with PAD, 176 (67 ± 9 years; 72 [41%] female, 115 [65%] Black) completed the graded treadmill exercise test at baseline and the 6-month follow-up. Compared with the control group at the 6-month follow-up, SET significantly decreased overall mean systolic BP (-12 mm Hg; P < .001), PP (-9 mm Hg; P < .001), and HR (-7 b/min; P < .01) during a graded treadmill exercise test but not diastolic BP. Among participants randomized to SET, a greater decrease in systolic BP, PP, and HR during a graded treadmill exercise test was significantly associated with a greater improvement in 6-minute walk distance (systolic BP, r = -0.19 [P = .03] and PP, r = -0.23 [P < .01]; and HR, r = -0.21 [P < .01]) and with maximal treadmill walking distance (systolic BP, r = -0.21 [P < .01] and PP, r = -0.17 [P = .03]) at the 6-month follow-up. A greater decrease in the HR during a graded treadmill exercise test was significantly associated with a better WIQ distance score (r = -0.27; P = .03) at the 6-month follow-up.

CONCLUSIONS

In people with PAD, compared with a control group, SET improved cardiovascular health, measured by changes in BP and HR during exercise. The degree of improvement in cardiovascular health correlated with the degree of improvement in walking performance in people with PAD. NCT: 01408901.

Clinical considerations after endovascular therapy of peripheral artery disease

Introduction: Patients with peripheral artery disease (PAD) are at higher risk for all-cause mortality, driven by increased cardiovascular mortality rates. In this manuscript we review the literature on guideline-recommended therapies and discuss the major clinical considerations after endovascular therapy of PAD.Areas covered: Current guidelines recommend smoking cessation, aspirin, statin, and renin-angiotensin system inhibitors in order to reduce the risk of cardiovascular and limb-related adverse events. Nonetheless, studies have shown that patients with PAD are undertreated with these important medical therapies. Additionally, there is lack in evidence regarding the most optimal follow up imaging approach for early detection of disease recurrence and re-intervention among patients undergoing endovascular therapy for PAD. We also describe the benefits of supervised walking exercise for patients with PAD that undergo revascularization procedures and are fit for such interventions.Expert opinion: Adherence to guideline recommended medical therapy is crucial for improved outcomes in PAD management. Systematic assessment of risk-reduction interventions could help increase adherence to clinically beneficial interventions and improve the overall prognosis of patients with PAD undergoing revascularization procedures. Additionally, optimization of current follow up protocols is needed, with the optimal goal to develop standardized cost-effective algorithms regarding early detection of disease recurrence and re-intervention.

Cardiac rehabilitation with intermittent myocardial ischaemia as a new therapeutic option in refractory angina?

A 72-year-old man daily suffered from a refractory angina consecutive to a diffuse coronary artery disease despite optimal medical management. Revascularization could not be performed because of a severe thrombopenia. He was referred to our outpatient cardiac rehabilitation programme where he was candidate for 20 sessions, three times a week, of high-intensity aerobic interval training involving brief episodes of regressive myocardial ischaemia. After 7 weeks, exercise capacity (+28.5%), VO₂ peak (35.7%), and ischaemic threshold increased while clinical status and quality of life improved. No adverse effect was reported. Aerobic interval training with myocardial ischaemia might be a therapeutic alternative in refractory angina.

Peripheral Artery Disease in Diabetes Mellitus: Focus on Novel Treatment Options

Diabetes mellitus (DM) and peripheral artery disease (PAD) are two clinical entities closely associated. They share many pathophysiological pathways such as inflammation, endothelial dysfunction, oxidative stress and pro-coagulative unbalance. Emerging data focusing on agents targeting these pathways may be promising. Moreover, due to the increased cardiovascular risk, there is a growing interest in cardiovascular and "pleiotropic" effects of novel glucose lowering drugs. This review summarizes the main clinical features of PAD in patients, the diagnostic process and current medical/interventional approaches, ranging from "classical treatment" to novel agents.

Impact of aerobic exercise type on blood flow, muscle energy metabolism, and mitochondrial biogenesis in experimental lower extremity artery disease

Exercise training (ET) is recommended for lower extremity artery disease (LEAD) management. However, there is still little information on the hemodynamic and metabolic adaptations by skeletal muscle with ET. We examined whether hindlimb perfusion/vascularization and muscle energy metabolism are altered differently by three types of aerobic ET. ApoE^−/− mice with LEAD were assigned to one of four groups for 4 weeks: sedentary (SED), forced treadmill running (FTR), voluntary wheel running (VWR), or forced swimming (FS). Voluntary exercise capacity was improved and equally as efficient with FTR and VWR, but remained unchanged with FS. Neither ischemic hindlimb perfusion and oxygenation, nor arteriolar density and mRNA expression of arteriogenic-related genes differed between groups. ¹⁸FDG PET imaging revealed no difference in the steady-state levels of phosphorylated ¹⁸FDG in ischemic and non-ischemic hindlimb muscle between groups, nor was glycogen content or mRNA and protein expression of glucose metabolism-related genes in ischemic muscle modified. mRNA (but not protein) expression of lipid metabolism-related genes was upregulated across all exercise groups, particularly by non-ischemic muscle. Markers of mitochondrial content (mitochondrial DNA content and citrate synthase activity) as well as mRNA expression of mitochondrial biogenesis-related genes in muscle were not increased with ET. Contrary to FTR and VWR, swimming was ineffective in improving voluntary exercise capacity. The underlying hindlimb hemodynamics or muscle energy metabolism are unable to explain the benefits of running exercise.

