ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12626001174370

Ethics application status

Approved

Date submitted

27/08/2026

Date registered

21/09/2026

Date last updated

21/09/2026

Date data sharing statement initially provided

21/09/2026

Type of registration

Prospectively registered

Titles & IDs

Public title

Wearable Ambulatory Tracking of cardiac rhythm CHanges before and after Transcatheter Aortic Valve Implantation (WATCH-TAVI)

Scientific title

Prospective interventional study and embedded randomized controlled trial evaluating the utility of wearable cardiac rhythm monitoring for identifying arrhythmias in patients before and after transcatheter aortic valve implantation

Additional trial identifiers [1]

Nil known

Universal Trial Number (UTN)

Trial acronym

WATCH TAVI

Related trial records

Health condition

Health condition(s) studied:

Aortic Stenosis

Cardiac Conduction Disease

Condition category

Condition code

Cardiovascular

Other cardiovascular diseases

Intervention/exposure

Study type

Interventional

Description of the intervention or exposure

>> Overview:
Two-part multicentre prospective study:
- Part 1: Pre-TAVI monitoring phase.
- Part 2: Embedded randomised controlled trial comparing wearable cardiac monitoring with standard care (no routine monitoring after discharge).

Part 1 (pre-TAVI): All participants will undergo 28 days of wearable cardiac rhythm monitoring.

Part 2 (post-TAVI): Participants will be randomised to either the intervention arm (a second wearable monitor for 28 days) or standard care (no routine cardiac monitoring), with follow-up at 1 month and 1 year in both arms.

>> Timing:

Part 1:
The timing of pre-TAVI monitoring relative to the TAVI procedure will vary according to procedural urgency (affecting lead time between workup admission, Heart Team approval for TAVI and scheduled procedure). However, based on average wait times, the 28-day monitoring period is expected to commence approximately 2–3 months before TAVI.

Part 2
Participants will automatically proceed to Part 2 unless they have withdrawn consent or newly meet an exclusion criterion. Relevant exclusion criteria include a requirement for permanent pacemaker implantation identified either during the pre-TAVI monitoring phase or within 4 hours following TAVI. Decisions regarding pacemaker implantation will remain at the discretion of the treating or implanting cardiologist at each participating site. Eligible participants will undergo 1:1 randomisation at 4 hours after TAVI using a computer-generated randomisation sequence, stratified by age and sex. Participants allocated to the control group may subsequently receive ambulatory cardiac monitoring if clinically indicated by their treating specialist. Otherwise, optional ambulatory cardiac monitoring will not routinely be offered at any follow-up timepoint.

>> Device Use:
- Participants will be fitted with the wearable cardiac rhythm monitor (HeartBug) during their TAVI workup hospital admission. This is a routine admission before waitlisting for TAVI, during which necessary preparatory investigations such as CT imaging and coronary angiography are performed.
- Initial device fitting and education will be provided by a member of the research team or the Structural Heart Team Clinical Nurse Consultant who has received appropriate training from the device company, HeartBug. Participants will also be provided with a 4-week supply of adhesive stickers.
- Participants will be instructed to download the HeartBug application to their own mobile device or that of a family member. The application allows participants to monitor device progress and flag symptoms occurring while the monitor is connected. Participants or families unable to use the application would have been considered unable to comply with wearable monitoring and therefore excluded from the study.
- The application provides real-time information regarding device adherence and alerts participants if the device becomes inadvertently disconnected. It also enables participants to access troubleshooting assistance from the device company and request additional adhesive stickers to be mailed to them.
- At the completion of the 4-week monitoring period, participants will be instructed either to return the device to the company using a supplied pre-paid envelope (supplied by device company) or to return it to a designated drop-off box at Royal North Shore Hospital or North Shore Private Hospital.

Participants will be encouraged to wear the device continuously throughout the 28-day monitoring period, except where temporary removal is recommended, such as during swimming or bathing. No specific exercises, training, materials or homework are required beyond the initial device fitting and education session, which takes approximately 10 minutes.

Additional instructions provided to participants regarding device use include:
• Avoid wearing very tight or restrictive clothing as the device needs to maintain good contact with the skin for an accurate reading.
• Avoid activities that may cause significant impact or pressure on the area where the device is placed.
• The device is waterproof and you can wear it while you shower, but it cannot be submerged, so please temporarily remove it for swimming or a bath.
• Avoid strong electromagnetic fields, such as MRI machines or certain electronic devices. In most cases, you will just be instructed to temporarily remove the device while you have an MRI scan, and you can replace it once you leave the radiology area, but in this circumstance please confirm with your local doctor or contact the research team
• Generally, stickers will last about a week. If one falls off, just replace it in the same spot. It can take up to an hour for them to bind properly. To replace the device after removing it, you simply apply new adhesive stickers, connect the device to the stickers, and confirm it is working in the app. There is no need to otherwise regularly change stickers, and excessive changing of the stickers can be irritating to the skin.
• If mild skin irritation develops, participants may contact the research team for advice, reposition a new sticker slightly adjacent to the affected area to reduce ongoing irritation, or apply moisturising cream or DermAid 1% spray (available over the counter) to the affected area.

