Title: High Intensity Interval Training In pATiEnts with intermittent claudication (INITIATE): a proof-of-concept prospective cohort study to assess acceptability, feasibility and potential clinical efficacy
Funder: Department of Health and Social Care

Abstract: Background; NICE guidelines recommend first line treatment for patients with intermittent claudication is a supervised exercise programme. These programmes are unpopular with patients with only a 24% uptake in the UK. Time constraints are cited as the most common reason for non participation. In other clinical populations (e.g. coronary artery disease patients), High Intensity Interval Training (HIIT) is clinically superior and more time efficient than other types of exercise programmes. Aims; to assess the utility, safety, acceptability, and potential clinical effectiveness of a HIIT programme in patients with intermittent claudication. Design; a 2 centre, mixed methods, prospective, &quot;proof of concept&quot; cohort study. Setting; 2 academic vascular surgical units in secondary care NHS trusts Population; consenting adults with IC, able to comply with exercise instructions will be eligible. Patients unable to provide informed consent, with significant comorbidities precluding HIIT, or uncontrolled hypertension will be excluded. Intervention to be assessed; patients will be enrolled on a supervised, bicycle HIIT programme, standardised across both units. The HIIT programme consists of 3 exercise sessions per week for six weeks. Each exercise session involves 10 sets of 1 minute high intensity exercise interspersed with 1 minute low intensity exercise, thus each session lasts 20 minutes. Exercise intensity will be set at 85-90% peak power output during high intensity and 20-25% during low intensity, assessed using heart rate. Tapered introduction to the HIIT programme with fewer exercise sets in the first 2 weeks will be used if required. Outcomes; a) Utility; will include eligibility, recruitment, adherence and tolerability rates. b) Acceptability will be assessed using qualitative methods (questionnaires and semi-structured interviews) b) Safety outcomes; will include adverse events and serious adverse events c) Clinical outcomes will be assessed before commencing and after completion of the HIIT programme and will include; - Pain Free Walking Distance and Maximum Walking Distance using the Gardner graded treadmill test - Ankle Brachial Pressure Index at rest and following treadmill testing - Quality of life using generic (SF36) and disease specific (VascuQoL) instruments - Cardiorespiratory fitness using a standardised ramped cycle cardiopulmonary exercise test (CPET) Sample Size; as this is a proof of concept study, there is no formal sample size calculation. We aim to recruit 20 patients from each of the 2 sites over 12 months (40 patients in total), with at least 20 patients contributing to the acceptability qualitative study. Project Timetable; total project duration 24 months, including set up (0-6 months), recruitment & qualitative study(6-18months), completion of follow up (18-21 months), analysis and reporting (21-24 months) Project team; this project brings together world leading, experienced, expert clinicians, trialists, exercise scientist and methodologists with specific research interests in the non invasive management of intermittent claudication and high intensity interval training programmes. Impact; this study has the potential to rapidly influence international guidelines regarding the delivery of exercise programmes for patients with intermittent claudication. Dissemination; presentation at (inter)national meetings, publication in prestigious journals, local & national press release, lay summaries for patient groups and patient facing / charity websites.

Lay abstract: Background: Arterial disease in the legs is a common condition affecting 5-10% of the population over 60 years old. Fatty deposits build up in the arteries restricting blood supply to leg muscles, causing pain when walking which severely limits walking ability and quality of life. The medical term for this is &ldquo;intermittent claudication&rdquo; (IC). Clinical trials have shown that supervised exercise programmes significantly improve patients' symptoms, walking distances and quality of life. The NHS and the National Institute of Health and Care Excellence recommend these exercise programmes (at least 2 hours per week for 3 months) as first line treatment for intermittent claudication. However, although we know exercise programmes work, they are not popular with patients. Only 24% of patients who are offered exercise therapy will actually start the programme. The most common reason patients cite for declining is that the programmes are too time consuming Recent research, mainly in heart disease patients, suggests a new type of &quot;high intensity&quot; exercise programme, may be just as effective but more appealing to patients, potentially increasing the number of patients taking up exercise programmes. This is because &quot;high intensity&quot; programmes have both shorter exercise class times (20 minutes) and total programme duration (6 weeks). &quot;High intensity&quot; exercise involves alternating repeated short bursts of hard exercise with easy exercise or recovery. Aims: This study will assess whether &quot;high intensity&quot; exercise programmes in patients with claudication are - safe and well tolerated - effective in improving symptoms, fitness and quality of life - are appealing and improve uptake rates Design: Forty patients with intermittent claudication will undertake a 20 minute &quot;high intensity&quot; exercise session, 3 times / week, for 6 weeks, using a static bicycle at the 2 NHS hospitals. We will measure - adverse effects of the programme, how easy or hard patients find the exercise programme, and whether patients can achieve the intended exercise intensity by measuring heart rate - effectiveness of the programme using treadmill walking tests and questionnaires assessing patients' symptoms and general health related quality of life, before and after the &quot;high intensity&quot; programme - the appeal of the &quot;high intensity&quot; programme using uptake / completion rates and patient views and opinions at interview Patient & Public involvement; Our PPI group &ldquo;Humberside Peripheral Arterial Research Involvement Group&rdquo; was fundamental in identifying the original research question and development of the study design. They remain committed to supporting future study delivery and dissemination. Impact & dissemination; this study will determine whether further research into &quot;high intensity&quot; exercise programmes in patients with claudication is feasible and worthwhile. Study results will be; presented at prestigious (inter)national meetings, published in medical journals, distributed to participants as a lay summary

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS;6.7 PHYSICAL
Health categories: CARDIOVASCULAR