PREhabilitation in Patients Awaiting Acute Inpatient Cardiac SurgEry
Phase: NA
Conditions: Cardiac Disease, Aortic Valve Disease, Coronary Artery Disease, Endocarditis, Valve Heart Disease
Sponsor: University of Hull

PREhabilitation in patients awaiting Acute inpatient Cardiac SurgEry (PreP-ACe): A pilot study 
Abstract 
Introduction 
The concept of prehabilitation is well established in cancer and orthopaedic populations. 
However, amongst the cardiac surgery population, this concept is relatively new. Over the last 10 
years, only a handful of studies were published. All the studies focused on elective cardiac 
surgery population. Over the last 5 years, three further registered studies have focused on the 
elective cardiac surgery population. This pilot study will focus on the acute inpatient cardiac 
surgery population. We aim to assess the feasibility and impact of multimodal prehabilitation on 
inpatients waiting for cardiac surgery.  
Methods and analysis  
In advance of the study, we will be conducting a separate audit with the local trusts permission. 
The purpose of the audit is to understand the population that present to our department for 
cardiac surgery. This will hopefully help us identify the number of patients that could benefit from 
the intervention, the demographics, how they present, diagnosis and the potential impact of 
waiting times on these patients. This audit is performed based on pre-collected data from patients 
who had cardiac surgery in 2022. All patients who had cardiac surgery in our department will be 
entered onto an audit database as routine. Information from this database is extracted for national 
audit purposes when required. We will be extracting the required information from this database 
to answer the questions outlined above. All the information will be anonymous. As this information 
is routinely collected by the cardiac audit department, we will be seeking local institutional 
approval for this. 
Trials involving patients should be co-designed with them to improve the engagement and 
success of the program. We will be doing a survey on inpatients waiting for cardiac surgery  in 
Castle Hill Hospital to gauge their interest. These patients will not be enrolled into the main pilot 
study but we will seek their opinion on the intervention and trial design based on their experience 
waiting for cardiac surgery. Patients will be approached in person, informed about the purpose of 
the survey, consented and they will be asked set questions regarding their opinion on the concept 
of inpatient prehabilitation, the patient information sheet, psychoeducation leaflet, and the 
intensity of the program. We will enquire about their interest in participating if they had the 
opportunity. The data collected will be anonymous.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
1
17

This single centre, prospective, pilot feasibility trial will recruit 20 inpatients awaiting cardiac 
surgery. Measurements will be take at the start of the trial, 7 days after intervention, and 14 days 
after the intervention or before the day of surgery. The primary outcome measure will be feasibility 
and practicality of the programme in acute inpatient population. We will be looking into participant 
eligibility, acceptability, recruitment rates, completion rates and barriers to implementing a 
prehabilitation programme. Secondary outcomes include safety (incidence of adverse events 
directly related to the study), improvement in 6 minutes walk test (6MWT), hand grip strength, 
quality of life, anxiety scores and spirometry. At the end of the trial, we will be seeking the 
feedback of the participants to help us improve the design further. 
Ethics and dissemination 
Trial Registration number  
Introduction 
According to the National Adult Cardiac Surgery Audit (NACSA) over 30,000 heart surgeries are 
performed every year in the UK.1 With the increased life expectancy in the UK, the number of 
heart surgeries is unlikely to reduce. Advancing age is often associated with frailty; a physiological 
state of diminished response to stressors due to decreased reserve secondary to multiple 
comorbidities and homeostatic dysregulation.2 Accordingly, it is unsurprising that frail patients 
have poorer outcomes following an illness and incur a higher healthcare cost. There is evidence 
that frailty is a reversible condition with an improvement of diet, and exercise.3 A randomised 
control trial found a combination of resistance training and nutritional supplement led to not only 
an increase in muscle bulk and strength but also improved mobility.3 The possibility of reversing or 
slowing down this medical condition has led to a lot of interest in the subject. 
The concept of prehabilitation whilst not new, has evolved over the years. It has been used to 
describe preoptimization of medical conditions4 to interventions aimed at improving nutritional (N), 
Exercise capacity (E), and worry reduction (W) to reduce the effect of health deconditioning.5 This 
concept has been adopted by the Society of Enhanced Recovery after Surgery (ERAS). 
Regardless of the definition, prehabilitation is any intervention that prepares a patient, before an 
actual stress or physiological insult with the aim of improving their ability to recover. Evidence of 
the benefits of prehabilitation is well established in cancer and orthopaedic patients. However, 
evidence amongst cardiac surgery population is lacking. Prehabilitation is slow to develop in this 
group partly due to the concerns of adverse events amongst those with pre-existing heart 
condition.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
2
17

