Transcutaneous Electrical Nerve Stimulation Improves Walking Performance in Patients With Intermittent Claudication

A Multicenter, Investigator-Blinded, Randomized Controlled Trial to Assess the Efficacy of Calf Neuromuscular Electrical Stimulation Program on Walking Performance in Peripheral Artery Disease: The ELECTRO-PAD Study Protocol

This paper describes a currently on-going multicenter, randomized controlled trial designed to assess the efficacy of calf neuromuscular electrical stimulation (NMES) on changes in maximal walking distance in people with lower extremity peripheral artery disease (PAD), compared with a non-intervention control-group. This study (NCT03795103) encompasses five participating centers in France. PAD participants with a predominant claudication at the calf level and a maximal treadmill walking distance ≤300 m are randomized into one of the two groups: NMES group or Control group. The NMES program consists of a 12-week program of electrical stimulations at the calf-muscle level. The primary outcome of the study is the change in maximal treadmill walking distance at 12 weeks. Main secondary outcomes include changes in the pain-free treadmill walking distance; 6 min total walking distance; global positioning system (GPS)-measured outdoor walking capacity; daily physical activity level by accelerometry; self-reported walking impairment; self-reported quality of life; ankle-brachial index; and skin microvascular function, both at the forearm and calf levels. Recruitment started in September 2019 and data collection is expected to end in November 2022.

Transcutaneous Electric Nerve Stimulation on ischemic rest pain in inpatients: randomised trial

OBJECTIVE

To investigate the efficacy of a short-term application of Transcutaneous Electric Nerve Stimulation to relieve rest pain in patients with chronic limb-threatening ischemia.

METHODS

In patients ³18 years old, with chronic limb-threatening ischemia and rest pain ³3 in the Visual Analogue Scale, without diabetic neuropathy were randomly assigned to 1) Transcutaneous Electric Nerve Stimulation (100 Hz, 200 μs) or 2) sham intervention, both during one or two 20 min treatment sessions. The primary outcome was pain intensity, assessed by the visual analogue scale (0-10 cm) and described by the McGill Pain Questionnaire. We used a t-test for difference of means.

RESULTS

A total of 169 patients were assessed, 23 met the study criteria and were randomized. Thirty-four applications were performed in two days: in the 17 Transcutaneous Nerve Stimulation and 17 sham. The within-group analysis indicated a pain decrease in both groups (Transcutaneous Electric Nerve Stimulation, from 7-3.9 cm, p<0.0001, and sham from 5.8-3.2 cm, p<0.0001). No statistically significant difference was verified between-groups (p=0.5).

CONCLUSIONS

Both groups showed a decrease in rest pain of 54 and 55%, respectively. However, there was no difference between short-term high-frequency Transcutaneous Electric Nerve Stimulation and sham intervention to relieve ischemic rest pain in chronic limb-threatening ischemia patients.

Challenges in recruitment and adherence to a randomized clinical trial in Brazil on the effects of transcutaneous nervous electrical stimulation on individuals with peripheral arterial disease: A feasibility study

OBJECTIVE

Describe the feasibility, barriers during the recruitment and intervention period, recruitment rate (success and efficiency), and the level of participation and adherence in the randomized clinical trial to verify the effects of transcutaneous electrical nerve stimulation (TENS) for the symptoms of intermittent claudication (IC) and its repercussions on functional capacity, cardiorespiratory fitness and cardiovascular autonomic function in individuals with sta II Fontaine classification, residing in Brazil.

DESIGN

Prospective, double-blind, randomized clinical trial.

SETTING

Level secondary.

PARTICIPANTS

A total of 63 participants were screened, of which 12.6% were included. Eight individuals with peripheral arterial disease (PAD) and IC underwent a protocol that lasted 8 weeks.

INTERVENTIONS

The experimental group received 45 minutes TENS 10 Hz, followed by 30 minutes of aerobic exercise, and the control group received a placebo TENS also followed by 30 minutes of exercise. Incremental walking test, gait impairment questionnaire, treadmill test, heart rate variability, and 4-second test were applied, considering adherence, success, and efficiency.