No routine cleaning or maintenance is required other than adhesive sticker replacement as described above. The instructions relating to the use of the wearable monitor are the same for both Part 1 and 2.

>> Interpretation and Management of Findings from Wearable Monitoring:
- Rhythm data will be analysed in real-time with events logged and categorised by trained cardiac technicians using both the device company and research team technicians. All detected arrhythmias will be co-adjudicated by the cardiac technician and core lab electrophysiologists. Core lab will consist of multidisciplinary research team including structural and interventional cardiologists, electrophysiologists, imaging cardiologists, cardiac technicians and research nursing staff.
- Continuous rhythm monitoring recording will continue for the period of 28-days regardless of the patient reaching composite primary endpoint (to continue monitoring for other end points).
- If a potentially clinically relevant finding is identified, it will be communicated promptly to the participant’s treating cardiologist. Participants will be informed during the consent process that incidental findings may occur and that these will be reported to their clinical team for appropriate follow-up.
- Participants will also be advised that the wearable rhythm monitoring device does not provide real-time clinical supervision and is not a substitute for emergency medical care. Any follow-up investigations or interventions prompted by findings will be undertaken as part of standard clinical care, with the participant’s treating clinician responsible for management.

>> Additional
Additional activities or processes in the study only relate to data collection timepoints. This research does not relate to or dictate any part of the TAVI procedure itself.

Intervention code [1]

Early detection / Screening

Intervention code [2]

Treatment: Devices

Description of the comparator or control

The control arm is standard care including discharge at the cardiologist’s discretion, no routine cardiac monitoring after discharge and follow up clinic visits at 1 month and at 12 months.

Control group

Active

Outcomes

Primary outcome [1]

Proportion of participants (without prior aortic valve replacement) in whom a new clinically significant arrhythmia is detected during pre-TAVI wearable cardiac rhythm monitoring. (Part 1)

Timepoint [1]

At the end of 28 day period (pre-TAVI)

Primary outcome [2]

Proportion of participants (without prior aortic valve replacement) with a new clinically significant arrhythmia during post-TAVI wearable cardiac rhythm monitoring within 28 days after TAVI (Part 2)

Timepoint [2]

At the end of 28 day period (post-TAVI)

Secondary outcome [1]

Incidence of major adverse cardiovascular events, defined as a composite of cardiovascular mortality, cardiovascular rehospitalisation or stroke.

Timepoint [1]

1 month and 1 year after TAVI

Secondary outcome [2]

Time to new permanent pacemaker implantation

Timepoint [2]

1 month and 1 year after TAVI

Secondary outcome [3]

Time to commencement of oral anticoagulation for NOAF

Timepoint [3]

1 month and 1 year after TAVI

Secondary outcome [4]

Percentage difference in AF burden before and after TAVI (calculated using % of time in AF on pre-TAVI 28-day wearable cardiac rhythm monitoring vs % of time in AF on post-TAVI 28-day wearable cardiac rhythm monitoring) among participants in whom atrial fibrillation is detected during pre-procedural monitoring

Timepoint [4]

At the end of 28 day period (post-TAVI)

Secondary outcome [5]

Hospital length of stay

Timepoint [5]

At the end of 28 day period (post-TAVI)

Secondary outcome [6]

Pacemaker dependence (among participants who undergo new permanent pacemaker implantation)

Timepoint [6]

1 month after TAVI

Secondary outcome [7]

.Proportion of participants (with prior aortic valve replacement) in whom a new clinically significant arrhythmia is detected during pre-TAVI wearable cardiac rhythm monitoring. (Part 1)

Timepoint [7]

.At the end of 28 day period (pre-TAVI)

Secondary outcome [8]

Proportion of participants (with prior aortic valve replacement) with a new clinically significant arrhythmia detected within 28 days after TAVI. (Part 2)

Timepoint [8]

At the end of 28 day period (post-TAVI)

Secondary outcome [9]

Hospital costs

Timepoint [9]

At the end of 28 day period (post-TAVI)

Eligibility

Key inclusion criteria

• Adults aged 18 years and older with severe AS scheduled for transfemoral TAVI.
• No existing cardiac implantable electronic device
• Ability to provide informed consent and adhere to wearable monitoring

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Healthy volunteers

Key exclusion criteria

• Existing implanted cardiac device
• Inability to comply with wearable monitoring or follow-up.
• Life-expectancy <12 months
• Randomization-specific
• Pacemaker requirement either during pre-TAVI monitoring phase, or within 4 hours post-TAVI (decision regarding pacemaker will be within the jurisdiction of treating or implanting cardiologist at each local site)

Study design

Purpose of the study

Diagnosis

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Allocation will be concealed using sealed opaque envelopes.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Randomisation will occur 1:1 at 4 hours (after TAVI) using a computer-generated randomization sequence, stratified by age and sex.

