Extracorporeal Shockwave for Intermittent Claudication and Quality of Life: A Randomized Clinical Trial

Importance

Intermittent lower limb claudication limits function and quality of life. Supervised exercise programs are not readily available, and a noninvasive alternative is needed.

Objective

To assess extracorporeal corporeal shockwave therapy in improving quality of life in patients with claudication.

Design, Setting, and Participants

In this double-blind, placebo-controlled randomized clinical trial, patients in the outpatient setting at a single tertiary center for vascular surgery were randomized in a 1:1 ratio to extracorporeal shockwave therapy or placebo therapy with no shockwaves delivered. Recruitment was between June 2015 and January 2020, with 12-week follow-up ending in March 2020. A convenience sample of patients with claudication and conservative treatment requirements who refused or were unable to participate in supervised exercise were eligible. Patients receiving anticoagulation therapy or with an active cancer were excluded. Of 522 patients screened, 389 were eligible, 138 were enrolled, and 110 completed follow-up and were included in the primary analysis. Statistical analysis was completed by May 2021.

Intervention

In the intervention group, patients received 100 impulses of 0.1mJ/mm/cm2 in an area of the gastrocnemius muscle 3 times weekly for 3 weeks. The steps for treatment were replicated for the control group without delivering the treatment.

Main Outcomes and Measures

The primary outcome was the Physical Functioning domain of the 36-item Short-Form Quality of Life Questionnaire at 12-week follow-up. Secondary outcomes included walking distances, ankle brachial pressure index, and other quality-of-life measures.

Results

Of 138 patients recruited and randomized, 92 (67%) were male, and the mean (SD) age of the study population was 67 (9.6) years. The intervention group had a significantly higher physical function score at 12 weeks (estimated median difference 3.8; 95% CI, 0.0-7.7; P = .03). However, this significance did not remain when adjusting for covariates. At 12 weeks, the intervention group had significantly longer pain-free and maximum walking distances (pain-free estimated median difference, 34.1, 95% CI, 11.4-56.8; P = .004; maximum estimated median difference, 51.4; 95% CI, 10.7-86.5; P = .01).

Conclusions and Relevance

To our knowledge, this is the first double-blind, placebo-controlled, randomized clinical trial to consider extracorporeal shockwave therapy for the management of intermittent claudication. It demonstrated efficacy for walking distances, may have a positive effect on quality of life, and may provide a safe, noninvasive alternative therapy for patients with intermittent claudication.

Trial Registration

ClinicalTrials.gov Identifier: NCT02652078.

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.

High-intensity interval training in patients with intermittent claudication

OBJECTIVE

Provision, uptake, adherence, and completion rates for supervised exercise programs (SEP) for intermittent claudication (IC) are low. A shorter, more time-efficient, 6-week, high-intensity interval training (HIIT) program may be an effective alternative that is more acceptable to patients and easier to deliver. The aim of this study was to determine the feasibility of HIIT for patients with IC.

METHODS

A single arm proof-of-concept study, performed in secondary care, recruiting patients with IC referred to usual-care SEPs. Supervised HIIT was performed three times per week for 6 weeks. The primary outcome was feasibility and tolerability. Potential efficacy and potential safety were considered, and an integrated qualitative study was undertaken to consider acceptability.

RESULTS

A total of 280 patients were screened: 165 (59%) were eligible, and 40 (25%) were recruited. The majority (n = 31; 78%) of participants completed the HIIT program. The remaining nine patients were withdrawn or chose to withdraw. Completers attended 99% of training sessions, completed 85% of sessions in full, and performed 84% of completed intervals at the required intensity. There were no related serious adverse events. Maximum walking distance (+94 m; 95% confidence interval, 66.6-120.8 m) and the SF-36 physical component summary (+2.2; 95% confidence interval, 0.3-4.1) were improved following completion of the program.

CONCLUSIONS

Uptake to HIIT was comparable to SEPs in patients with IC, but completion rates were higher. HIIT appears feasible, tolerable, and potentially safe and beneficial for patients with IC. It may provide a more readily deliverable, acceptable form of SEP. Research comparing HIIT with usual-care SEPs appears warranted.