RESULTS

The most efficient recruitment sources were as follows: 1) referral by physician and 2) referral by a physiotherapist. Out of 63 participants, 8 (12.6%) were included in the clinical trial. Participants were excluded due to the following reasons: not meeting the criteria (41 participants (65%)), locomotion (6 participants (9.5%)), transportation (5 participants (7.9%)), work release (1 participant (1.6%)), and interest (2 participants (3.2%)). The overall participation was 99 participants (51.6%) in a total of 192 sessions offered.

CONCLUSION

It was not possible to succeed in recruitment and adherence rates. The results of this clinical trial reinforce that PAD is neglected, and strategies including a multidisciplinary approach with the effective participation of nursing, physiotherapy, medicine, and nutrition professionals, are necessary to optimize care for individuals with PAD need to be strengthened. Brazilian Registry of Clinical Trials (RBR-8RTZFN).

A systematic review of lower extremity electrical stimulation for treatment of walking impairment in peripheral artery disease

Lower extremity peripheral artery disease (PAD) induces an ischemic pain in the lower limbs and leads to walking impairment. Electrical stimulation has been used in patients with PAD, but no systematic review has been proposed to address the efficacy of the technique as a treatment for walking impairment in PAD. A systematic search was performed to identify trials focused on electrical stimulation for the treatment of walking impairment in patients with PAD in the Cochrane Central Register, PubMed, Embase, and the Web of Science. Studies were included where the primary outcomes were pain-free walking distance and/or maximal walking distance. When appropriate, eligible studies were independently assessed for quality using the Cochrane Collaboration's tool for assessing risk of bias. Five studies eligible for inclusion were identified, of which only two were randomized controlled studies. Trial heterogeneity prevented the use of the GRADE system and the implementation of a meta-analysis. Three types of electrical stimulation have been used: neuromuscular electrical stimulation (NMES, n = 3), transcutaneous electrical stimulation (n = 1), and functional electrical stimulation (n = 1). The two available randomized controlled studies reported a significant improvement in maximal walking distance (+40 m/+34% and +39 m/+35%, respectively) following a program of NMES. Owing to the low number of eligible studies, small sample size, and the risk of bias, no clear clinical indication can be drawn regarding the efficacy of electrical stimulation for the management of impaired walking function in patients with PAD. Future high-quality studies are required to define objectively the effect of electrical stimulation on walking capacity.

Using wearable monitors to assess daily walking limitations induced by ischemic pain in peripheral artery disease

PURPOSE

To develop, assess the feasibility of, and determine the clinical validity of an event-based analysis method using wearable monitors to quantify walking pain manifestations (WPMs) and stops induced by walking pain (SIWPs) during daily life walking in people with peripheral artery disease (PAD).

METHODS

The following two conditions were studied: a standardized outdoor walking session (OWS) and a seven-day free-living measurement (FLM) period. The PAD participants (n = 23) wore an accelerometer and a watch. They were asked to press the event marker button on the watch to indicate events related to WPMs and SIWPs. To assess the clinical validity of the method, the computed pain-free walking time (PFWT) and maximal walking time (MWT) were compared with the PFWT and MWT assessed using standard treadmill walking protocols, respectively.

RESULTS

Following OWSs, the PFWT^[OWS] and MWT^[OWS] were significantly correlated with the PFWT^[Strandness] (r = .955, P < .001) and MWT^[Strandness] (r = .821, P < .001), respectively. During the FLM, PAD participants experienced only 2 WPMs/day and 1 SIWP/day, although severely limited on the treadmill and during the OWS. The average WPMs/day were moderately correlated with the PFWT^[Strandness] (r = -.54, P = .016). The PFWT^[FLM] was on average 12 times longer than the PFWT^[Strandness] . Interestingly, the intensity of the walking bouts as assessed by the accelerometer counts during the FLM was significantly lower than that during the OWS (45 ± 15 vs 66 ± 20 counts/s, P < .001).

CONCLUSION

This new method offers opportunities for studies investigating the experience of living with PAD and the assessment of daily life walking capacity for both diagnostic and therapeutic purposes.

Efficacy and Feasibility of Pain management and Patient Education for Physical Activity in Intermittent claudication (PrEPAID): protocol for a randomised controlled trial

Background

Physical activity (PA) improves functional capacity and quality of life and provides secondary prevention benefits in individuals with peripheral arterial disease (PAD) and intermittent claudication (IC). However, pain and patient lack of knowledge are key barriers to the uptake of, and adherence to, PA recommendations. This trial will test the efficacy and feasibility of a non-invasive pain management intervention with and without patient education to improve PA in individuals with PAD and IC.

