Home-based blood flow restriction exercise in people with peripheral arterial disease
| ISRCTN | ISRCTN12347290 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN12347290 |
| Integrated Research Application System (IRAS) | 359782 |
| Central Portfolio Management System (CPMS) | 69032 |
| National Institute for Health and Care Research (NIHR) | 209640 |
| Sponsor | Sheffield Health Partnership University NHS Foundation Trust |
| Funder | National Institute for Health and Care Research |
- Submission date
- 16/06/2026
- Registration date
- 18/06/2026
- Last edited
- 18/06/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Peripheral artery disease (PAD) is a common condition where narrowed arteries reduce blood flow to your limbs (usually the legs). According to treatment guidelines, patient care should include advice and treatment aimed at prevention of cardiovascular disease with referral to a supervised exercise training (SET) programme. However, SET programmes are affected by low availability and adherence.
Blood flow restriction exercise (BFR), where a tourniquet is used to reduce arterial inflow and block venous outflow, alongside resistance training, represents an innovative treatment approach for people with PAD. A feasibility study which delivered a supervised BFR programme demonstrated high adherence and excellent safety, as well as improvements in functional capacity, walking pain and quality of life. However, as implementation of a community-based intervention would be difficult, we need to coproduce a bespoke, home-based, self-managed BFR-based intervention.
The aims of this study are:
Phase 1: to produce a home-based intervention, modelled on our community-based BFR exercise programme.
Phase 2: to estimate the rates of recruitment, compliance, and retention for a definitive trial; to estimate the outcome completion rate at the follow-up visit; and to refine a cost-effectiveness analysis framework.
Phase 3: to conduct post-intervention interviews with participants to refine the intervention's processes.
Who can participate?
Patients with PAD with stable claudication (i.e., symptoms unchanged for 6 months)
What does the study involve?
Phase 1: We will conduct focus groups and/or additional interviews with patients to co-produce the intervention. Once the intervention is developed, a workshop will refine it.
Phase 2: Following baseline assessments, participants will be randomly allocated into one of two groups: Group A will follow the developed intervention (BFR-based exercise and health advice) and standard therapy; Group B will receive standard therapy only.
Although the intervention particulars will be defined in Phase 1, it will be self-managed, with regular personal contact with a facilitator. Assessments will be repeated at 3 and 6 months. We will then interview participants (Phase 3) to hear about their programme experience.
What are the possible benefits and risks of participating?
Not provided at time of registration
Where is the study run from?
Sheffield Health Partnership University NHS Foundation Trust (UK)
When is the study starting and how long is it expected to run for?
June 2026 to December 2029
Who is funding the study?
National Institute for Health and Care Research (NIHR) (UK)
Who is the main contact?
1. Prof. Markos Klonizakis, m.klonizakis@shu.ac.uk
2. Dr Tom Parkington, t.parkington@shu.ac.uk
Contact information
Principal investigator, Scientific
Collegiate Crescent Campus, Sheffield Hallam University
Sheffield
S10 2BP
United Kingdom
| Phone | +44 (0)1142255697 |
|---|---|
| m.klonizakis@shu.ac.uk |
Public
Collegiate Crescent Campus, Sheffield Hallam University
Sheffield
S10 2BP
United Kingdom
| Phone | +44 (0)1142252262 |
|---|---|
| t.parkington@shu.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomized controlled trial |
| Secondary study design | Randomised controlled trial |
| Scientific title | Exploring the feasibility of using home- and blood flow restriction-based exercise in combination with health coaching for the management of peripheral arterial disease |
| Study acronym | CALIBRE-IC |
| Study objectives | The main hypothesis is that it is feasible to design and implement a lifestyle intervention based on blood flow restriction (BFR) exercise. The study objectives are: Phase 1 (co-production): to produce a home-based intervention, modelled on our community-based BFR exercise programme. Phase 2 (feasibility): 1. To estimate the rates of recruitment, compliance, and retention for a definitive trial 2. To estimate outcome completion rate at follow-up visits 3. To refine a cost-effectiveness analysis framework Phase 3: To refine the intervention's processes. |
| Ethics approval(s) |
Approved 14/01/2026, East Midlands - Leicester Central Research Ethics Committee (2 Redman Place, Stratford, London, E20 1JQ, United Kingdom; -; leicestercentral.rec@hra.nhs.uk), ref: 25/EM/0278 |
| Health condition(s) or problem(s) studied | Peripheral arterial disease |