During the COVID-19 pandemic, waiting times for coronary artery bypass graft (CABG)  increased 
by 94%.1 According to NACSA, it takes an average of 11 days from angiography to surgery for an 
urgent inpatient coronary artery bypass graft (CABG).1 Median waiting time ranged form 7 to 24 
days.1 This is in contrast to the national guidelines stating that these operations should be carried 
out within 7 days.1 Only 34% of acute patients receive their surgery within 7 days in 2019/2020 
compared to 37% in 2017/2018.1 The delay could be due to a multitude of reasons such as 
waiting for anti-platelet therapy to wear off, optimisation of medical conditions, lack of beds in 
tertiary hospitals, or awaiting further investigations. Traditionally, inpatients are told to minimise 
activity and maintain bed rest. This advice is mainly due to fear that physical activity may worsen 
the condition or precipitate complications. In some cases, this has led to a phenomenon now 
know as ‘pyjama paralysis’ where patents become psychologically bed-bound from not being 
encouraged to mobilise or retaining independence whilst being in hospital. As a result of 
prolonged inactivity, patients become deconditioned, leading to extended hospital stays for non-
medical reason. 
Prehabilitation- Nutrition 
Prehabilitation often focus on exercise or physical conditioning. Over the years, there is increased 
realisation of the important role of nutrition in healing, recovery and reduction of complication from 
surgery. In 1985, an analysis of > 150,00 patients found 3.7% to be malnourished and after 3 
weeks of hospitalisation, they had significant worsening of nutritional status.6 Fifteen years later, 
McWhirter identified malnourishment in 40% of the population and this is associated with poor 
recovery.7 Traditionally, malnourishment is associated with a low BMI; the usual picture being 
either an anorexic or older and frailer patient. A study in 2016, reported that 42% of patients 
awaiting cardiac surgery patients were 60 and above, 51.4% were classed as overweight and 
39% had hypolabuminaemia.8 Poor diet of snacking, fast food, and fizzy drinks was associated 
with male smokers with elevated BMI levels.9 The easy availability of affordable fast food have 
contributed to the rise in high BMI in this population. Patients with post- operative complication 
were more likely to have raised BMI and low albumin.8  Illness, surgery, deconditioning and frailty 
are associated with loss of weight and muscle bulk due to the increased nutritional demand. 
Good preoperative nutritional practices have been shown to reduce post-operative hospital stay, 
mortality rates, complications and improved the cardiac rehabilitation outcomes.10 Nutrition in 
combination with exercise increased muscle strength by almost 50% compared to exercise 
alone.3 Nutritional support has been shown to not only reduce 30 days mortality by over 50%, but 
also improve quality of life compared to standard hospital food.11 Given these findings, we would 
assume nutrition to be at the forefront of managing acutely ill patients. Unfortunately, this is often 
not the case. A meta- analysis by Cermak et al concluded that protein supplementation increased 
both muscle mass and strength during resistance exercise irrespective of age.12 Therefore, 
prehabilitation trials should consider the feasibility of increasing protein intake; the building blocks 
of muscle, to help reverse the sarcopenia  processes of ageing, frailty and deconditioning. 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
3
17

Prehabilitation- Exercise 
The discipline of physiology teaches us that coronary blood flow is determined by coronary 
perfusion pressure, perfusion time and vessel wall diameter. In patients without heart conditions, 
blood flow is auto regulated according to the individual’s requirement at a certain point in time. 
However, in disease states, auto regulation is affected. For instance, in patients with ischaemic 
heart disease, the coronary arteries are narrowed. A shortening of perfusion time (diastole), as 
would happen when the heart rate increases, will lead to reduction and possibly obliteration of 
coronary blood flow. This will in turn lead to chest pain (angina) or even precipitate myocardial 
ischaemia (MI). Despite this, exercise interventions have been shown to be safe and beneficial in 
elective patients awaiting CABG.13, 14 Despite the concept of prehabilitation being around for 
many years, there is no standard approach to what constitutes effective prehabilitation. There is 
unclear evidence as to the type of exercise that confers the highest benefit. Various combinations 
of aerobic,14, 15, 16 flexibility,14 strength/ resistance training,15 inspiratory muscle training.15 
Regardless of exercise type, none of the studies reported any increase in adverse events due to 
exercise in elective patients. To date, there are no published trials looking at the feasibility, safety 
or benefits of exercise on inpatients awaiting cardiac surgery. There is concerns that physical 
exertion may induce symptoms or lead to adverse events in inpatient cardiac surgery population. 
However, there is evidence that 45 minutes per day of resistance training improved muscle 
strength, size, and mobility without causing adverse event in frail, elderly population.3 According 
to World Health Organisation, global life expectancy increased by > 6 years but healthy life 
expectancy increased only 5 years between 2000-2019. In addition, COVID-19 has negatively 
impacted on population health. The impact of COVID-19 has been attributed to deconditioning, 
muscle atrophy and decreased exercise capacity.17 A Delphi study conducted by the WHO 
reported that the most common post-COVID symptoms included tiredness, breathlessness, and 
worsening daily function.18 Frailty is associated with muscle wasting, loss of endurance, 
decreased balance and mobility, slowed performance, relative inactivity. All these symptoms, are 
associated with patients requiring cardiac surgery. 
Post-operative pneumonia is one of the commonest complication after cardiac surgery. The 
incidence varies from 2-35% depending on the population and type of surgery; with aortic 
dissection having the highest rate of chest infection.19, 20, 21, 22  A systematic review by Wang et al 
identified age, smoking history, chronic lung disease, and raised body mass index (BMI) to be 
amongst the risk factors for pneumonia after cardiac surgery.22 Patients that suffer from 
pneumonia are over 4 times more likely to die post-CABG, and experience longer hospital stays19 
which translates to increased cost of care. Inspiratory muscle training (IMT) has been shown to 
improve post operative function23, 24, 25 and reduce pulmonary complications.24, 25 Hulzebo et al 
noted that IMT reduced post-operative pulmonary complications by almost 50%, pneumonia by 
25% and in-patient stay by 1 day in high-risk CABG patients.25 Interestingly, IMT and incentive 
spirometry (IS) not only reduced pulmonary complications but also increased the 6-minute walk 
test (6-MWT),23, 24 and reduced the reduction in 6-MWT performance in the first week post-
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
4
17

surgery.24 The improvements in pulmonary function tests, 6-MWT, quality of life and psychosocial 
parameters have been noted with IMT in just 5 days from surgery.23 However, the same study did 
not mention how these improvements related to post-operative complication and inpatient stay. 
We have chosen cardiorespiratory performance, strength/ resistance, flexibility/ balance and 
inspiratory muscle training for the study as we believe they are most appropriate for our 
population. 
Prehabilitation- Worry 
It is not surprising that a new illness diagnosis and news of impending surgery will lead to a 
degree of stress, and worry for patients and their family. This could be a precursor to anxiety and 
depression. Prevalence of depression, anxiety and stress in the CABG population is 20%, 23%, 
and 21% before the surgery.26 Depression, anxiety and stress is attributed to the surgery itself as 
the risk of being depressed decreased by 33% after CABG.27 The impact of cardiac surgery on 
mental health, is not solely due to the wait for the surgery or limited to the pre-operative phase. 
Anxiety, depression, and stress only decrease by 33% after CABG and 20% of those who had 
CABG suffer from new onset of depression months after the operation.27 The INTERHEART study 
found psychosocial factors (depression, stress, critical life condition) increased the risk of 
myocardial infarction by nearly 3.5 times in females and 2.5 times in males.28 Psychosocial factors 
accounted for 43.5% of myocardial infarction in younger patients compared to 25.2% in older 
patient.28 
Whilst the focus has always been skewed towards the physical health, there is mounting evidence 
of interlink between the metal and physical health. Individuals with low resilience have more 
circulating norepinephrine and cortisol which is likely to explain the higher prevalence of 
hypertension in this population.29 Strong emotions such as anger and negative emotions can 
precipitate MI30 Preoperative anxiety is associated with increased risk of mortality by over 80%.26 
A meta analysis by Raven et al concluded that preoperative depression is associated with 
decreased cardiac symptom relief, quicker return of symptom, frequent hospitalisation, and 
increased mortality in the post operative period.27 Post operative depression is associated with 
poor wound healing and increased likelihood of wound infection.27 Mental health problems are 
often multifactorial and whilst difficult to pin-point a single cause, the negative impact on health is 
significant. Despite this, psychological support is often not offered to cardiac surgery population.  
Methods and analysis 
Setting 
This trial will be conducted in Castle Hill Hospital CHH) which is part of Hull University Teaching 
Hospital NHS Trust, a tertiary hospital in United Kingdom. Assessments will be conducted on the 
cardiac surgery and cardiology ward. Ahead of the pilot study, we will be conducting an audit 
looking into patients who had cardiac surgery in 2022. This information will be obtained from an 
existing audit database in the department. All patients who had cardiac surgery in our hospital 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
5
17

have information relating to their admission collected as a routine. This is done for audit, clinical 
assurance and service evaluation purposes. We will be requesting the relevant information for our 
analysis. All patient information will be anonymous. The purpose of this audit is to try and build a 
picture of the population that present for cardiac surgery. We will be interested to know the 
demographic, comorbidities and how the present to the service. This audit should help us identify 
the number of patients that could potentially benefit from our intervention and the potential impact 
of preoperative waiting time on patient outcome such as post-operative complications and post-
operative stay. 
Patient and public involvement (PPI) is very important in ensuring the success of a study or 
program. Whilst our preliminary survey has indicated an interest in prehabilitation, we will be doing 
further interviews to refine the design of this study and of any future studies. Inpatients waiting for 
cardiac surgery will be approached and given information about the project. They will then be 
invited to participate in the survey which is done via 1:1 interview. Once they consent, we will then 
be providing them with details of what the prehabilitation would entail, the patient information 
sheet and psychoeducation leaflet. Patients will be consulted on the frequency, duration and 
intensity of the program. The survey will hopefully identify any potential barriers to success as well 
as solutions to improve engagement. Participants for the PPI will not be recruited into the pilot 
study.  
Potential participants for the pilot study will be identified from the cardiology team on the ward 
and acute admission board in the hospital. The cardiology team will give an indication that the 
patient is likely for surgery and any language barrier. For the purposes of this pilot, only patients 
that present directly to CHH and able to communicate in English will be considered. Initial 
screening for the patient will be done by the research team upon speaking to the cardiology team. 
Eligible participants will be approached by a member of the research team, provided verbal 
information and following that given the patient information leaflet. They will then be allowed some 
time to go through the information. The researcher will then return to ask if they would like to 
participate and consent them if they agree. Once consented, participants will be asked to perform 
the baseline test. Interventions will begin soon after this. Interventions will be delivered as a mix of 
information leaflet, face to face session and online video. Surgery and post-operative 
hospitalisation will take place in the same hospital. 
Objective 
Primary objective 
The primary objective is to determine the feasibility of a prehabilitation program in acute in patient 
population. We will be looking at the eligibility rates, enrolment/ recruitment rates, practicality of a 
prehabilitation program in terms of logistical challenges to developing and implementing the 
program (deliverability), uptake rates, acceptability and completion rates of an inpatient 
prehabilitation program. 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
6
17