Effect of Exercise Training on Exercise Tolerance and Level of Oxidative Stress for Head and Neck Cancer Patients Following Chemotherapy

Background

Chemotherapy decreases fitness performance via repression of cardiopulmonary function and oxidative stress. This study was designed to investigate whether exercise intervention could improve exercises capacity and reduce systemic oxidative stress in patients with head and neck (H&N) cancer receiving chemotherapy.

Methods

This is a single-center study. Forty-two H&N cancer patients who were undergoing chemotherapy were recruited in this study. An 8-week exercise intervention was performed by conducting the combination of aerobic and resistance exercise 3 days a week. The exercise training was conducted by a physiotherapist. The exercise capacity and exercise responses were measured from blood pressure (BP) and heart rate (HR). Oxidative stress markers from human plasma, such as total antioxidant capacity, 8-hydroxy-2'-deoxyguanosine, malondialdehyde, and carbonyl content, were tested by activity kits.

Results

We provide compelling evidence that exercise training ameliorated exercise responses and increased exercise capacity by repressing resting BP and increasing 1- and 3-min BP recovery. We also found the resting HR was reduced, and the 1- and 3-min HR recovery was increased after exercise training. In addition, the rating of perceived exertion after the peak exercise was reduced after exercise intervention. We also found that exercise training repressed oxidative stress markers by elevation of total antioxidant capacity and suppression of 8-OHd and carbonyl content in plasma.

Discussion

We clearly demonstrate that exercise can promote exercise capacity and reduce oxidative stress in H&N cancer patients receiving chemotherapy, which might guide new therapeutic approaches for cancer patients, especially those undergoing chemotherapy.

Cardiovascular Responses during and after Maximal Walking in Men and Women with Symptomatic Peripheral Artery Disease

BACKGROUND

Walking is recommended for patients with peripheral arterial disease (PAD). It has been shown that patients with PAD present sharper increases in blood pressure (BP) and heart rate (HR) during maximal walking when compared with healthy subjects. Additionally, women with PAD present a worse physiological profile, and it is possible that they may present higher cardiovascular load during and after a bout of maximal walking than men. Thus, the objective of this study was to compare cardiovascular and autonomic responses during and after maximal walking between men and women with PAD and intermittent claudication (IC).

METHODS

Forty patients with PAD and IC (20 men and 20 women) underwent, in random order, 2 sessions: control (standing on treadmill) and exercise (maximal treadmill walking test with Gardner's protocol). During the exercise, HR and BP were measured. Before and after the sessions, cardiovascular variables (BP HR, cardiac output, peripheral vascular resistance, and stroke volume) and autonomic modulation (HR and BP variabilities and baroreflex sensitivity) were assessed. In addition, an ambulatory BP monitoring was recorded after each session.

RESULTS

Men and women presented similar maximal walking capacity. During the walking test, HR and systolic BP increased similarly in men and women. After the maximal walking, cardiovascular and autonomic responses did not differ between the genders. In addition, postintervention ambulatory BP parameters were also similar in men and women. Therefore, in men and women, maximal walking similarly reduced clinic systolic BP and stroke volume, and increased HR and total power of HR variability during the recovery period.

CONCLUSIONS

Men and women with PAD and IC present similar cardiovascular and autonomic responses during and after maximal walking.

Changes in exercise capacity and risk of all-cause mortality in patients with peripheral artery disease: a 10-year retrospective cohort study

We retrospectively studied the association between changes in exercise capacity at discharge from a home-based exercise program and the risk of all-cause mortality among patients with peripheral artery disease (PAD) and claudication. The records of 1076 consecutive PAD patients were assessed between 2003 and 2013. The exercise program was prescribed during a few visits and executed at home at symptom-free walking speed. Ankle-Brachial Index (ABI) and maximal speed (S_max) on an incremental treadmill test were recorded at baseline and discharge. The number and date of deaths and hospitalizations for a 10-year period were collected from the regional registry. A total of 865 PAD patients completed the program (completers), while 221 left the program for health reasons (n = 128, diseased) or for nonhealth reasons (n = 83, quitters). Among the completers, the mortality rate (27%) was significantly lower (p < 0.001) than that of both the diseased (49 deaths, 38%) and the quitters (45 deaths, 54%). The completers (71 ± 9 years; 88% exercise sessions completed) showed significant improvements in the lowest ABI (from 0.62 ± 0.18 to 0.67 ± 0.19) and S_max (from 3.3 ± 1.1 to 3.8 ± 1.1 km h^-1) at discharge. The completers who reached the clinically important difference of S_max ≥ 0.4 km h^-1 at follow-up showed a significantly lower mortality risk (25% vs. 30%; HR 0.72; 95% CI 0.55-0.93) as well a lower rate of hospitalizations (p < 0.001). In conclusion, in PAD patients, active participation in a home-based exercise program was associated with a lower rate of death and better long-term clinical outcomes, particularly for those who attained a moderate increase in exercise capacity.

Entering Cardiac Rehabilitation With Peripheral Artery Disease: A RETROSPECTIVE COMPARISON TO CORONARY ARTERY DISEASE

PURPOSE

Supervised exercise is recommended for patients with peripheral artery disease (PAD) and patients with coronary artery disease (CAD). Both conditions share common etiology as atherosclerotic diseases. The clinical profile, cardiorespiratory fitness, and exercise prescriptions of PAD, CAD, and patients with concomitant PAD and CAD (BOTH) have yet to be compared upon entry into cardiac rehabilitation (CR).

METHODS

Cardiopulmonary, demographic, and anthropometric assessments were conducted at entry to CR between January 2006 and December 2017.

RESULTS

Among 9701 consecutively enrolled patients, there were 94.6% with CAD (n = 9179), 1.5% with PAD (n = 143), and 3.9% with BOTH (n = 379). Only 5.4% (n = 522) of all patients entering CR had a diagnosis of PAD. Compared with CAD, patients with PAD and BOTH were older (mean ± SD = 62.5 ± 11.1 vs 67.9 ± 11.4 and 69.2 ± 9.8 yr, P < .01), had higher resting systolic blood pressure (124 ± 17 vs 130 ± 17 and 133 ± 18 mm Hg, P < .01), had lower cardiorespiratory fitness (19.7 ± 6.3 vs 15.6 ± 4.8 and 15 ± 4.5 mL/kg/min, P < .01), and were more likely to have diabetes (25% vs 35% and 41%, P < .01), abdominal obesity (39% vs 54% and 51%, P < .01), and initially prescribed lower-intensity exercise (84.4 ± 14.1 vs 74.1 ± 15.7 and 70.0 ± 14.6 m/min exercise pace, P < .01), reflecting the complex nature of patients diagnosed with PAD.

CONCLUSIONS

Patients referred with PAD have a cardiovascular risk profile that places them at a greater risk for a repeat or first cardiac event compared with patients with CAD. Referral to structured exercise and risk factor modification programs should be considered to aid in the management of PAD.

Cardiac rehabilitation in older adults: New options

Cardiac rehabilitation (CR) is an important component in the continuum of care for patients with cardiovascular diseases, including the older population. Benefits of CR which include mortality benefit, decreased hospitalizations, increased functional capacity all extend to an older population. In Medicare beneficiaries which represent an older population, utilization of CR continues to remain low despite evidence that suggests lower hospitalization rates, Medicare costs, and improved symptoms. Given poor referral rates, enrollment rates, and completion rates, a call for new strategies has been made by all major societies. However, several barriers exist. Newer models of CR constructed to overcome these barriers are reviewed below. Some of these new strategies include alternative site CR or home‐based CR and the utilization of technology.

Low-Intensity Exercise Training Increases Heart Rate Variability in Patients With Peripheral Artery Disease

Patients with peripheral artery disease (PAD), consistent with others with atherosclerotic occlusive disorders, have autonomic dysfunction (as measured by low heart rate variability [HRV]) that predisposes them to sympathetically mediated cardiac arrhythmias and sudden death. Exercise therapy has been shown to increase HRV in patients with coronary artery disease by increasing parasympathetic modulation of heart rate. This study quantified the circulatory and autonomic effects of a progressive, 12-week home-based, low-intensity (pain-free walking) exercise program in PAD and intermittent claudication. Participants (N = 33, mean age 67.8 8.1 years) were randomly assigned to either a walking group (n = 18), whose members performed a structured, 12-week, progressive walking program 5 days/week for 12 weeks, or a comparison group (n = 15), whose members performed usual activities. Circulatory measures (heart rate, blood pressure, and rate pressure product) and autonomic measures (HRV) were obtained at the beginning (Week 1) and end (Week 12) of the study. Minimal change in circulatory measures occurred. However, spectral analysis of HRV revealed that autonomic function improved significantly in members of the walking group; specifically, there was an increase in parasympathetic and a decrease in sympathetic modulation. Members of the walking group also significantly increased maximal walking distance. These findings suggest that a structured, low-intensity, high-frequency walking program improves autonomic function by increasing HRV in patients with PAD.