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

Sample size
The incidence of a clinically significant arrhythmia before TAVI was estimated to be 10%; comprising approximately 5% HGAVB and 5% NOAF. A sample size of 385 participants would provide a margin of error of approximately ±3% using a two-sided 95% confidence interval. Assuming a dropout rate of 5%, 404 participants are required for Part 1.
The incidence of a new clinically significant arrhythmia (HGAVB or NOAF) after TAVI was anticipated to be 5% in the control arm, and 15% in the wearable monitoring arm. Therefore, the minimum required sample size for Part 2 (using two-sided a of 0.05, 80% power and 1:1 randomisation) is 282 participants.
Between Part 1 and Part 2, several points of dropout are anticipated, including 5% of participants with pre-TAVI detected HGAVB requiring permanent pacemaker, 10% of participants with high-risk or persistent HGAVB immediately post-TAVI, and a further 10% estimated withdrawal or exclusions for other reasons. Accordingly, 404 participants enrolled in Part 1 are expected to result in 288 participants completing Part 2, satisfying both sample size requirements.

Analysis
Baseline characteristics will be compared between the two groups using chi-square tests or Fisher exact tests for categorical outcomes, and the independent-samples t-test or Wilcoxon rank-sum test for continuous outcomes, as appropriate. For Part 1, the incidence of clinically significant arrhythmia detected during pre-TAVI monitoring will be reported as a proportion (%) with a two-sided 95% Wilson confidence interval. For Part 2, the primary outcome will be assessed using an intention-to-treat analysis, with secondary analyses incorporating a combination of Kaplan-Meier curves and log-rank tests for time-to-event analyses, multivariate logistic regression and Cox regression for predictors of HGAVB and NOAF separately, and area under the receiver operating curve for assessment of any derived risk prediction scores. Machine learning modelling using clinical, imaging and pre- and peri-procedural rhythm data to derive risk scores predicting permanent pacemaker requirement.

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

31/10/2026

Actual

Date of last participant enrolment

Anticipated

31/10/2029

Actual

Date of last data collection

Anticipated

31/10/2030

Actual

Sample size

Target

404

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

NSW

Recruitment hospital [1]

Royal North Shore Hospital - St Leonards

Recruitment hospital [2]

North Shore Private Hospital - St Leonards

Recruitment postcode(s) [1]

2065 - St Leonards

Funding & Sponsors

Funding source category [1]

Charities/Societies/Foundations

Name [1]

Heart Research Australia

Address [1]

Country [1]

Australia

Primary sponsor type

Hospital

Name

Department of Cardiology, Royal North Shore Hospital

Address

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Northern Sydney Local Health District Human Research Ethics Committee

Ethics committee address [1]

https://www.nslhd.health.nsw.gov.au/Research/ResearchOffice/Pages/HREC.aspx

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

25/03/2026

Approval date [1]

14/05/2026

Ethics approval number [1]

Summary

Brief summary

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure used to treat severe aortic stenosis. A common problem after TAVI is disruption of the heart’s electrical system, which can cause the heart rate to slow and may require a permanent pacemaker. Irregular heart rhythms, such as atrial fibrillation can also occur and may require blood-thinning medication to reduce the long-term risk of stroke. In this study, all patients undergoing TAVI at two centres in Sydney, Australia will receive extended heart rhythm monitoring for 28 days before their procedure. After TAVI, they will be randomly assigned to either standard care, with no routine rhythm monitoring after discharge, or a further 28 days of extended heart rhythm monitoring. Patients will be followed up at 1 month and 1 year after TAVI. The study aims to improve our understanding of baseline conduction disease in severe aortic stenosis and the utility of extended ambulatory monitoring for earlier detection of important rhythm disturbances after TAVI. This can help refine periprocedural risk stratification, inform targeted surveillance and support early discharge pathways.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Prof Ravinay Bhindi

Address

Cardiology Department, Level 5, Royal North Shore Hospital, Reserve Road, St Leonards, NSW 2065

Country

Australia

Phone

+61294632522

Fax

[email protected]

Contact person for public queries

Name

Ravinay Bhindi

Address

Cardiology Department, Level 5, Royal North Shore Hospital, Reserve Road, St Leonards, NSW 2065

Country

Australia

Phone

+61294632522

Fax

[email protected]

Contact person for scientific queries

Name

Ravinay Bhindi

Address

Cardiology Department, Level 5, Royal North Shore Hospital, Reserve Road, St Leonards, NSW 2065

Country

Australia

Phone

+61294632522

Fax

[email protected]

Data sharing statement

Will the study consider sharing individual participant data?

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically