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Trial registered on ANZCTR


Registration number
ACTRN12622000731796
Ethics application status
Approved
Date submitted
8/02/2022
Date registered
20/05/2022
Date last updated
20/02/2024
Date data sharing statement initially provided
20/05/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
A micro randomised trial (MRT) to test the effects of app-based motivational messages on physical activity and heart rate.
Scientific title
A micro randomised trial (MRT) to test the effects of app-based motivational messages on physical activity and on heart rate via smartphone app compliance in patients with vulnerable coronary artery plaques.
Secondary ID [1] 305428 0
None
Universal Trial Number (UTN)
U1111-1269-8610
Trial acronym
MIRTH - Messages Improving Resting hearT Health
Linked study record
This study is linked to the LIVEPLUS study by augmenting the Physical Activity component of the app as mentioned in the description of the parent study.
This study is a sub-study of the LIfestyle VulnErable PLaqUe (LIVEPLUS) Study (ACTRN12620001151921).

Health condition
Health condition(s) or problem(s) studied:
Sedentary lifestyle 324529 0
Autonomic dysfunction 324530 0
Condition category
Condition code
Cardiovascular 322508 322508 0 0
Coronary heart disease

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Behavioural: Uniform random message delivery. In this arm, the categories and timings of messages will be delivered to participants using a random schedule.
The study app will be available on the Apple App Store and on the Google Play Store. A member of the research team will assist participants to download the app, create a profile, and give a brief demonstration of the various functionalities of the app. The app will have a help section where participants can find detailed written instructions and a brief video tour of the app.
An example of the physical activity notification that will be sent: "Going for a walk can improve your mood and clear your mind."
Specific exercises will not be specified via messages for this study (MIRTH) because it is up to the participant to decide on the physical activity type, duration, and intensity.
Message delivery will be monitored by accessing app analytics to monitor delivery of app notifications to determine whether messages are delivered to participants.
Physical activity can be tracked via Fitbit devices, which our participants will wear 24/7 during the intervention period which will be 90 continuous days at time points 4-6 and 10-12 months.
Baseline data will be collected for a full one month prior to initiating the intervention for the initial 4-6 months, and at month 9 (natural baseline) for the 10-12m study period.
Participants will receive a personalised home program based on the guidelines of the American College of Cardiology Foundation / American Heart Association to treat individuals with stable ischemic heart disease.

The principles we recommend are:
1) Do moderate-intensity aerobic exercise for at least 5 days, preferably 7 days a week. Moderate-intensity aerobic exercise is defined as aerobic exercise at 64% to 76% of maximum heart rate (HRmax) (see Riebe et al. 2018)
2) Increased daily physical activity (e.g., work breaks, gardening, housework).
3) Do strength training at least two days a week. There is no specific training program for everyone, but these general principles are personalised based on baseline activity level and annual progress. Strength training is a form of physical activity that is designed to improve muscular fitness by exercising a muscle or a muscle group against external resistance, for example, body weight, free weights, dumbbells, etc. Body weight training videos of 11-minute duration will be made available. No external equipment will be required. Exercises range from step jacks, toe touching, wall push-ups, to high knee running, bicycle crunches, and high plank to low plank.
The goal of all participants is to achieve at least 150 minutes of moderate intensity aerobic exercise per week.
In addition to the training module, the team has also developed a series of circuit training videos for different intensities for a wide range of fitness and self-confidence levels that can be viewed at any time via the study app. The duration of the circuit training videos ranges from 11-33 minutes including a 5-minute warm up and a 5-minute cool down video.

1. Riebe D, Ehrman JK, Liguori G, Magal M. Chapter 6 General Principles of Exercise Prescription. In: ACSM’s Guidelines for Exercise Testing and Prescription. 10th Ed. Wolters Kluwer/Lippincott Williams & Wilkins, Philadelphia, PA: 2018, 143-179.
Intervention code [1] 322745 0
Behaviour
Intervention code [2] 322993 0
Lifestyle
Comparator / control treatment
Participants who are randomised to not receive a message on a particular day (i.e., no treatment given).
Control group
Active

Outcomes
Primary outcome [1] 330303 0
Number of steps walked within 180 minutes after messages are sent at each decision-making time point (proximal) as determined from Fitbit device data.
Timepoint [1] 330303 0
Cumulative data will be assessed at the end of months 6 and 12 of the intervention.
Secondary outcome [1] 405669 0
Duration of time spent engaged in physical activity within 180 minutes of receiving the message (proximal) as determined from Fitbit device data.
Timepoint [1] 405669 0
Cumulative data will be assessed at the end of months 6 and 12 of the intervention.
Secondary outcome [2] 405670 0
Change in heart rate within the next 180 minutes after intervention (proximal) as determined from Fitbit device data.
Timepoint [2] 405670 0
Cumulative data will be assessed at the end of months 6 and 12 of the intervention.
Secondary outcome [3] 417706 0
Change values of resting heart rate for both Phases 1 and 2 (distal) as determined from Fitbit device data.
Timepoint [3] 417706 0
Cumulative data will be assessed at the end of months 6 and 12 of the intervention.
Secondary outcome [4] 417707 0
Total number of steps walked during both Phases 1 and 2 periods (distal) as determined from Fitbit device data.
Timepoint [4] 417707 0
Cumulative data will be assessed at the end of months 6 and 12 of the intervention.