| Intervention | This is a three-phase study (comprising intervention design and feasibility), informed by the MRC complex interventions framework, using both qualitative (Phase 1: a participatory approach based on focus groups/interviews) and mixed methods (Phase 2: RCT; Phase 3: qualitative study). Total study duration will be 36 months. Phase 1 (intervention co-production): We will gather the views and opinions of pPAD in 3-4 focus groups and/or additional interviews, with the aim of co-designing the intervention format and content, as well as all relevant participant-facing material. Co-designing will be evidence-based; the home-based exercise programme will be centred on published evidence about exercises and on our successful BFR community intervention. Once this information is collected, we will work collaboratively with our PPIE group to produce the intervention, therefore ensuring that the information collected is translated successfully into a practical tool, that participant burden is kept to a minimum and that the documents and resources’ wording is appropriate. We will then conduct a workshop (n = 6) to pilot-test adapted ideas, tools, and resources. Phase 2 (feasibility): Following eligibility confirmation, an appointment will be made for baseline measurements to take place (VISIT 1; 60 minutes). Baseline measurements will be repeated at 3 months (visit 2) and 6 months (visit 3). During follow-up visits, assessors will review participants’ paper resource use diary, as used successfully in our previous feasibility trials. This will be completed by participants during the 6-month intervention, aiming to collect information on PAD-related healthcare visits and expenses to assist in the health-economic exercise. A decision on whether this will be paper- or online-based (alongside all other participant materials) will be made in Phase 1. On follow-up visits, we will also collect information on any exercise-related, non-study-prescribed activities that participants from both groups have taken part in. Participants will also be given information on how to access the study team in a study-related emergency (e.g., landline and/or study email) as well as the fact that they will retain their right to withdraw from the study at any point and without a reason (although giving one will be appreciated). A study debriefing of our findings will take place at the end of the study, in a mode and manner decided in Phase 1. All study participants will receive a "thank you” card at the end of their successful participation in the study. Participants will be randomised remotely to one of two groups (Group A: intervention and standard care; Group B: standard care only) by our study statistician (to ensure allocation concealment), using a computer programme (nQuery Advisor 6.0, Statistical Solutions, Ireland) to generate stratified block randomisation with variable block size. Home-based exercise intervention (Group A): The full intervention details will have been co-designed in Phase 1. However, as it will be evidence-based, certain items will be predetermined. Support materials and separate health coaching session(s) will also be offered to support long-term adherence, with content and mode to be decided in Phase 1. Standard care (both groups): In the wider Yorkshire region (as in most UK regions) there is no SET offer. Therefore, standard care will include regular monitoring as well as the provision of oral and written, tailored information about their condition and the need for making specific lifestyle adjustments (i.e., smoking cessation, diet, and exercise) to prevent secondary cardiovascular disease. Angioplasty, stenting, bypass surgery and/or medication (e.g., naftidrofuryl oxalate) may also be offered, according to participants' individual needs. Phase 3 (qualitative evaluation/post-intervention interviews): The aim of the qualitative component is to explore participants’ acceptability of the intervention and study procedures. A sub-sample of 12 participants will be recruited by using purposive sampling (a mixture of genders and younger and older participants from both groups). Semi-structured interviews of up to 1 hour will be conducted with participants either face-to-face or via telephone (participants’ preference) after the 3-month follow-up visit. Transcripts will be analysed thematically by using framework analysis. An audio recording of the interviews will be made and then transcribed verbatim, and the five stages of framework analysis (familiarisation, thematic framework identification, indexing, charting, and mapping) will be followed. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
1. Peripheral arterial disease severity measured using the Ankle Brachial Pressure Index (ABPI) at 3 and 6 months |
| Completion date | 31/12/2029 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | All |
| Target sample size at registration | 84 |
| Key inclusion criteria | 1. Patients with PAD with stable claudication (i.e., symptomatic presentation unchanged for 6 months) 2. Ankle–brachial index (ABI) ≤0.9 |
| Key exclusion criteria | 1. Stents in the artery system of the thigh; symptomatic presentation of rest pain, skin ulcers, or gangrene 2. Impaired walking by a non-PAD condition (e.g., hip or knee osteoarthritis) or cannot walk without a walking aid |
| Date of first enrolment | 20/06/2026 |
| Date of final enrolment | 20/06/2027 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Pond Street
Sheffield
S1 1WB
England
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | Fully anonymised, de-identified datasets will be available upon reasonable formal email requests for non-commercial requests only to bona fide researchers with a legitimate academic purpose, 3 years after the end of the study by Professor Markos Klonizakis (m.klonizakis@shu.ac.uk) for 4 years, to meet ethical approval constraints. A data sharing agreement will be developed, outlining permitted uses, security measures, and prohibition of onward sharing. The data use agreement will detail the agreed use and appropriate management of the research data to be shared, securing also appropriate acknowledgement of the significant contributions of all parties to creating new value through data sharing, including the researchers who generated the data and the original funder. |
Editorial Notes
16/06/2026: Study's existence confirmed by the NIHR.