Secondary objective 
Secondary objectives are to identify any changes in 6-MWT, hand grip strength, quality of life, 
spirometry and mental health before and after the program. We will be collecting information on 
adverse events, length of stay, complication(s) and readmission during this study. This will give us 
signals for safety concerns and potential efficacy of the program. 
Eligibility criteria 
Inclusion criteria 
All patients over the age of 18 scheduled for acute cardiac surgery will be given consideration to 
participate in this clinical trial. 
Exclusion criteria 
Patients who are unable or unwilling to participate in any of the elements of prehabilitation will be 
excluded. These include those that have cognitive disability (including unconsciousness), cardiac 
or clinical instability, functional or anatomical impairment which impairs ability to participate, 
language barrier or patient refusal. Any language barrier will be identified by the primary clinical 
team and communicated to the research team. These patients will be excluded as we do not have 
the translating facility for the purposes of this study. Patients that have impending surgery within 
72 hours of arrival to hospital will be excluded. Patients who are awaiting surgery in district 
hospitals or outside of Castle Hill Hospital will be excluded. A non-exhaustive list of exclusion 
criteria is included below. 
Cardiac/ clinical instability such as: 
- Recurrent unstable angina/ crescendo angina 
- Untreated decompensated heart failure 
- Malignant arrhythmias awaiting treatment 
- Resting tachycardia (HR>100 bpm) 
- Left ventricular outflow obstruction such as Aortic Stenosis with pre-syncopal or syncopal 
symptoms 
- Unresolved acute pericarditis or myocarditis 
- Second or third degree heart block without pacemaker 
- Aortic Dissection 
- Myxoma 
Functional/ anatomical impairment such as: 
- Severe musculoskeletal conditions that would prohibit exercise 
- Amputees 
- Registered blind 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
7
17

Patient recruitment and screening 
Patients will be identified on admission via the acute admission board and during multi-
disciplinary team (MDT) meeting. All acute patients waiting for cardiac surgery in CHH will be 
eligible to participate in the survey. As such, they will be approached, given information and 
invited to do so by a member of the research team.  
With regards to the pilot study, acute patients over 18 years old are first of all screened according 
to their route of admission (directly to CHH or via a DGH). Those that present directly to CHH and 
able to communicate in English will then be further screened with the above exclusion criteria. 
Whilst an interpreter can be organised for routine hospital care, this cannot be accommodated for 
the purposes of this pilot study. The language barrier may impede the participant from full 
participation. However, if this intervention was being implemented as routine practice or part of a 
bigger trial, the patient information leaflet, consent, questionnaires can be translated into the 
required language. In addition, a translator could be hired when the patient is undergoing the 
intervention. All eligible patients will be invited to participate in the project. They will be 
approached and provided information regarding the study. This will be explained in written and 
oral forms to each participant. Written consent is mandatory prior to any study related measures, 
intervention or questionnaire. Patients will also be asked if they would be happy to be contacted 
after the study to obtain feedback on the program as this guide future development. 
Baseline data collection 
The primary outcome will look into the acceptability of a multimodal acute inpatient prehabilitation 
program for patients and clinical staff. The study aims to identify barriers (if any) to organising, 
implementing and completing an inpatient prehabilitation program. 
Secondary objectives are as follows: 
1.
Recording any physical changes to patient before prehabilitation, 7 days and 14 days after the 
intervention. If the surgery happens any other time before day 7 or 14, The measurements are 
repeated the day before the surgery. Measurements include 
- 6 minute walk test 
- Spirometry 
- Hand grip strength with dynamometer 
2.
Assessing quality of life and mental health before the prehabilitation, after prehabilitation but 
before surgery  
- EuroQoL (EQ-5D-5L) 
- Cardiac anxiety questionnaire (CAQ) 
3.
Identify any safety concerns related to prehabilitation program for this population, if any exist. 
This will be identified by patient reported diary and notes entry from the staff.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
8
17