Eligibility
Key inclusion criteria
1. Intervention group participants from the LIVEPLUS study (ANZCTR registration: ACTRN12620001151921).
2. Adults who can competently use a smartphone (running iOS or Android)
3. Presence of Low attenuation plaque on Coronary Computed Tomography Angiography
4. 18-80 years of age
5. BMI greater than or equal to 22.0 kg/m2
6. Have no contraindications for the LIVEPLUS study
7. Able to give full informed consent
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
People from the Control group participants from the LIVEPLUS study (ANZCTR registration: ACTRN12620001151921) will be excluded.
Additional exclusion criteria for the parent LIVEPLUS study are as follows:
1. History or clinical manifestation of any other significant metabolic, hematologic, pulmonary, cardio- vascular, gastrointestinal, neurologic, immune, hepatic, renal, urologic disorders, or cancer that, in opinion of the investigator, would make the candidate ineligible for the study
2. Non-MRI-compatible implanted devices or implants
3. Estimated glomerular filtration rate (eGFR) less than 30mL/kg/1.73m2
4. Inability to exercise via supine ergometer
5. Claustrophobia
6. Contraindications for adenosine: Sinus node disease (e.g. sick sinus syndrome, symptomatic sinus bradycardia), second- or third- degree heart blocks, unstable angina, bronchospasm (e.g. asthma), heart transplant recipient, history of seizure disorder
7. Contraindications for glyceryl trinitrate: Known nitrate hypersensitivity, severe anaemia, severe aortic or mitral stenosis, hypotension defined as resting systolic blood pressure equal to 89 mmHg.
8. Not suitable for CT coronary angiography due to contraindications
9. Psychiatric or behavioural problems (history of drug and alcohol abuse, eating disorder)
10. Breast feeding or pregnant women, or those intending to become pregnant before the scheduled end of the intervention
11. Concurrent participation in any other interventional study.

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 will be concealed by central randomisation by smartphone/computer.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised sequence generation.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
Intervention model description: Each participant time point is randomised between intervention or non-intervention, during which time participants are randomised to receive messages or to not receive messages.

At each decision time point, the randomisation will be independent of the randomisations and the participants’ responses to delivered activity suggestions from the previous decision time point.
Given the study duration of 90 days, activity suggestions could be randomized up to 90 time points for each participant.
As we expect the participants will receive equal numbers of the intervention and control messages, i.e., randomisation probability of intervention message is 0.5.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
For the primary outcome variables, we will estimate the long term (distal) effect, i.e., improvement from baseline to end of study period (4-6 months and 10-12 months). The two-tailed Paired t- test will be used. We will also estimate the short term (proximal) effect of intervention messages, i.e., improvement within three hours after each decision time point. The weighted and centered least-squares (WCLS) method for analysing longitudinal data under MRT design will be used (e.g., see Klasnja, et al. (2019)). This method is similar to a generalised estimating equation (GEE) approach that adopts the independent working correlation matrix. The covariates include days in study (i.e., from 1 to 90 days), message (i.e., intervention messages versus control), and the interaction term between days and message. The trend of the proximal effect of intervention message over days can be constant, linear, or quadratic. The message will be converted to binary categories (e.g., 0 = control and 1 = intervention) variable, and the variable will be centered by the corresponding randomisation probabilities (i.e., 0.5). The missing values for the intervention and outcome variables can be imputed by the chained equation method, i.e., van Buuren (2011).

The normality assumptions for the primary outcomes will be validated by histograms, quantile-quantile plots, Anderson-Darling tests (goodness of fit to normal distribution), and Shapiro-Wilk skewness tests (skewness for normality) (e.g., Shapiro, et.al (1968)). If normality is failed, then the outcome variable will be taken as logarithm or square root transformation. We will add 0.5 to the zero value before applying the transformations.

2. Klasnja P, Smith S, Seewald NJ, Lee A, Hall K, Luers B, Hekler EB, Murphy SA. Efficacy of Contextually Tailored Suggestions for Physical Activity: A Micro-randomized Optimization Trial of HeartSteps. Ann Behav Med. 2019 May 3;53(6):573-582. doi: 10.1093/abm/kay067.
3. Liao P, Klasnja P, Tewari A, Murphy S. Sample Size Calculations for Micro-randomized Trials in mHealth. Statistics in Medicine 2016; 35: 1944-1971.
4. Shapiro SS, Wilk MB, Chen HJ. A Comparative Study of Various Tests for Normality. J Am Stat Assoc 1968 Dec;63(324):1343-1372. [doi: 10.1080/01621459.1968.10480932]
5. van Buuren, S., Groothuis-Oudshoorn, K. (2011). mice: Multivariate Imputation by Chained Equations in R. Journal of Statistical Software, 45(3), 1–67.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
5/02/2023
Actual
17/08/2023
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
58
Accrual to date
3
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 21246 0
Royal Prince Alfred Hospital - Camperdown
Recruitment postcode(s) [1] 36119 0
2050 - Camperdown