National survey of current practice and opinions on rehabilitation for intermittent claudication in the Danish Public Healthcare System

Objective. International guidelines recommend rehabilitation including supervised exercise therapy in patients with Intermittent Claudication (IC), but knowledge of the implementation in clinical practice is limited. This study aims to investigate current practice and opinions on rehabilitation for patients with IC among vascular surgeons and rehabilitation departments in the municipalities and hospitals. Design. Three electronic cross-sectional surveys were distributed nationally to the Danish vascular surgeons (n = 131) and to rehabilitation departments in the municipalities (n = 92) and hospitals (n = 33). Results. The response rates were 70% among the vascular surgeons, 98% among the municipalities and 94% among the hospitals. Vascular surgeons utilize oral advice to exercise by self-administered walking, pharmacological treatment, and revascularization to improve walking distance in patients with IC. Currently, only 12% of the vascular surgeons referred to rehabilitation to improve walking distance, while almost all vascular surgeons (96%) would refer their patients to IC rehabilitation, if it was available. Only 14% of municipalities and none of the hospitals, who treat patients with IC, have a rehabilitation program designed specifically for patients with IC. However, 59% of the rehabilitation departments in the municipalities and 26% in the hospitals included patients with IC in rehabilitation program designed for other patient groups - mostly cardiac patients. There was consensus among the groups of respondents that future IC specific rehabilitation should include an initial conversation, supervised exercise therapy, smoking cessation, and patient education according to guidelines. Conclusion. Vascular surgeons support referral and participation in IC rehabilitation to improve walking distance in patients with IC. Despite some hospitals and municipalities included patients with IC in rehabilitation nearly all services fail to meet current guideline as specific services tailored to patient with IC is almost non-existent in Denmark. Our findings call for action for services to comply with current recommendations of structured, systematic rehabilitation for patients with IC.

The Impact of Supervised Exercise Training on Traditional Cardiovascular Risk Factors in Patients With Intermittent Claudication: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with intermittent claudication (IC) are at increased risk of cardiovascular (CV) morbidity and mortality. Whereas extensive evidence supports the beneficial effects of supervised exercise training (SET) on walking capacity, little is known about the effect of SET on the CV risk profile of IC patients. Therefore, the aim was to evaluate the effects of SET on CV risk factors in IC patients by using meta-analysis techniques.

METHODS

A systematic search in the electronic databases MEDLINE, EMBASE, CINAHL, and CENTRAL was conducted from the earliest date available until October 2, 2018. Randomised and non-randomised controlled trials lasting ≥ four weeks and investigating the effect of SET on CV risk factors in IC patients were included. Traditional CV risk factors were studied as primary outcomes; pain free walking distance (PFWD) and maximum walking distance (MWD) were included as secondary outcomes. Data were pooled using random effects models with summary data reported as weighted means and 95% confidence interval (CIs).

RESULTS

Fifteen trials were included, involving 18 study groups (nine walking, four resistance, two aerobic training, and three combined groups), totalling 725 patients (mean age 66.3 years; mean ankle brachial index, 0.64). Exercise reduced systolic blood pressure (-5.8 mmHg; CI -9.89 to 1.67, p < .01) whereas all other CV risk factors (i.e., body weight, body mass index, diastolic blood pressure, and blood lipids) remained statistically unaltered. Exercise also improved PFWD (+132 m; CI 70-194, p < .001) and MWD (+183 m; CI 98-268, p < .001).

CONCLUSION

This meta-analysis supports the beneficial effects of SET on walking capacity. Little evidence for an improvement of the CV risk profile was found following exercise in patients with IC. However, given the scarcity of data, high quality RCTs that include an assessment of CV risk factors are urgently required to determine the effect of exercise therapy in the secondary prevention of CV disease of IC patients.

Beneficial Effect of Exercise on Cognitive Function during Peripheral Arterial Disease: Potential Involvement of Myokines and Microglial Anti-Inflammatory Phenotype Enhancement

Peripheral arterial disease (PAD), leading to intermittent claudication, critical ischemia with rest pain, and/or tissue damage, is a public health issue associated with significant morbidity and mortality. Little is known about the link between PAD, cognitive function, and whether exercise might reduce cognitive dysfunction in PAD patients, as previously observed concerning both quality of life and prognosis. This review highlights the fact that patients suffering from PAD often demonstrate cognitive dysfunction characterized by reduced performance in nonverbal reasoning, reduced verbal fluency, and decreased information processing speed and a greater risk for progression toward dementia. Further, the data presented support that physical exercise, likely through myokine secretion and microglial anti-inflammatory phenotype enhancement, might participate in the cognition protection in common clinical settings.

A systematic review and meta-analysis of the effects of supervised exercise therapy on modifiable cardiovascular risk factors in intermittent claudication

OBJECTIVE

Cardiovascular events, such as myocardial infarction and stroke, contribute significantly to the prognosis of patients with peripheral artery disease. Therefore cardiovascular risk reduction is a vital element of treatment in patients with intermittent claudication (IC). The cardiovascular risk is largely determined by modifiable risk factors, which can be treated with medical care and lifestyle adjustments, such as increasing physical activity. The objective of this study was to determine the effects of supervised exercise therapy (SET) on modifiable cardiovascular risk factors in IC patients.

METHODS

This is a systematic review and meta-analysis of prospective studies on the effects of SET on cardiovascular risk factors in symptomatic IC patients. Studies were eligible if they presented baseline and follow-up values for at least one of the following risk factors: blood pressure (systolic or diastolic), heart rate, lipid profile (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol), glucose, glycated hemoglobin, body weight, body mass index, or cigarette smoking. Pooled mean differences between follow-up and baseline were analyzed using a random-effects model. Data were classified into short-term results (6 weeks-3 months) and midterm results (6-12 months). Statistical heterogeneity was presented as I² and Q statistic.