Patients will be given a diary to document the duration of time they spent exercising, mood and 
any cardiac symptoms.  
Information on post-operative complications and length of in hospital stay will also be collected. 
Intervention 
Nutrition 
Obesity (OR 1.12) and diabetes (OR 2.37) are some of the risk factors associated with coronary 
artery disease.28 Whilst malnourishment is a well recognised health issue, with well recognised 
treatments which have shown to improve patient outcome, the problem in cardiac surgery is often 
one of over-nourishment. We consulted with dieticians in hospital and abroad; despite the 
prevalence of over-nourished of patients, there are no scoring systems to guide the management 
of these patients. Moreover, due to the acute patient population for this study, active weight loss 
1-2 weeks before surgery is discouraged. Due to the short time frame between diagnosis and 
surgery, there was no nutritional supplement or weight loss advice that could be offered.  
We considered the possibility of hospital admission as an opportunity to educate patients on 
nutrition. However, our preliminary PPI revealed that patients did not view their diet or nutrition as 
an issue. We discussed this with a dietician regarding the provision of dietary advice via written 
information and classes. Due to the small numbers in the study, this would likely be one-to-one to 
a non-receptive audience. The hospital dietician is unable to support such intensive input at this 
moment in time. 
In the future, the possibility of nutritional and dietary advice in hospital should be explored. 
However, this needs to be done in a tactful manner to an audience that may not realise they have 
a problem. 
Exercise 
Participants will undergo a combination of aerobic, resistance/ strength as well as balance and 
flexibility exercise. The exercise will be individualised according to the participant’s ability  
Aerobic exercise 
Aerobic exercises will be performed on a cycle ergometer (Watt bike). Due to the nature of the 
acute admission and the lack of evidence in this area, all aerobic exercises will be supervised. 
Patients will be supervised by a trained exercise physiologist and attached to an ECG/ heart  rate 
monitor throughout the exercise. We will be aiming for a low to moderate intensity exercise based 
on the Borg Rating of Perceived Exertion (RPE 11). The patients will be exercised using the 
intermittent protocol of alternating 1 minute moderate and 1 minute low intensity aerobic exercise. 
This duration can be gradually increased during subsequent sessions depending on the patient’s 
ability. Aerobic exercise will be conducted 2- 3 times per week depending on patient’s ability. 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page  of 
9
17

Patients that are unable to use the exercise bikes will be asked to walk or use the arm crank as an 
alternative exercise. Both these activities will be tailored to the individual ability.  
Regardless of the type of aerobic exercise, the aim would be to achieve a target heart rate for 
each patient (40%-50% heart rate reserve). During the exercise, their heart rate will be recorded 
every minute alongside the corresponding exercise wattage. RPE will be recorded at the end of 
each session. 
Resistance/ strength exercise 
Patients will be given the option of an in hospital application (Physiotech) or pictorial and written 
information on how to perform resistance exercise by their bedside. The physiotech application is 
currently in use by the hospital physiotherapy team for other surgeries such as orthopaedic. 
However, this application has not been used in cardiac surgery. The physiotherapy team will be 
tailoring the exercise for the patients and setting the appropriate recommended targets. The 
application will require basic data on age, weight and height. The exercises will be using single-
use resistance bands. Participants are encouraged to perform the exercise as often as possible 
with the aim of achieving at least 2 session per week.  
Patients who are unable to perform the aerobic exercise (eg due to physical limitation or 
symptoms) will be asked to perform resistance exercise only. The frequency of exercise will be 
individualised according to patient’s ability and fitness level. 
Inspiratory muscle training 
Patients at high risk of respiratory complications are given spiroball after the surgery for 
inspiratory muscle training. As part of the prehabilitation, patients will be given spiroball before the 
surgery and taught how to use it. The importance of inspiratory muscle training will be explained. 
Patient can access spiroball training on the physiotech application. The target will be for patients 
to do 3 sets (consisting of 6 breath each), 5 times a day. Preoperative training should also aid 
better post operative compliance.  
Worry 
All study participants will be given a booklet containing psychoeducation information. The booklet 
aims to explain the emotions they may feel whilst being in hospital, symptoms of anxiety, suggest 
how to manage anxiety, behavioural strategies that may help and signposting if they require 
further support. In addition to this, the participants will be given access to audio on guided 
meditation and relaxation. Both the booklet and audio are designed with input from in-house 
clinical psychologist. 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
10
17

Patients will be asked to score themselves on CAQ and EQ-5D-5L on day 0 and on day 7 or day 
before surgery. During the second assessment of CAQ and EQ-5D-5L, patients will be asked if 
they have read or used either the psychoeducation booklet or audio. Hospital staff will be alerted 
of participants that score highly and considered high risk. In addition, they will be referred to the 
clinical psychologist or in-hospital psychiatry liaison team. 
Additional information collection 
All participants will be given a diary. They will be requested to record number of times they 
performed unsupervised exercise, and for how long. They are also asked to document their food 
intake. The diary is also used as a mood monitor. Participants are encouraged to write down how 
they felt, if they used the recommended technique and any benefit they may experience. 
Participants will be interviewed for a feedback on the prehabilitation program. The questions will 
centre around their opinion of the intervention in terms of acceptability, enjoyment, usefulness, 
accessibility and achievability. We will be gauging their reception to the exercise, 
psychoeducation booklet as well as mindfulness audio. 
Patient and public involvement 
New interventions and ideas are more likely to be successful when all stakeholders are involved in 
the planning as much as possible. Prior to designing our program, we interviewed inpatients 
awaiting cardiac surgery and those who had acute cardiac surgery to gauge their interest in 
prehabilitation. All the patients agreed with the concept of prehabilitation. Patients were keen to at 
least try and exercise whilst waiting for surgery. Patients were reporting that they have been told 
to avoid physical activity whilst awaiting surgery. We had mixed reaction the proposed 
psychological intervention. Patients did not want any guidance on nutrition. They felt they knew 
what they needed and did not want nutritional information of their food displayed. Given this and 
the restrictions we have with time and budget, this element of prehabilitation is removed. All the 
patients interviewed admitted to a level of anxiety. This was mostly related to the waiting time for 
surgery, not receiving adequate information regarding the treatment plan and cancellations of 
surgery. Despite this, there was mixed reaction to our suggestion of providing psychoeducational 
information. 
Based on the positive response from our sample group, we have designed our pilot inpatient 
prehabilitation program. Patient involvement will be an ongoing part in our project. We will be 
asking patients who will not be part of the intervention their opinion of the proposed program 
(investigations, assessments and interventions), 
 the information provided to participants, 
potential barriers and how to overcome this. We will be consulting them on the materials and 
patient information sheet that will be provided to the participants. This will help guide us in further 
refining and improving the design of this study as well as future studies.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
11
17

