The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12617001297314
Ethics application status
Approved
Date submitted
2/09/2017
Date registered
11/09/2017
Date last updated
22/01/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Perceptually-regulated exercise testing and training for cardiac rehabilitation
Scientific title
Evaluating the efficacy of perceived effort in regulating intensity during exercise testing and training in patients referred for cardiac rehabilitation
Secondary ID [1] 292802 0
Nil known
Universal Trial Number (UTN)
Trial acronym
PRET-CR
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiac rehabilitation 304616 0
Condition category
Condition code
Physical Medicine / Rehabilitation 303935 303935 0 0
Other physical medicine / rehabilitation
Cardiovascular 303973 303973 0 0
Coronary heart disease

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants randomised to the intervention group will complete a 6-week supervised exercise-based rehabilitation program. Exercise sessions will occur twice per week for one hour, conducted in a rehabilitation gym, and supervised by an Accredited Exercise Physiologist (5+ years experience). Sessions will be provided in small groups of a maximum of 6 participants per group. Exercise training will comprise a 10min warm-up, followed by 30min training at an intensity of RPE 13 on Borg's 6-20 Ratings of Perceived Exertion (RPE) scale. This will be followed by 5min cool-down, totaling 45min of exercise with 30min at the prescribed training intensity. All exercise will be performed on a motorised treadmill.

Adherence with attendance to exercise sessions will be monitored and patients must complete at least 10 exercise sessions (i.e. >80% of sessions) to be included in final analyses. If a patient misses two or more sessions in a row, another week will be added to their program to account for the missing sessions. Adherence with exercise intensity will be monitored by a) by confirming the exercising RPE every 5min during training and b) exercising heart rate will be recorded during every session and compared to the heart rate values corresponding to RPE 13 during the initial exercise testing.
Intervention code [1] 299047 0
Rehabilitation
Comparator / control treatment
Control participants will maintain their usual activities for the 6-week intervention period. Participants in the control group will be offered the intervention after completing follow-up testing (i.e. after 6 weeks)
Control group
Active

Outcomes
Primary outcome [1] 303278 0
Change in maximal oxygen uptake (VO2max) established via symptom-limited graded exercise test (modified Bruce treadmill protocol) with online ventilatory gas analysis.
Timepoint [1] 303278 0
measured at 7 weeks after randomisation
Primary outcome [2] 303279 0
Validity and reliability of predictions of maximal oxygen uptake (VO2max) established via a submaximal perceptually-regulated exercise test (PRET) with online ventilatory gas analysis.
Timepoint [2] 303279 0
Baseline
Primary outcome [3] 303280 0
Sensitivity of predictions of maximal oxygen uptake (VO2max) established via a submaximal perceptually-regulated exercise test (PRET) with online ventilatory gas analysis.
Timepoint [3] 303280 0
at 7 weeks following randomisation
Secondary outcome [1] 338508 0
Change in oxygen uptake at the ventilatory threshold established via symptom-limited graded exercise test (modified Bruce treadmill protocol) with online ventilatory gas analysis. Ventilatory threshold will be identified using the 3-point method (V-Slope, Ventilatory equivalent, and Excess CO2).
Timepoint [1] 338508 0
at 7 weeks following randomisation
Secondary outcome [2] 338509 0
Changes in Oxygen Uptake Efficiency Slope established via a symptom-limited graded exercise test (modified Bruce treadmill protocol) with online ventilatory gas analysis.
Timepoint [2] 338509 0
at 7 weeks following randomisation
Secondary outcome [3] 338510 0
Change in heart rate responses to exercise at RPE 13 measured via beat-to-beat chest strap telemetry
Timepoint [3] 338510 0
at week 6 of intervention period
Secondary outcome [4] 338511 0
Change in VO2 responses to exercise at RPE13 measures via online ventilatory gas analysis.
Timepoint [4] 338511 0
at week 6 of intervention period

Eligibility
Key inclusion criteria
Eligible patients will have had: Acute myocardial infarction (within last 4-16 weeks), Percutaneous coronary intervention (within last 4-16 weeks), and/or Coronary artery bypass surgery (within last 8-16 weeks).
Patients must be physically capable of undertaking moderate intensity exercise on a motorised treadmill
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1) Symptoms of angina present at rest or during submaximal (light) intensity exercise.
2) Unstable angina, myocarditis or symptomatic heart failure (defined as NYHA class III or IV, or LVEF < 40%)
3) Uncontrolled dysrhythmia or high degree atrioventricular block
4) Severe arterial hypertension (defined as >200/100mmHg after 10min seated rest)
5) Sternal instability, severe musculoskeletal deconditioning or any other complications in surgical recovery
6) uncontrolled metabolic disease
7) Pregnant
8) low English proficiency or unable to give informed consent.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
A priori power calculations suggested 24 participants were required to maintain sufficient power (0.80) for a mixed-effects repeated measures ANOVA (2 groups x 2 timepoints) with significance set at p < 0.05. This calculation is based on a f = 0.46 effect size observed in a previous study of healthy adults over an 8-week exercise intervention. To account for an expected smaller effect size in this study compared to the previous study and to allow for 20-30% dropout typically observed in cardiac rehabilitation, 32 participants will be recruited in total.