O080 A double-blind, placebo-controlled, randomised trial of extracorporeal shockwave therapy as a novel treatment for intermittent claudication

Introduction

Intermittent claudication (IC) is a prevalent manifestation of peripheral arterial disease and affects about 3% of the UK population. Current guidance for the management of nonlife limiting IC is supervised exercise and best medical therapy. Supervised exercise however is not readily available across the nation and has poor recruitment and retention rates. Pilot data has demonstrated that Extracorporeal ShockWave Therapy (ESWT) is effective for improving walking distance in patients with IC. This study aims to consider its effectiveness for improving quality of life (QoL).

Methods

In a double-blind, sham-controlled, randomised trial, patients with IC were randomised in a 1:1 ratio to ESWT or sham treatment. The primary endpoint was change in physical functioning at 12-week follow-up, as measured by the SF-36. Secondary endpoints included changes in walking distances and ABPI.

Results

138 patients were randomised. The ESWT group had a significantly higher physical functioning score at 12 weeks (Mdn 41 vs 34, z=-2.1, p=0.033). They also had significantly longer claudication (Mdn 125 vs 88, z=-2.9, p=0.004) and maximum (Mdn 179 vs 129, z=-2.4, p=0.013) walking distances. The change from baseline to 12-weeks was also significantly greater in the ESWT group for claudication (Mdn 51 vs 24, z=-2.8, p<0.01) and maximum (Mdn 63 vs 17, z=-4 p<0.01) walking distance. No difference observed in ABPI.

Conclusion

This study demonstrates that ESWT is safe, well tolerated and clinically effective for improving QoL and walking distances in patients with IC.

Take-home message

Extracorporeal shockwave therapy improves quality of life and walking distances, and could potentially be used as a non-invasive adjunct to supervised exercise or in institutions were supervised exercise is not available.

SPOD.01A double-blind, placebo-controlled, randomised trial of extracorporeal shockwave therapy as a novel treatment for intermittent claudication

Aims

Intermittent claudication (IC) is a prevalent manifestation of peripheral arterial disease. Pilot data has shown Extracorporeal ShockWave Therapy (ESWT) as a novel, non-invasive treatment for IC. We aim to compare the effects of ESWT on quality of life (QoL) and walking distances of patients with lower limb IC through a randomised trial.

Methods

A double-blind, placebo-controlled, randomised trial, where patients with lower limb IC were randomised at a 1:1 ratio to ESWT or placebo. Primary outcome was the physical functioning domain of the SF-36 QoL questionnaire at 12-week follow up. Secondary outcomes included claudication and maximum walking distances, and Ankle Brachial Pressure Index (ABPI).

Results

Full study power achieved with 138 patients randomised. The ESWT group had a significantly higher physical function score at 12 weeks (Mdn 41 vs 34, z=-2.1, p = 0.033). At 12 weeks the ESWT group had significantly longer claudication and maximum walking distances (Claudication Mdn 125 vs 88, z=-2.9, p = 0.004) (Maximum Mdn 179 vs 129, z=-2.4, p = 0.013). The increase in claudication and maximum walking distance at 12 weeks from baseline was also significantly higher in the ESWT group (Mdn 51 vs 24, z=-2.8, p < 0.01) (Mdn 63 vs 17, z=-4 p < 0.01).

Conclusion

This study demonstrates ESWT is clinically effective in improving QoL and walking distances in patients with lower limb IC.

Provision of exercise services in patients with peripheral artery disease in the United Kingdom

Objectives

Supervised exercise programmes (SEPs) are a vital treatment for people with intermittent claudication, leading improvements in walking distance and quality of life and are recommended in multiple national and international guidelines. We aimed to evaluate the use and structure of SEPs in the United Kingdom (UK).

Design

We conducted an anonymous online survey using the Jisc platform comprising of 40 questions. The survey was designed to address key areas such as access, provision, uptake and delivery of SEPs in the United Kingdom. Ethical approval was obtained from Coventry University (P108729).

Methods

The list of trusts providing vascular services was obtained from the National Vascular Registry (NVR) report. The survey was disseminated via social media, The Vascular Society of Great Britain and Ireland and the Society for Vascular Technology. Data were exported to a Microsoft Excel document and analysed using simple descriptive statistics.

Results

Of 93 vascular units identified, we received response from 48. Of these, 23 had access to an exercise programme (48%). The majority of SEPs were exclusively for PAD patients (77%), with 21% using integrated services. 67% of respondents were providing a circuit-based programme, and 5 out of 23 were meeting the dose recommendations in the UK National Institute for Health and Care Excellence (NICE) guidelines. Respondents felt that programmes were moderately to extremely important to patients, slightly to very important to clinicians and not at all important to slightly important to commissioning/funding bodies.