Safety 
Safety of exercise has not been assessed in this group of patients. To ensure safety of 
participants, the interventions will be done within the cardiology and cardiac surgery department 
area in Castle Hill. This enables the participant to have access to round the clock medical and 
surgical care. The exercise will be stopped if the patient develops symptoms such as angina 
(chest pain, or pain radiating down the left arm), arrhythmias or any syncopal symptoms. If the 
symptoms do not improve with rest, they will receive appropriate medical treatment. The exercise 
will then be stepped down in a gradual fashion with the minimum expectation of resistance 
exercise only. Participants who cannot perform at least resistance only exercise will be withdrawn 
from the study and the surgeons will be informed. 
We anticipate that the most intense intervention in this study will be the aerobic exercise. As such, 
it will only be performed under 1:1 direct supervision. Participants who are able to perform the 
aerobic exercise will only exercise until they achieve their target heart rate. If the target heart rate 
is exceeded, the intensity of the exercise will be reduced. If however, they are unable to achieve 
their target heart rate, we will reduce the intensity of the exercise to a level that is acceptable for 
them. At any stage of the intervention, if the patient develop symptoms as described above, the 
intervention will be stopped, they will be assessed and treated by the medical team in the same 
hospital. 
We anticipate some patients with cardiac conditions may experience symptoms of postural 
hypotension which may impact their ability to perform the test. If this occurs, it will be 
documented by the assessor and patients are told to rest before trying the test again. If they are 
unable to perform the test at all, they will be withdrawn from the study. We will record adverse and 
serious adverse events. 
In the event that the patient develop evidence of worsening cardiac condition either related or 
unrelated to the intervention, they will be assessed by the medical team and treated appropriately 
either with alteration of medication or possibly have the surgery expedited. The decision for 
treatment options lie with the medical team directly involved in the patient’s care. The researchers 
will not influence the decision regarding the patient’s treatment.  
We will be sending out questionnaires pertaining to the patient’s mental health. Patient’s that 
score highly or show any features of mental health problem that could impact their safety will 
either be asked to self refer for help or be contacted by a clinical psychologist. The intervention 
offered will depend on the severity of condition.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
12
17

Outcome measures 
The primary outcome is the feasibility and acceptability of the multimodal program. Feedback will 
be obtained from the patient regarding the acceptability, achievability and general interest in the 
program.  
Feasibility will be assessed by determining the number of eligible patients, participants recruited, 
participated and retained at the end of the intervention, the proportion of intervention sessions 
delivered and fidelity of delivery. Moreover, participant recruitment, retention and adherence to the 
intervention will be measured, as well as any adverse events.  
To determine the acceptability of the intervention and to explore barriers and enablers to the 
implementation of the intervention, interviews will be conducted amongst participants, and staff 
involved in referral and intervention delivery. 
Secondary objectives:
• To identify a signal of efficacy for positive changes in physical health exercise, mental wellbeing, 
and quality of life (using tools described); 
• To identify differences in length of hospital stay, complications and readmission rates to hospital 
following surgery compared to usual care (based on previously collected data);  
• Indications of safety concerns with prehabilitation in acute inpatient population. This is based on 
reported adverse events 
The 6 minute walk test, hand grip, quality of life measure, spirometry and cardiac anxiety score 
will be measured at three points, before the intervention, day 7 and day 14 or before the surgery. If 
the surgery happens before day 7, there will only be two measurements. Information on any 
cardiac symptoms and their association with the exercise will be documented.  
The end of the trial is defined as the day of surgery for the last participant. Participants may 
choose to withdraw at any point of the trial. If they are changes in circumstances which would 
impact their ability to complete the trial, they will be withdrawn by the clinician.  
Statistical method 
Data will be analysed at the end of the study. We will be analysing the data for the eligibility rate, 
recruitment rates, number of patient that participated and completed the intervention. We will be 
looking at the number supervised of sessions that were successfully delivered before the surgery 
as well as the number of unsupervised sessions that the participants achieved. Qualitative 
analysis will be used to determine the acceptability of the intervention and barriers to 
implementation.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
13
17

