‘Super Rehab’: can we achieve coronary artery disease regression? A feasibility study protocol

Introduction Patients diagnosed with coronary artery disease (CAD) are currently treated with medications and lifestyle advice to reduce the likelihood of disease progression and risk of future major adverse cardiovascular events (MACE). Where obstructive disease is diagnosed, revascularisation may be considered to treat refractory symptoms. However, many patients with coexistent cardiovascular risk factors, particularly those with metabolic syndrome (MetS), remain at heightened risk of future MACE despite current management. Cardiac rehabilitation is offered to patients post-revascularisation, however, there is no definitive evidence demonstrating its benefit in a primary prevention setting. We propose that an intensive lifestyle intervention (Super Rehab, SR) incorporating high-intensity exercise, diet and behavioural change techniques may improve symptoms, outcomes, and enable CAD regression. This study aims to examine the feasibility of delivering a multicentre randomised controlled trial (RCT) testing SR for patients with CAD, in a primary prevention setting. Methods and analysis This is a multicentre randomised controlled feasibility study of SR versus usual care in patients with CAD. The study aims to recruit 50 participants aged 18–75 across two centres. Feasibility will be assessed against rates of recruitment, retention and, in the intervention arm, attendance and adherence to SR. Qualitative interviews will explore trial experiences of study participants and practitioners. Variance of change in CAD across both arms of the study (assessed with serial CT coronary angiography) will inform the design and power of a future, multi-centre RCT. Ethics and dissemination Ethics approval was granted by South West—Frenchay Research Ethics Committee (reference: 21/SW/0153, 18 January 2022). Study findings will be disseminated via presentations to relevant stakeholders, national and international conferences and open-access peer-reviewed research publications. Trial registration number ISRCTN14603929.


Overview
Super Rehab has been designed to enable and support successful behavioural change in patients with cardiovascular disease.The predominant focus is on exercise and diet, and all sessions are delivered 1-to-1.The programme will be explicitly introduced by a Cardiologist, ensuring the programme is presented as a meaningful intervention to improve health outcomes as clinician-led services have been shown to enhance participant engagement 1 .The Cardiologist will introduce the concepts involved in the nutritional advice along with the Super Rehab Booklet, provide advice and oversight to both the dietitian and exercise trainers, and conduct further patient clinical reviews at the end of each intervention phase to review cardiovascular risk factors and medications.Super Rehab has three phases: (1) introduction, (2) developing and (3) maintaining (see Figure 1).Introduction lasts 10-weeks, targeting rapid physiological and behavioural change as a key predictor of long-term success 2 .Developing and maintaining phases constitute a tapering of direct support to engender longer-term behavioural adherence alongside residual physiological gains.This draws on the principle of enabling participant learning of lifestyle modifications in differentiated blocks 3 , and studies demonstrate a 'dose-response' with frequent and sustained interventions achieving more clinically meaningful results 4,5 .Practitioners will use autonomy-supportive behavioural techniques, including action planning, goal setting and self-monitoring 6,7 .
The exercise component will be delivered in local community-based exercise facilities, with the last phase offered virtually.The dietary component will either be face-to-face or virtually, depending on individual participant preference.
Phase 1 -Introduction (10 weeks); Exercise: Twice-weekly 1-hour supervised exercise sessions (described below), with once-weekly sessions of prescribed moderate-intensity 'homework'.Weekly body metrics (blood pressure, heart-rate, body mass index [BMI]) will enable goal-setting and biofeedback to encourage adherence.Diet: 30-minute educational sessions every 2-weeks.These will be delivered virtually or built into exercise sessions, minimising patient travel.
Phase 2 -Developing (14 weeks); Exercise: Reduced supervised session frequency to once-weekly, with two sessions of prescribed moderate-intensity homework per week.Body metrics measured and fed back 2-weekly.Diet: A 30-minute "touch-base" session once/month, providing ongoing behavioural support of self-monitoring and goals.
Phase 3 -Maintaining (28 Weeks); Exercise: Supervised sessions reduced to one 4-weekly, with twice weekly prescribed sessions of homework (now higher-intensity aerobic exercise) and once weekly resistance exercise session.Body metrics assessed monthly.Participants will be offered the option of having the supervised sessions in this phase delivered virtually or continuing face-to-face.Diet: A 30minute session 2-monthly, responding to individual barriers and changes in behaviour, where necessary, to support ongoing engagement with nutritional strategy.

Exercise Component -supervised Sessions:
HIIT: Experienced trainers will lead supervised 1:1 exercise sessions incorporating high-intensity interval training (HIIT) based on the Norwegian 4x4 model 8 .This has been repeatedly used in patients with both coronary artery disease (CAD) and metabolic syndrome (MetS), and the evidencebase supports that HIIT is safe in appropriately screened patients [8][9][10] .At the start of each session, participants will be asked about any change in symptoms or medications and have blood pressure and heart rate measured.
The initial session will consist of a graduated, lead-in of moderate-intensity exercise prior to commencement of HIIT in subsequent sessions.Participants will be taught the Borg Rating of Perceived Exertion 11 (RPE; 6-20) to guide exercise intensity.HIIT will be performed on a static bike (or alternative cardiovascular equipment if unable to cycle) and will comprise a 3-minute warm-up; four 4-minute high-intensity intervals at RPE 15 (hard), finishing at RPE 17-18 (very hard); 3 minutes of active recovery at RPE 11-13 (somewhat hard) between each interval; and conclude with 3-5 minute recovery.Heart rate targets for HIIT (85 -95% of heart-rate max) will be estimated with a baseline cardiopulmonary exercise test (CPET) to help gauge exercise intensity alongside RPE.
Trainers will help maintain target intensity and monitor participants throughout for concerning symptoms.Heart rate data, final RPE and duration for each high-intensity interval will be recorded for subsequent analysis.The exercise trainer will feedback data (e.g. total virtual distance cycled or power used) to participants as they work through the programme to highlight visible progress being achieved.
The goal as participants progress through the programme will be to gradually increase their overall workload (via watts or speed) on a weekly basis as they become fitter and stronger.To achieve this, BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s) BMJ Open doi: 10.1136/bmjopen-2023-080735 :e080735.13 2023; BMJ Open , et al.Graby J trainers will gradually increase the bike's resistance or participant's cycle speed, using heart rate response to ensure they remain in their target zone as workload increases.
Resistance Exercises: This has additional benefits, especially for blood pressure [12][13][14] .Sessions will therefore conclude with twenty minutes of resistance training.
This will be based on a short series of circuit training and will rotate muscle groups between sessions to allow recovery and maximise benefit.During the introduction phase trainers will utilise gym resources (free weights and weight machines) to build strength and confidence.In the subsequent developing phase this will switch to resistance against own body weight and bands to ensure patients learn routines that can then be undertaken in their own home in the maintaining phase and beyond.
The specific exercises are not directly prescribed to allow trainers to identify and respond to the individual needs of each participant.They will though be asked to follow this guiding framework and to record the exercises performed: Introducing: Many patients will be deconditioned, therefore initial sessions will begin with 10 -15 repetitions at 40 -50% of the 1 rep-max using free weights or weight machines.When ready (typically after 4 -5 weeks), progress to 60 -80% of the individual's 1 repetition maximum.
Developing & Maintaining: Move to exercises against gravity / own body weight and use of exercise bands so patients should learn exercises they can start to use on their own.Circuits of 10 -15 reps at 60 -80% of the individual's 1 repetition maximum.

Exercise componenthomework Sessions:
To enhance the weekly workload achieved and support long-term behaviour change, participants will be prescribed 'homework' exercise sessions.This will comprise moderate-intensity aerobic exercise (60 -75% of heart-rate max) for 45-minutes in induction and consolidation phases (e.g., brisk walking), and increase to higher-intensity exercise (e.g., hill walking or jogging) in the maintenance phase.A once weekly resistance exercise session using workouts learnt in the supervised session during phases 1 and 2 will be added in phase 3. Participants will be provided with written guidance on effort levels, how to monitor their symptoms, and a heart-rate monitor (MyZone) to support self-directed exercise intensity at the appropriate level.These data will be reviewed at supervised exercise sessions to evaluate progress and provide support and kept for subsequent analysis.
BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s) BMJ Open doi: 10.1136/bmjopen-2023-080735 :e080735.13 2023; BMJ Open , et al.

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Patients will complete pre-session combined photographic/written diet diaries and will be provided with an educational booklet incorporating the key dietary messages and structure.Recognising that there is no 'one-size-fits-all' pattern, the dietitian will work with participants to identify residual barriers to dietary change and potential solutions.The photographic diet diary will help highlight incremental areas for improvement in a straightforward manner.The dietitian will take a patientcentred approach to setting relevant short-term goals specific to the individual they are working with, which will be reviewed and built upon in each session.
The principles and guiding framework for the dietary advice will be: -A focus on dietary patterns, including eating at regular mealtimes with portion control rather than "calorie counting", snack reduction and identifying healthy alternatives; -Reduced refined carbohydrate intake, avoiding starch-based vegetables and refined grains; -Reducing added sugars, making use of diet diaries to highlight 'hidden sugars' as well encouraging low glycaemic index foods in diabetic participants; -Sensible drinking choices, recommending water over smoothies, diet drinks and juices, unsweetened tea/coffee and alcohol in moderation; -Avoidance of ultra-processed foods, such as highly-processed meat and take-away meals; -Choosing healthy sources of protein, encouraging plant-based foods such as pulses and nuts, regular oily fish, low-fat dairy products, eggs and lean unprocessed cuts of meat (if desired); -Avoidance of 'low-fat' products, in favour of natural, whole foods with unsaturated and/or mono-saturated fats; -Educate patients on the importance of swapping saturated fats for mono-and polyunsaturated fats.Examples include identifying approaches to increasing natural, whole foods containing unsaturated fats, encouraging nuts, seeds, oily fish, avocado and extravirgin olive oil; -Increased dietary fibre, focusing on achieving this via diversifying vegetable intake, which encourages satiety, is good for gut and cardio-metabolic health and is good for blood pressure; -Salt restriction.
Where indicated, dietitians will also continue to highlight the importance of smoking cessation.

Behavioural Support:
All practitioners will be required to use the following behavioural support tools in the delivery of Super Rehab.

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Education: Practitioners will reinforce the positive health outcomes that can be achieved with the suggested exercise and dietary changes the programme aims to deliver (i.e., helping patients to understand what to do, and why they are being asked to do it).This will build on their Super Rehab Booklet.Prescribed 'homework' exercises will be personalised to each individual participant, establishing how best they can incorporate this into their lifestyle.

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Problem-solving: Using the principles of a motivational interviewing, or person-centred approach, practitioners will support lifestyle changes by helping participants identify their own barriers or logistical issues to achieving their goals (e.g.money, family or work life, intolerances, time), and how they could overcome these.Example questions and techniques will be provided to trainers in their Super Rehab Manual.

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Social Support: Sustaining long term change is more likely when people have support from their own networks.Participants will be asked to identify their key social support (e.g.partner, friend, child), and how they could help as part of problem solving.Dietitians will be encouraged to recommend participants bring their key social support with them to dietary review sessions, and it will also be suggested that participants perform their homework exercise with them.This will help encourage and support participants, increasing the potential to maintain this lifestyle change in the longer term.

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Goal-setting & Biofeedback: All participants will also be set a series of longer-term goals for their involvement in the programme, typically: a. ≥10% weight loss with a target BMI of 18.5 -24.9 kg/m 2 b.A normal abdominal waist circumference (<80cm women / <94cm men) c.Improvement in cardiovascular fitness.
However, during the in-programme review sessions practitioners will focus on the shorterterm, achievable, relevant goals related to the actions they can take and focus on between sessions that will help them achieve these longer-term goals.E.g., a specific change in food type in their diet rather than the broader outcome of weight loss.There will be follow-up on whether these goals have been met in subsequent sessions.Super Rehab practitioners will follow the SMART goal-setting principles: Specificset a clear target/change for them to make (what, when & where) Measurableensure it can be assessed at future visits Achievableensure the goal is something you (and they) believe they can do Relevantselect goals that ensure a step-wise improvement Time-boundset a realistic time-frame for them to achieve the goal(s) by Changes in body metrics such as weight and abdominal waist circumference will be used within sessions to feedback on performanceboth for positive re-enforcement and to supplement goal-setting.The 1:1 nature of the sessions will be used to develop rapport, engender a working relationship and a level of accountability on the participant to deliver the changes asked of them.
BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)