Conclusion

SEPs are a well-established first-line treatment for patients with IC and they are recommended by NICE guidelines. Despite this, many patients still do not have access to an exercise programme, and clinicians do not feel that they have support from commissioning/funding bodies to develop them. There is an urgent need for funding, development and delivery of SEPs in the United Kingdom.

Feasibility and reproducibility of a cardiovascular magnetic resonance free-breathing, multi-shot, navigated image acquisition technique for ventricular volume quantification during continuous exercise

Background

Cardiovascular magnetic resonance (CMR) image acquisition techniques during exercise typically requires either transient cessation of exercise or complex post-processing, potentially compromising clinical utility. We evaluated the feasibility and reproducibility of a navigated image acquisition method for ventricular volumes assessment during continuous physical exercise.

Methods

Ten healthy volunteers underwent supine cycle ergometer (Lode) exercise CMR on two separate occasions using a free-breathing, multi-shot, navigated, balanced steady-state free precession cine pulse sequence. Images were acquired at 3-stages, baseline and during steady-state exercise at 55% and 75% maximal heart rate (HR_max), based on a prior supine cardiopulmonary exercise test. Intra-and inter-observer variability and inter-scan reproducibility were derived. Clinical feasibility was tested in a separate cohort of patients with severe mitral regurgitation (n=6).

Results

End-diastolic volume (EDV) of both LV and RV decreased during exercise at 55% and 75% HR_max, although a reduction in RVEDV index was only observed at 75% HR_max. Ejection fractions (EF) for both ventricles were significantly higher at 75% HR_max compared to their respective baselines (LVEF 68%±3% vs. 58%±5%, P=0.001; RVEF 66%±4% vs. 58%±7%, P=0.02). Intra-observer and inter-observer reproducibility of LV parameters was excellent at all 3-stages. Although measurements of RVESV were more variable during exercise, the reproducibility of both RVEF and RV cardiac index was excellent (CV <10%). Inter-scan LV and RV ejection fraction were highly reproducible at all 3 stages, although inter-scan reproducibility of indexed RVESV was only moderate. The protocol was well tolerated by all patients.

Conclusions

Exercise CMR using a free-breathing, multi-shot, navigated cine imaging method allows simultaneous assessment of left and right ventricular volumes during continuous exercise. Intra- and inter-observer reproducibility were excellent. Inter-scan LV and RV ejection fraction were also highly reproducible.

High INtensity Interval Training In pATiEnts with intermittent claudication (INITIATE): protocol for a multicentre, proof-of-concept, prospective interventional study

INTRODUCTION

The first-line recommended treatment for patients with intermittent claudication (IC) is a supervised exercise programme (SEP), which includes a minimum of 2-hours of exercise per week over a 12-week period. However, provision, uptake and adherence rates for these SEP programmes are poor, with time constraints cited as a common participant barrier. High-intensity interval training (HIIT) is more time-efficient and therefore has the potential to overcome this barrier. However, evidence is lacking for the role of HIIT in those with IC. This proof-of-concept study aims to consider the safety, feasibility, tolerability and acceptability of a HIIT programme for patients with IC.

METHODS AND ANALYSIS

This multicentre, single-group, prospective, interventional feasibility study will recruit 40 patients with IC, who will complete 6 weeks of HIIT, 3 times a week. HIIT will involve a supervised programme of 10×1 min high-intensity cycling intervals at 85%-90% peak power output (PPO), interspaced with 10×1 min low intensity intervals at 20%-25% PPO. PPO will be determined from a baseline cardiopulmonary exercise test (CPET) and it is intended that patients will achieve ≥85% of maximum heart rate from CPET, by the end of the second HIIT interval. Primary outcome measures are safety (occurrence of adverse events directly related to the study), programme feasibility (including participant eligibility, recruitment and completion rates) and HIIT tolerability (ability to achieve and maintain the required intensity). Secondary outcomes include patient acceptability, walking distance, CPET cardiorespiratory fitness measures and quality of life outcomes.

ETHICS AND DISSEMINATION

Ethical approval was obtained via a local National Health Service research ethics committee (Bradford Leeds - 18/YH/0112) and recruitment began in August 2019 and will be completed in October 2020. Results will be published in peer-reviewed journals and presented at international conferences and are expected to inform a future pilot randomised controlled trial of HIIT versus usual-care SEPs.

TRIAL REGISTRATION NUMBER

NCT04042311; Pre-results.