Data of length of stay, complication rates and readmission rates will be collected and analysed. 
These can be compared to national data. Improvement in 6MWT, hand grip, EQ-5D-5L and CAQ 
will indicate potential efficacy of intervention. 
Ethics 
Ethical approval has been obtained from Hull York Medical School ethics committee. We have 
received REC approval via IRAS. 
Data management 
All staff handling patient data will need to comply with hospital data protection policy. The 
research team will need to have evidence of up-to-date Information Governance training. Data will 
be used according to the General Data Protection Regulation (GDPR) regulation. Only authorised 
research members will be given access to the required data. Electronic information on the study 
will be stored on approved devices provided by the institution. Written data obtained from the 
study will be kept in a locked cabinet in the department. All information collected will be 
anonymised. Individuals will not be identified through any reports or publications that result from 
the trial.  
Discussion 
Prehabilitation is one of the recommendations of Enhance Recovery After Surgery (ERAS). 
Although ERAS is well practiced in other surgical population (the society has been around since 
2001), ERAS-C is relatively new (established 2017). Despite this, the implementation of 
prehabilitation in the UK has been slow. A recent survey found that only 13% of cardiac centres in 
the UK offered prehabilitation program to their patients compared to 66% for other surgical 
specialties.31 Only one centre offered multimodal prehabilitation as recommended by ERAS 
(nutrition, exercise, and psychological).31 The reluctance in adopting prehabilitation is likely to be 
multifactorial from financial, logistics, hesitance from clinician due to fear of precipitating an acute 
event, perceived limited waiting time and inconclusive evidence of improving outcome.  
Inpatients waiting for cardiac surgery are well monitored. Being admitted to hospital forces a 
person to accept that they have a problem that need sorting out. This should make them a 
receptive audience to our intervention. If exercise is proven possible in this population, this will 
open the opportunity for larger studies to ascertain its benefit and safety. Once safety is known in 
this population, this may then encourage a wider acceptance of prehabilitation for all population.  
Whilst we are unable to incorporate nutrition into our study, we still firmly believe there is a role for 
nutrition in prehabilitation. However, in the acute setting, this will be limited in the form of advice 
and information. The education will need to be continued post operatively to consolidate the 
knowledge for patients.  
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
14
17

Deterioration in mental health is associated with increased mortality after cardiac surgery.26 
Despite this, mental health has remained a taboo topic up until recently. The younger population 
maybe more comfortable talking about emotions and seeking help. However, the cardiac surgery 
population are generally older and it is not clear if they will take up the psychological intervention 
offered.  
Cardiac surgery is a tertiary service which means that patients could live hundreds of miles from 
the closest centre. Larger studies need to demonstrate the benefits of prehabilitation (if any) for 
the patients and hospitals. Once the benefits and safety of prehabilitation is established, there is a 
need to have prehabilitation centres that are easily accessible to patients to reduce care 
inequality. The centralisation of service also leads to increased strain on the tertiary services. As a 
result, the waiting times for both elective and urgent cardiac surgery have increased over the 
years.1 This waiting time is unlikely to resolve soon enough. Whilst waiting, patients should be 
working on improving their general health and well being. Surgery should not be viewed as an end 
point but an opportunity to improve their general wellbeing.  
References: 
1. National Institute for Cardiac Outcomes Research. National Adult Cardiac surgery audit 
2017-2020.2021.  
2. Fried LP, Ferrucci L, Darer J, et al. Untangling the Concepts of Disability, Frailty, and 
Comorbidity: Implications for Improved Targeting and Care. The Journals of Gerontology: Series A 
2004;59(3):M255-M63. doi: 10.1093/gerona/59.3.M255 
3. Fiatarone MA, O'Neill EF, Ryan ND, et al. Exercise training and nutritional supplementation for 
physical frailty in very elderly people. New England Journal of Medicine;330(25):1769-75. 
4. Knight JB, Subramanian H, Sultan I, et al. Prehabilitation of Cardiac Surgical Patients, Part 1: 
Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation. Seminars in 
Cardiothoracic & Vascular Anesthesia;26(4):282-94. 
5. Arora RC, Brown CHt, Sanjanwala RM, et al. "NEW" Prehabilitation: A 3-Way Approach to 
Improve Postoperative Survival and Health-Related Quality of Life in Cardiac Surgery Patients. 
Canadian Journal of Cardiology;34(7):839-49. 
6. Pinchcofsky GD, Kaminski MV, Jr. Increasing malnutrition during hospitalization: documentation 
by a nutritional screening program. J Am Coll Nutr 1985;4(4):471-9. doi: 
10.1080/07315724.1985.10720089 
7. McWhirter JP, Pennington CR. Incidence and recognition of malnutrition in hospital. BMJ 
1994;308(6934):945-8. doi: 10.1136/bmj.308.6934.945 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
15
17