RESULTS

Twenty-seven studies with a total of 808 patients were included in this review. In the short term, SET resulted in significant improvements of systolic blood pressure (decrease of 4 mm Hg; 10 studies; 95% confidence interval [CI], -6.40 to -1.76; I², 0%) and diastolic blood pressure (decrease of 2 mm Hg; 8 studies; 95% CI, -3.64 to -0.22; I², 35%). In the midterm, SET contributed to significant lowering of levels of low-density lipoprotein cholesterol (decrease of 0.2 mmol/L; four studies; 95% CI, -0.30 to -0.12; I², 29%) and total cholesterol (decrease of 0.2 mmol/L, four studies; 95% CI, -0.38 to -0.10; I², 36%). No significant effects of SET were identified for heart rate, triglycerides, high-density lipoprotein cholesterol, glucose, glycated hemoglobin, body weight, body mass index, or cigarette smoking.

CONCLUSIONS

This systematic review and meta-analysis shows favorable effects of SET on modifiable cardiovascular risk factors, specifically blood pressure and cholesterol levels. Despite the moderate quality, small trial sample sizes, and study heterogeneity, these findings support the prescription of SET programs not only to increase walking distances but also for risk factor modification. Future studies should address the potential effectiveness of SET to promote a healthier lifestyle and to improve cardiovascular outcomes in patients with claudication.

Rehabilitative Exercise Reduced the Impact of Peripheral Artery Disease on Vascular Outcomes in Elderly Patients with Claudication: A Three-Year Single Center Retrospective Study

The study retrospectively evaluated the association between rehabilitative outcomes and risk of peripheral revascularizations in elderly peripheral artery disease (PAD) patients with claudication. Eight-hundred thirty-five patients were enrolled. Ankle-brachial index (ABI) and maximal walking speed (S_max) were measured at baseline and at discharge from a structured home-based rehabilitation program. For the analysis, patients were divided according to a baseline ABI value (severe: ≤0.5; moderate: ≥0.5) and according to hemodynamic or functional rehabilitative response (responder: ABI ≥ 0.10 and/or S_max > 0.5 km/h). Three-year outcomes were collected from the regional registry. According to the inclusion criteria (age 60–80, ABI < 0.80; program completion) 457 patients, 146 severe and 311 moderate, were studied. The whole population showed significant functional and hemodynamic improvements at discharge, with 56 revascularizations and 69 deaths at follow-up. Compared to the moderate group, the severe group showed a higher rate of revascularizations (17% vs. 10%, p < 0.001) and deaths (29% and 8%, respectively; p < 0.001). However, patients with severe PAD who were ABI responders after rehabilitation showed less revascularizations than non-responders (13% vs. 21%; hazard ratio (HR): 0.52) and were not different from patients with moderate disease (9%). Superimposable rates were observed for S_max responders (13% vs. 21%; HR: 0.55; moderate 10%). In conclusion, elderly patients with severe PAD empowered by better rehabilitation outcomes showed lower rates of peripheral revascularizations and deaths that were comparable to patients with moderate PAD.

Research Toolbox for Peripheral Arterial Disease - Minimally Invasive Assessment of the Vasculature and Skeletal Muscle

In 2010, more than 200 million people were afflicted with peripheral arterial disease (PAD). Because it is atherosclerotic in etiology, it is not surprising that PAD is a leading cause of cardiovascular morbidity. Cardiovascular disease (CVD) risk can be decreased if ambulatory physical function is improved. However, physical function is limited by a mismatch between oxygen supply and demand in the legs, which results in exertional pain, leg weakness, and balance problems. Therefore, a key factor for improving physical function, and decreasing CVD outcomes, is ensuring oxygen supply meets the oxygen demand. The purpose of this review is to highlight and evaluate practical and minimally invasive tools for assessing PAD etiology, with a specific focus on tools suited to studies focusing on improving physical function and CVD outcomes. Specifically, the macrovascular, microvascular, and skeletal muscle pathology of PAD is briefly outlined. Subsequently, the tools for assessing each of these components is discussed, including, where available, the evidence to contextualize these tools to PAD pathology as well as physical function and CVD outcomes. The goal of this review is to guide researchers to the appropriate tools with respect to their methodological design.

Cardiovascular and all-cause mortality in patients with intermittent claudication and critical limb ischaemia

BACKGROUND

The aim of this study was to evaluate absolute mortality risks and to determine whether changes in mortality risk occurred in patients with intermittent claudication (IC) or critical limb ischaemia (CLI) in the Netherlands between 1998 and 2010.

METHODS

Data for patients treated between 1998 and 2010 were obtained from Dutch nationwide registers: the Hospital Discharge Register, Population Register and Cause of Death Register. The registers were used to obtain information regarding IC and CLI hospitalizations, co-morbidities, demographic factors, and date and cause of death. The cohort was split into two time intervals for comparison: 1998-2004 (period 1) and 2005-2010 (period 2). Thirty-day mortality was excluded to eliminate per-admission complications. One- and 5-year cardiovascular and all-cause mortality rates were compared with those of a representative sample of the general Dutch population (28 494 persons) by Cox proportional hazards models.

RESULTS

Some 47 548 patients were included, 34 078 with IC and 13 470 with CLI. In patients with IC, the age-adjusted 5-year mortality risk for cardiovascular disease decreased significantly in period 2 (14·1 per cent) compared with that in period 1 (16·1 per cent) in men only (5-year adjusted hazard ratio (HR) 0·76, 95 per cent c.i. 0·69 to 0·83; P < 0·001). In patients with CLI, the cardiovascular mortality risk decreased significantly only in women, with the 5-year risk reducing from 31·2 per cent in period 1 to 29·2 per cent in period 2 (adjusted HR 0·84, 0·74 to 0·94; P = 0·004). Compared with the general population, the mortality risk in patients with IC was increased between 1·70 (1·58 to 1·83) and 3·20 (2·69 to 3·81) times, and in those with CLI the risk was increased between 2·24 (2·09 to 2·40) and 5·19 (4·30 to 6·26) times.

CONCLUSION

The risk of premature death in patients with IC and CLI declined significantly in the Netherlands, in a sex-specific manner, over the period from 1998 to 2010. The absolute risk of cardiovascular mortality remains high in these patients.

Walking training at the heart rate of pain threshold improves cardiovascular function and autonomic regulation in intermittent claudication: A randomized controlled trial

OBJECTIVES

This study investigated the effects of walking training (WT) on cardiovascular function and autonomic regulation in patents with intermittent claudication (IC).

DESIGN

Randomized controlled trial.

METHODS

Forty-two male patients with IC (≥50years) were randomly allocated into two groups: control (CG, n=20, 30min of stretching exercises) and WT (WTG, n=22, 15 bouts of 2min of walking interpolated by 2min of upright rest-walking intensity was set at the heart rate of pain threshold). Both interventions were performed twice/week for 12 weeks. Walking capacity (maximal treadmill test), blood pressure (auscultatory), cardiac output (CO₂ rebreathing), heart rate (ECG), stroke volume, systemic vascular resistance, forearm and calf vascular resistance (plethysmography), and low (LF) and high frequency (HF) components of heart rate variability and spontaneous baroreflex sensitivity were measured at baseline and after 12 weeks of the study.

RESULTS

WT increased total walking distance (+302±85m, p=0.001) and spontaneous baroreflex sensitivity (+2.13±1.07ms/mmHg, p=0.02). Additionally, at rest, WT decreased systolic and mean blood pressures (-10±3 and -5±2mmHg, p=0.001 and p=0.01, respectively), cardiac output (-0.37±0.24l/min, p=0.03), heart rate (-4±2bpm, p=0.001), forearm vascular resistance (-8.5±2.8U, p=0.02) and LF/HF (-1.24±0.99, p=0.001). No change was observed in the CG.

CONCLUSIONS

In addition to increasing walking capacity, WT improved cardiovascular function and autonomic regulation in patients with IC.

The effect of supervised exercise therapy for intermittent claudication on lower limb lean mass

OBJECTIVE

Supervised exercise is currently recommended for the first-line treatment of intermittent claudication based on improvement in walking capacity. However, the promotion of skeletal muscle atrophy by repetitive ischemia-reperfusion caused by treadmill-based programs remains a concern. Because preservation of skeletal muscle mass (SMM) and lean mass (LM) is integral to functional capacity and longevity, this study measured the effect of standard treadmill-based supervised exercise on SMM and regional lower limb LM in patients with intermittent claudication.

METHODS

Patients with calf claudication caused by infrainguinal peripheral artery disease underwent whole-body dual-energy X-ray absorptiometry scanning before and after completion of a 12-week supervised treadmill exercise program. Total body SMM and lower limb LM were measured according to anatomical regions of the lower limb (thigh vs calf) and side of symptoms. Walking performance was assessed using pain-free walking distance and 6-minute walking distance tests.

RESULTS

Thirty-six patients with calf claudication completed exercise training and dual-energy X-ray absorptiometry scanning, allowing analysis of 55 symptomatic and 17 asymptomatic lower limbs. No difference in total body SMM (P = .41) or LM of symptomatic (P = .53) or asymptomatic calves (P = .59) was detected after the program. In contrast, a significant decrease in LM was observed in symptomatic (P = .04) and asymptomatic thighs (P = .005). Pain-free walking distance (P = .001) and the 6-minute walking distance both improved significantly (P = .004) but were not associated with changes in LM.

CONCLUSIONS

Twelve weeks of standard treadmill-training for intermittent calf claudication did not result in loss of calf LM; however, a significant decrease in bilateral thigh LM was observed, even in patients with unilateral symptoms. Further research on optimum exercise modalities and end points are required to determine the pathophysiology and effects of these changes on function and survival.

Cost-effectiveness of supervised exercise therapy compared with endovascular revascularization for intermittent claudication

Background

Current guidelines recommend supervised exercise therapy (SET) as the preferred initial treatment for patients with intermittent claudication. The availability of SET programmes is, however, limited and such programmes are often not reimbursed. Evidence for the long-term cost-effectiveness of SET compared with endovascular revascularization (ER) as primary treatment for intermittent claudication might aid widespread adoption in clinical practice.

Methods

A Markov model was constructed to determine the incremental costs, incremental quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio of SETversus ER for a hypothetical cohort of patients with newly diagnosed intermittent claudication, from the Dutch healthcare payer's perspective. In the event of primary treatment failure, possible secondary interventions were repeat ER, open revascularization or major amputation. Data sources for model parameters included original data from two RCTs, as well as evidence from the medical literature. The robustness of the results was tested with probabilistic and one-way sensitivity analysis.

Results

Considering a 5-year time horizon, probabilistic sensitivity analysis revealed that SET was associated with cost savings compared with ER (−€6412, 95 per cent credibility interval (CrI) –€11 874 to –€1939). The mean difference in effectiveness was −0·07 (95 per cent CrI −0·27 to 0·16) QALYs. ER was associated with an additional €91 600 per QALY gained compared with SET. One-way sensitivity analysis indicated more favourable cost-effectiveness for ER in subsets of patients with low quality-of-life scores at baseline.

Conclusion

SET is a more cost-effective primary treatment for intermittent claudication than ER. These results support implementation of supervised exercise programmes in clinical practice.

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.

A Systematic Review of the Uptake and Adherence Rates to Supervised Exercise Programs in Patients with Intermittent Claudication

BACKGROUND

Intermittent claudication (IC) is a common and debilitating symptom of peripheral arterial disease and is associated with a significant reduction in a sufferer's quality of life. Guidelines recommend a supervised exercise program (SEP) as the primary treatment option; however, anecdotally there is a low participation rate for exercise in this group of patients. We undertook a systematic review of the uptake and adherence rates to SEPs for individuals with IC.

METHODS

The MEDLINE, Embase, and PubMed databases were searched up to January 2015 for terms related to supervised exercise in peripheral arterial disease. The review had 3 aims: first, to establish the rates of uptake to SEPs, second, the rates of adherence to programs, and finally to determine the reasons reported for poor uptake and adherence. Separate inclusion and/or exclusion criteria were applied in selecting reports for each aim of the review.

RESULTS

Only 23 of the 53 potentially eligible articles for uptake analysis identified on literature searches reported any details of screened patients (n = 7,517) with only 24.2% of patients subsequently recruited to SEPs. Forty-five percent of screen failures had no reason for exclusion reported. Sixty-seven articles with 4,012 patients were included for analysis of SEP adherence. Overall, 75.1% of patients reportedly completed an SEP; however, only one article defined a minimal attendance required for SEP completion. Overall, 54.1% of incomplete adherence was due to patient withdrawal and no reason for incomplete adherence was reported for 16% of cases.

CONCLUSIONS

Reporting of SEP trials was poor with regard to the numbers of subjects screened and reasons for exclusions. Only approximately 1 in 3 screened IC patients was suitable for and willing to undertake SEP. Levels of adherence to SEPs and definitions of satisfactory adherence were also lacking in most the current literature. Current clinical guidelines based on this evidence base may not be applicable to most IC patients and changes to SEPs may be needed to encourage and/or retain participants.

Attitudes to supervised exercise therapy

Wider acceptance and more facilities needed

Impaired Coronary Endothelial Vasorelaxation in a Preclinical Model of Peripheral Arterial Insufficiency

The present study was designed to determine whether adult swine with peripheral artery insufficiency (PAI) would exhibit vascular dysfunction in vessels distinct from the affected distal limbs, the coronary conduit arteries. Moreover, we sought to evaluate the effect of exercise training on coronary vasomotor function in PAI. Eighteen female healthy young Yucatan miniature swine were randomly assigned to either occluded exercise trained (Occl-Ex, n=7), or occluded-sedentary (Occl-Sed, n=5), or non-occluded, non-exercised control (Non-Occl-Con, n=6) groups. Occl-Ex pigs were progressively trained by running on a treadmill (5days/week, 12 weeks). The left descending artery (LAD) and left circumflex (LCX) coronary arteries were harvested. Vasorelaxation to adenosine diphosphate (ADP), bradykinin (BK), and sodium nitro-prusside (SNP) were assessed in LAD’s; while constrictor responses to phenylephrine (PE), angiotensin II (Ang II), and endothelin-1 (ET-1) were assessed in LCX’s. Vasorelaxation to ADP was reduced in LADs from Occl-Sed and Occl-Ex pigs (P<0.001) as compared to Non-Occl-Con pigs; however, Occl-Ex pigs exhibited partial recovery (P<0.001) intermediate to the other two groups. BK induced relaxation was reduced in LADs from Occl-Ex and Occl-Sed pigs (P<0.001), compared to Non-Occl-Con, and exercise modestly increased responses to BK (P<0.05). In addition, SNP, PE, Ang II, and ET-1 responses were not significantly different among the groups. Our results indicate that ‘simple’ occlusion of the femoral arteries induces vascular dysfunction in conduit vessels distinct from the affected hindlimbs, as evident in blunted coronary vasorelaxation responses to ADP and BK. These findings imply that PAI, even in the absence of frank atherogenic vascular disease, contributes to vascular dysfunction in the coronary arteries that could exacerbate disease outcome in patients with peripheral artery disease. Further, regular daily physical activity partially recovered the deficit observed in the coronary arteries.

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.

Programming exercise intensity in patients on beta-blocker treatment: the importance of choosing an appropriate method

AIM

To verify the usefulness of current recommended level of target exercise heart rate (HR) and of different HR-based methods for calculating target HR in patients with and without beta-blocker treatment.

METHODS

We studied 53 patients not treated with beta-blocker and 159 patients on beta-blocker treatment. All patients underwent a maximal exercise test with gas analysis, and first ventilatory threshold (VT1 or aerobic threshold), second ventilatory threshold (VT2 or anaerobic threshold), time of exercise, maximum load, metabolic parameters, HR at rest (HRrest), HRpeak, HR at VT1 (HRVT1) and at VT2 (HRVT2), and 75, 80, and 85% of HRmax (HR75%, HR80%, HR85%) were calculated. Exercise HR was also determined using the Karvonen formula, applying 60, 70, and 80% of the heart rate reserve (HRR) (HRKarv0.6, HRKarv0.7, and HRKarv0.8).

RESULTS

This study included 102 patients on a beta-blocker and 39 not treated with negative cronotropic effect drugs. Maximum load, metabolic parameters, HRrest, HRpeak, HRVT1, and HRVT2 were significantly lower in patients on beta-blocker treatment. The proportion of patients with a HR75%, HR80%, HR85%, ​​HRKarv0.6, HRKarv0.7, and HRKarv0.8 <VT1 and >VT2 was very high and depended on whether patients were on beta-blocker treatment.

CONCLUSIONS

Prescribed exercise intensity should be within VT1 and VT2, so that the efficacy and safety is guaranteed. If determining VT1 and VT2 is not possible, HR-based methods can be used, but with caution. In fact, there will be always a proportion of patients training below VT1 or above VT2. On the other hand, recommendations for patients on a beta-blocker should be different from patients not receiving a beta-blocker. Patients not treated with a beta-blocker should exercise at HRKarv0.7 or at HR85%. In patients on a beta-blocker, we recommend preferentially a target HR of HRKarv0.6 or HR80%.

Arterial stiffness and walk time in patients with end-stage renal disease

BACKGROUND

End-stage renal disease patients experience increased prevalence of cardiovascular disease. Heart-artery interaction may be shifted, impacting blood pressure lability, and exercise tolerance. The coupling ratio consists of the ratio of indexed arterial elastance (EaI, arterial load) to ElvI, a measure of cardiac contractility or stiffness. Our purpose was to explore the relationship between elastances and functional capacity. We hypothesized that arterial stiffness (central pulse wave velocity, PWV) and elastances would be correlated to shuttle walk time.

METHODS

We used applanation tonometry, ultrasonography, and a shuttle walk test to evaluate our hypothesis. Spearman's correlations were used to assess relationships between variables. Block regression was also performed.

RESULTS

Forty-two subjects on maintenance hemodialysis participated. Average age=44±5 years, body surface area=2.01 kg/m(2). Mean EaI=4.45 and mean ElvI=6.89; the coupling ratio=0.82. Mean aortic pulse pressure=51 mmHg and PWV=9.6 m/s. PWV(r=-0.385) and EaI (r=-0.424) were significantly and inversely related to walking time while stroke volume index (SVI) was positively correlated to shuttle walk time (r=0.337), p<0.05 for all.

CONCLUSIONS

We conclude that, like other clinical populations, both arterial and heart function predict walking ability and represent potential targets for intervention; arterial stiffness and SVI are strongly related to shuttle walk time in patients with ESRD.

Importance of the ankle-brachial pressure index in the diagnosis of coronary artery disease in women with diabetes without anginal pain

BACKGROUND

Clinical symptoms of coronary artery disease (CAD) are often atypical in women, particularly in those with diabetes mellitus. Therefore, a simple diagnostic test to identify a high-risk subset of women with diabetes who are likely to have CAD is important.

METHODS AND RESULTS

A total of 407 consecutive patients (319 men and 88 women, age range 68 ± 11 years) with suspected CAD, who were not complaining of anginal pain, were evaluated. Among these patients, 170 had diabetes. Stress myocardial perfusion imaging and simultaneous brachial and ankle blood pressure measurements were performed to obtain the ischemic total perfusion deficit (TPD) and ankle-brachial pressure index (ABI), respectively. Ischemic TPD was not significantly different between men and women, whereas ischemic TPD was significantly greater in diabetic patients than in non-diabetic patients (6.9 ± 7.7% vs. 4.9 ± 6.1%; P = 0.005). In diabetic patients, ischemic TPD was not significantly different between men and women. However, women with ABI<0.9 showed significantly greater ischemic TPD than those with ABI≥0.9 (12.1 ± 10.8% vs. 5.1 ± 5.9%; P=0.04), whereas no difference in ABI was observed in men.

CONCLUSIONS

ABI was useful in evaluating CAD in asymptomatic women with diabetes to detect a high-risk subset showing the ischemic TPD of >10%, which is regarded as a scintigraphic indicator for coronary revascularization.