Motivating Physical Activity With Behavioural interVention and Electrical Stimulation Remotely in Intermittent Claudication

Peripheral Arterial Disease (PAD) is a common vascular disease which is symptomatic in 2.4% of 50 to 89 year olds in the UK population. Symptomatic PAD initially presents clinically as limb pain and reduced exercise intolerance termed Intermittent Claudication (IC). Patients with PAD and IC have impaired quality of life due to reduced physical capacity and 3-4 times increased mortality compared to age and sex matched controls.

Improving daily physical activity (PA) is particularly important in individuals with IC as lower PA levels have been recognised as a strong predictor of increased morbidity and mortality in this population. Supervised exercise programs are recommended in clinical guidelines with proven efficacy to help increase physical activity, improve quality of life and contribute to secondary prevention of adverse cardiovascular events (ACVE). Despite this, provision of classes is varied geographically in the UK, and generally is centralised away from rural areas, which may limit uptake and adherence. An alternative to this exercise format may be home-based exercise in the format of a walking-based behaviour change intervention. Home-based exercise for people with intermittent claudication demonstrate a low number of related adverse events, and in the case of walking-based programmes, are likely more accessible, require little equipment, and involve increasing an activity of daily living (ADL) in people with intermittent claudication. Therefore, there is a need for investigation to the acceptability of novel methods of increasing physical activity in a home-based setting.

Lack of self-efficacy, attributed to poor understanding of the disease and uncertainty regarding the importance of exercise, has been shown to be a major barrier to exercise uptake in patients with PAD and IC. Moreover, home based exercise for the self-management of IC is less established in the literature than SEP and there are concerns of low adherence without clinician monitoring. However, if an engaging intervention feasible to the patient and healthcare provider can be established there is potential for greater equality in care, reduced healthcare utilisation and improvement of self-management of PAD in the population.

A proposed intervention to augment walking based physical activity is Transcutaneous electrical nerve stimulation (TENS). TENS a low-cost, non-invasive pain management device with aims to improve pain and walking distances in patients with IC. In our exploratory study we demonstrated that TENS applied to the lower limb during treadmill walking significantly improved pain and increased treadmill walking distances above placebo levels. In addition, Motivating Structured Walking Activity in People with Intermittent Claudication (MOSAIC) is a walking based behavioural intervention utilising motivational interviewing to help people with PAD and IC increase their physical activity. This may help patients plan and overcome barriers to increasing their physical activity by joint clinician and patient set physical activity goals. Both TENS and MOSAIC have potential for remote delivery which could have effects on secondary prevention of ACVE alongside improved function and quality of life for this high-risk group, and ensuring that patients can continue to undertake exercise where it is not feasible to attend SEP, or where fluctuations in social-distancing restrictions occur.

Although TENS and behavioural interventions have been utilised previously in this population to improve physical activity. Neither MOSAIC or TENS have been utilised with aim to improve free living physical activity measured using an accelerometer, and there is a lack of data investigating these outcomes with home based exercise in general. While the author is aware of ongoing works investigating these outcomes, no trial to date has been developed a priori to evaluate the delivery of these treatments remotely in this population.

The primary aim of MAvERIC is to determine the acceptability and feasibility of electrical stimulation via a low-cost CE-marked device, and a remotely delivered walking based behavioural intervention (MOSAIC) in patients with PAD, compared to usual care.

The following research questions will be answered by this project:

1. What is the feasibility (i.e. recruitment and retention rates, adherence, safety, sample size for a definitive trial, potential for effectiveness) of conducting a definitive RCT utilising TENS or MOSAIC as an intervention compared to usual care?
2. How acceptable is TENS and MOSAIC interventions to patients with IC?
3. What are the effects of TENS and MOSAIC as interventions on free living physical activity, pain related, and quality of life PROMs?