8. Goncalves LB, de Jesus NMT, Goncalves MB, et al. Preoperative Nutritional Status and Clinical 
Complications in the Postoperative Period of Cardiac Surgeries. Braz J Cardiovasc Surg 
2016;31(5):371-80. doi: 10.5935/1678-9741.20160077 
9. Roberts K, Cade J, Dawson J, et al. Empirically Derived Dietary Patterns in UK Adults Are 
Associated with Sociodemographic Characteristics, Lifestyle, and Diet Quality. Nutrients 
2018;10(2) doi: 10.3390/nu10020177 [published Online First: 20180206] 
10. Arai Y, Kimura T, Takahashi Y, et al. Preoperative nutritional status is associated with 
progression of postoperative cardiac rehabilitation in patients undergoing cardiovascular surgery. 
General Thoracic and Cardiovascular Surgery 2018;66(11):632-40. doi: 10.1007/
s11748-018-0961-7 
11. Baumgartner A, Pachnis D, Parra L, et al. The impact of nutritional support on malnourished 
inpatients with aging-related vulnerability. Nutrition 2021;89:111279. doi: 10.1016/
j.nut.2021.111279 [published Online First: 20210422] 
12. Cermak NM, Res PT, de Groot LC, et al. Protein supplementation augments the adaptive 
response of skeletal muscle to resistance-type exercise training: a meta-analysis. Am J Clin Nutr 
2012;96(6):1454-64. doi: 10.3945/ajcn.112.037556 [published Online First: 20121107] 
13. Arthur HM, Daniels C, McKelvie R, et al. Effect of a preoperative intervention on preoperative 
and postoperative outcomes in low-risk patients awaiting elective coronary artery bypass graft 
surgery. A randomized, controlled trial. Annals of Internal Medicine;133(4):253-62. 
14. Steinmetz C, Bjarnason-Wehrens B, Baumgarten H, et al. Prehabilitation in patients awaiting 
elective coronary artery bypass graft surgery - effects on functional capacity and quality of life: a 
randomized controlled trial. Clin Rehabil 2020;34(10):1256-67. doi: https://dx.doi.org/
10.1177/0269215520933950 
15. Hartog J, Mousavi I, Dijkstra S, et al. Prehabilitation to prevent complications after cardiac 
surgery - A retrospective study with propensity score analysis. PLoS ONE 2021;16(7):e0253459. 
doi: https://dx.doi.org/10.1371/journal.pone.0253459 
16. Sawatzky J-AV, Kehler DS, Ready AE, et al. Prehabilitation program for elective coronary 
artery bypass graft surgery patients: a pilot randomized controlled study. Clin Rehabil 
2014;28(7):648-57. doi: 10.1177/0269215513516475 
17. Baratto C, Caravita S, Faini A, et al. Impact of COVID-19 on exercise pathophysiology: a 
combined cardiopulmonary and echocardiographic exercise study. Journal of Applied 
Physiology;130(5):1470-78. 
18. Soriano JB, Murthy S, Marshall JC, et al. A clinical case definition of post-COVID-19 condition 
by a Delphi consensus. Lancet Infect Dis 2022;22(4):e102-e07. doi: 10.1016/
S1473-3099(21)00703-9 [published Online First: 20211221] 
19. Kinlin LM, Kirchner C, Zhang H, et al. Derivation and validation of a clinical prediction rule for 
nosocomial pneumonia after coronary artery bypass graft surgery. Clinical Infectious 
Diseases;50(4):493-501. 
20. Wang DS, Huang XF, Wang HF, et al. Clinical risk score for postoperative pneumonia following 
heart valve surgery. Chinese Medical Journal;134(20):2447-56. 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
16
17

21. Wang D, Abuduaini X, Huang X, et al. Development and validation of a risk prediction model 
for postoperative pneumonia in adult patients undergoing Stanford type A acute aortic dissection 
surgery: a case control study. Journal Of Cardiothoracic Surgery;17(1):22. 
22. Wang D, Lu Y, Sun M, et al. Pneumonia After Cardiovascular Surgery: Incidence, Risk Factors 
and Interventions. Frontiers in Cardiovascular Medicine 2022;9 doi: 10.3389/fcvm.2022.911878 
23. Savci S, Degirmenci B, Saglam M, et al. Short-term effects of inspiratory muscle training in 
coronary artery bypass graft surgery: A randomized controlled trial. Scandinavian Cardiovascular 
Journal 2011;45(5):286-93. doi: 10.3109/14017431.2011.595820 
24. Haeffener MP, Ferreira GM, Barreto SS, et al. Incentive spirometry with expiratory positive 
airway pressure reduces pulmonary complications, improves pulmonary function and 6-minute 
walk distance in patients undergoing coronary artery bypass graft surgery. Am Heart J 
2008;156(5):900 e1-00 e8. doi: 10.1016/j.ahj.2008.08.006 [published Online First: 20081005] 
25. Hulzebos EHJ, Helders PJM, Favié NJ, et al. Preoperative Intensive Inspiratory Muscle 
Training to Prevent Postoperative Pulmonary Complications in High-Risk Patients Undergoing 
CABG SurgeryA Randomized Clinical Trial. JAMA 2006;296(15):1851-57. doi: 10.1001/
jama.296.15.1851 
26. Tully PJ, Baker RA, Knight JL. Anxiety and depression as risk factors for mortality after 
coronary artery bypass surgery. Journal of Psychosomatic Research;64(3):285-90. 
27. Ravven S, Bader C, Azar A, et al. Depressive symptoms after CABG surgery: a meta-analysis. 
Harvard Review of Psychiatry;21(2):59-69. 
28. Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated 
with myocardial infarction in 52 countries (the INTERHEART study): case-control study. 
Lancet;364(9438):937-52. 
29. de Robert SC, Barontini M, Forcada P, et al. Psychosocial stress and low resilience: A risk 
factor for hypertension. [Spanish]. Revista Argentina de Cardiologia 2010;78(5):425-31. 
30. Nawrot TS, Perez L, Kunzli N, et al. Public health importance of triggers of myocardial 
infarction: a comparative risk assessment. Lancet;377(9767):732-40. 
31. Gibbison B, Murphy GJ, Akowuah E, et al. Pre-operative and prehabilitation services in UK 
cardiac surgery centres. Anaesthesia 2023;78(3):388-91. doi: 10.1111/anae.15918 [published 
Online First: 20221117] 
IRAS ID 330859 
Version Number: 3 
Date: 06/11/2023
Page 
 of 
17
17