Methods

This is a randomised, controlled assessor-blinded feasibility trial with four parallel groups. Eighty adults with PAD and IC will be randomly assigned 1:1:1:1 to Active TENS (transcutaneous electrical nerve stimulation), Placebo TENS, Active TENS + Patient education or Placebo TENS + Patient education groups. All groups will continue to receive usual care over the intervention period. Participants randomised to Active TENS will receive a TENS device (preset at 120 Hz, 200 μs) and will be instructed to use the device daily at home or elsewhere for 6 weeks with a patient-determined intensity of “strong but comfortable”. Placebo TENS group participants will receive the same model of TENS device and instructions for use as those in the active group, except that the stimulation dose will be safely altered to produce non-therapeutic, ineffective stimulation. Participants randomised to patient education will receive a one-off 3-h workshop of structured group education (four to five persons in each group) and three sets of twice-weekly phone calls. Efficacy outcomes will be assessed at baseline, after 6 weeks of intervention and at 3 months follow-up. Absolute claudication distance using the Gardner treadmill protocol will be assessed as the primary outcome. Secondary outcomes will assess initial claudication distance, daily PA and patient-reported outcomes including quality of life, pain self-efficacy, depression, disease perception and walking impairment pain intensity and quality. Feasibility outcomes will assess rates of recruitment, retention and adherence. Focus groups with participants at the end of the trial will explore the acceptability of the interventions.

Discussion

This trial will determine the efficacy and feasibility of using a low-cost, CE-marked non-invasive pain management modality delivered with or without a patient-centred education intervention to improve PA in individuals with PAD and IC.

Trial registration

ClinicalTrials.gov, NCT03204825. Registered on 2 July 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3307-6) contains supplementary material, which is available to authorized users.

A systematic review of muscle morphology and function in intermittent claudication

OBJECTIVE

Intermittent claudication (IC) is frequently associated with deterioration in walking capacity and physical function, and it can often result in an impairment in balance. Whereas supervised exercise is recommended by the National Institute for Health and Care Excellence as the first-line treatment, the mechanism behind walking improvement is poorly understood. The existing literature suggests that there may be some physiologic change to the skeletal muscle contributing to the functional impairment, but these data are conflicting. We therefore sought to undertake a systematic review to clarify the muscle properties of patients with IC.

METHODS

A systematic review of randomized and nonrandomized trials that investigated the role of muscle function in patients diagnosed with IC was undertaken using MEDLINE, Cochrane Central Register of Controlled Trials, and Embase databases. The searches were limited from 1947 to June 2016 in the English language.

RESULTS

The search yielded a total of 506 articles, of which 206 were duplicate articles. Of the remaining 300, a total of 201 were excluded from full-text analysis; 99 full-text articles were assessed for eligibility, with 30 articles deemed appropriate for inclusion in the review. There were four main categories of functional outcome measures: muscle strength, muscle size, muscle fiber type, and muscle metabolism. A total of 2837 patients were included in the study. Nine studies reported on muscle strength, incorporating isometric, concentric, eccentric, and endurance measures. Eight studies reported on muscle size, incorporating circumference, computed tomography scans, and ultrasound imaging techniques. Eleven studies reported on muscle fibers, incorporating fiber type proportions, fiber size, and capillarity measures. Seven papers reported on muscle metabolism, incorporating adenosine diphosphate recovery and phosphocreatine recovery measures.

CONCLUSIONS

Previous literature has found clear evidence that strength (of the calf and thigh musculature) and calf characteristics are related to mortality and functional declines. However, this review has demonstrated the vast array of muscle groups assessed and multiple methods employed to determine strength; therefore, it is unclear exactly what measure of "strength" is impaired. Furthermore, the underlying morphologic causes of potential changes in strength are unclear. This information is essential for designing optimal exercise interventions. The data acquired during this systematic review are heterogeneous, with a substantial lack of high-quality intervention-based studies. Future research should endeavor to establish standardized testing procedures and to implement randomized controlled trials for targeted therapeutic interventions.