Data will be analysed by repeated measured ANOVA using the 2 groups and 2 timepoints. Bland & Altmans 95% Limits of agreement and intraclass correlation coefficients will be used to assess the validity, reliability and sensitivity of the perceptually-regulated exercise test (PRET) to predict VO2max compared to direct measurement.
Changes in heart rate and VO2 over the 6-week intervention period (for the intervention group only) will be assessed via repeated measures ANOVA for data collected in week 1 and week 6 of the intervention. Intraclass correlation and coefficients of variation will assess variability within training sessions.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA
Recruitment hospital [1] 8945 0
The Royal Adelaide Hospital - Adelaide
Recruitment postcode(s) [1] 17316 0
5000 - Adelaide

Funding & Sponsors
Funding source category [1] 297433 0
University
Name [1] 297433 0
University of South Australia
Address [1] 297433 0
Corner of North Terrace and Frome Road
Adelaide, SA 5000
Country [1] 297433 0
Australia
Funding source category [2] 297434 0
Charities/Societies/Foundations
Name [2] 297434 0
The Freemasons Foundation Inc.
Address [2] 297434 0
North Terrace
Adelaide, SA 5000
Country [2] 297434 0
Australia
Primary sponsor type
University
Name
University of South Australia
Address
Corner of North Terrace and Frome Road
Adelaide, SA 5000
Country
Australia
Secondary sponsor category [1] 296430 0
None
Name [1] 296430 0
Address [1] 296430 0
Country [1] 296430 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298542 0
University of South Australia Human Research Ethics Committee
Ethics committee address [1] 298542 0
Research and Innovation Services
Mawson Lakes Campus
University of South Australia
GPO Box 2471, Adelaide, SA, 5001
Ethics committee country [1] 298542 0
Australia
Date submitted for ethics approval [1] 298542 0
03/06/2016
Approval date [1] 298542 0
24/10/2017
Ethics approval number [1] 298542 0
Ethics committee name [2] 298543 0
Central Adelaide Local Health Network Human Research Ethics Committee
Ethics committee address [2] 298543 0
Level 3, Roma Mitchell House
136 North Terrace, ADELAIDE SA 5000
Ethics committee country [2] 298543 0
Australia
Date submitted for ethics approval [2] 298543 0
04/09/2017
Approval date [2] 298543 0
18/01/2018
Ethics approval number [2] 298543 0

Summary
Brief summary
The aim of this study is to evaluate the validity, reliability and sensitivity of predicting VO2max from a perceptually-regulated exercise test (PRET) and to evaluate the efficacy of regulated exercise intensity during cardiac rehabilitation using perceived exertion. Specifically, the study will assess how perceptions of effort change over a 6-week exercise program and will quantify these changes in relation to physiological (i.e. heart rate and VO2) and performance (i.e. work rate) indicators of exercise intensity. Participants referred for cardiac rehabilitation, following myocardial infarction or cardiac surgery, will complete a symptom-limited exercise test to establish VO2max and 3 PRETs. Participants will then be randomised to a supervised exercise or wait-list control. Supervised exercise will consist of 6-weeks of exercise training for 1 hour 2x per week. Exercise intensity will be regulated at RPE 13 on Borg’s 6-20 RPE scale. Heart rate will be measures in each session and oxygen uptake objectively measured during the first and last week. Participants will then repeat the symptom-limited exercise test and 3 PRETs.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 77402 0
Mr Braden Mitchell
Address 77402 0
University of South Australia
School of Health Sciences (CEA-14)
GPO Box 2471
Adelaide, SA 5001
Country 77402 0
Australia
Phone 77402 0
+61 8 8302 1309
Fax 77402 0
Email 77402 0
braden.mitchell@mymail.unisa.edu.au
Contact person for public queries
Name 77403 0
Mr Braden Mitchell
Address 77403 0
University of South Australia
School of Health Sciences (CEA-14)
GPO Box 2471
Adelaide, SA 5001
Country 77403 0
Australia
Phone 77403 0
+61 8 8302 1309
Fax 77403 0
Email 77403 0
braden.mitchell@mymail.unisa.edu.au
Contact person for scientific queries
Name 77404 0
Mr Braden Mitchell
Address 77404 0
University of South Australia
School of Health Sciences (CEA-14)
GPO Box 2471
Adelaide, SA 5001
Country 77404 0
Australia
Phone 77404 0
+61 8 8302 1309
Fax 77404 0
Email 77404 0
braden.mitchell@mymail.unisa.edu.au

No data has been provided for results reporting
Summary results
Not applicable