Funding & Sponsors
Funding source category [1] 309786 0
Charities/Societies/Foundations
Name [1] 309786 0
Australian Youth and Health Foundation
Country [1] 309786 0
Australia
Primary sponsor type
University
Name
The University of Sydney
Address
Camperdown NSW 2006
Country
Australia
Secondary sponsor category [1] 312178 0
None
Name [1] 312178 0
Address [1] 312178 0
Country [1] 312178 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 309537 0
Sydney Local Health District Ethics Review Committee (RPAH Zone)
Ethics committee address [1] 309537 0
Research Ethics and Governance Office
Royal Prince Alfred Hospital
Camperdown, NSW 2050
Ethics committee country [1] 309537 0
Australia
Date submitted for ethics approval [1] 309537 0
29/03/2022
Approval date [1] 309537 0
14/06/2022
Ethics approval number [1] 309537 0

Summary
Brief summary
The aim of this study is to evaluate the effectiveness of context-specific physical activity recommendations and activity plans for increasing physical activity in adults with a previous diagnosis of coronary heart disease.

(A) The investigators hypothesise that:
Primary hypothesis:
1. Participants will show a greater improvement in steps walked within 180 minutes of receiving motivational messages compared to not receiving the motivational messages.
Secondary hypotheses:
2. Participants will show a greater improvement in physical activity duration and heart rate within 180 minutes of receiving motivational messages compared to not receiving the motivational messages.
3. Certain times of the day will be more effective in the proximal outcomes in those randomized to the intervention compared to those who are randomized to not receive the intervention.
4. There will be no difference in distal outcomes in Phase 1 of the study compared to Phase 2.

(B) Physical activity can be tracked via Fitbit devices, which our participants will wear 24/7 during the intervention period which will be 90 continuous days at time points 4-6 and 10-12 months.

(C) Baseline data will be collected for a full one month prior to initiating the intervention for the initial 4-6 months, and at month 9 (natural baseline) for the 10-12m study period.

(D) Our intervention will be sent as messages (seen as notifications via the app) according to a random schedule to participants who will be randomised (to either receive or not receive the messages) at each time-point per day during the intervention period.

(E) We will have a smartphone app adapted for this research and we will implement this MRT through it.

(F) Data from this MRT will allow us to further design just-in-time interventions for future digital interventions. Just-in-time interventions are simply providing the right support (messages) at the right time.

(G) The purpose is to provide behavioural support directly corresponding to real-time needs when participants can participate in positive behaviours.

(H) Our hypothesis suggests those participants receiving the intervention messages will show an improvement in physical activity compliance, improvement in heart rate variability, and improvement in heart rate, with an overall improvement in cardiometabolic health at the 12-month time point.

(I) 58 participants will be randomised for 90 days at two time points (4-6m and 10-12m).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 114502 0
Prof Luigi Fontana
Address 114502 0
Level 5 West
D17 – Education and Research Hub, The Charles Perkins Centre
The University of Sydney, Camperdown, NSW 2006
Country 114502 0
Australia
Phone 114502 0
+61 2 8627 7499
Fax 114502 0
Email 114502 0
[email protected]
Contact person for public queries
Name 114503 0
Sayan Mitra
Address 114503 0
Level 5 West
D17 – Education and Research Hub, The Charles Perkins Centre
The University of Sydney, Camperdown, NSW 2006
Country 114503 0
Australia
Phone 114503 0
+61 2 8627 5819
Fax 114503 0
Email 114503 0
[email protected]
Contact person for scientific queries
Name 114504 0
Sayan Mitra
Address 114504 0
Level 5 West
D17 – Education and Research Hub, The Charles Perkins Centre
The University of Sydney, Camperdown, NSW 2006
Country 114504 0
Australia
Phone 114504 0
+61 2 8627 5819
Fax 114504 0
Email 114504 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Non-identifiable participant data will be shared based upon the research proposal and subsequent discretion of the Principal Investigator. This will include all data.
When will data be available (start and end dates)?
Data will be available after completion of the study (2025) and there will be no end date.
Available to whom?
Researchers can contact the PI if they have a research idea.
The Principal Investigator will decide to release data based upon the proposal.
Available for what types of analyses?
This will depend on the research proposal and discretion of the Principal Investigator.
How or where can data be obtained?
Please contact the Principal Investigator by email ([email protected]).


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
21693Study protocolMitra S, Kroeger C, Xu J, Avery L, Masedunskas A, Cassidy S, Wang T, Hunyor I, Wilcox I, Huang R, Chakraborty B, Fontana L. Testing the Effects of App-Based Motivational Messages on Physical Activity and Resting Heart Rate Through Smartphone App Compliance in Patients With Vulnerable Coronary Artery Plaques: Protocol for a Microrandomized Trial JMIR Res Protoc 2023;12:e46082https://www.researchprotocols.org/2023/1/e46082  DOI: 10.2196/46082 382861-(Uploaded-22-01-2024-15-24-13)-Study-related document.pdf



Results publications and other study-related documents

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