ANZCTR - Registration

The ANZCTR website is back online for trial registration and updates. We apologise for any inconvenience caused while the site was inactive.

Reset your password and enable multi-factor authentication (MFA)

For ANZCTR account holders: to help ensure the cyber safety of your account, you’ll need to reset your password and set-up multi-factor authentication (MFA) as per the instructions below.

Go to the Login page, click ‘reset password’ and follow the instructions.
Check your email for the link to set a new password.
Create a new password that meets requirements. New passwords must include at least one lowercase letter, one uppercase letter, one number and one special character (e.g. !#$%&@).
Return to the Login page and enter your new password. A verification code will be sent to your email.
Check your email for the code and enter it on the Login page. If the code is entered incorrectly, you can re-enter the correct one or request a new one.

Learn more about MFA and its importance on the Australian Signals Directorate website.

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

ACTRN12625000389404

Ethics application status

Approved

Date submitted

13/04/2025

Date registered

1/05/2025

Date last updated

1/05/2025

Date data sharing statement initially provided

1/05/2025

Type of registration

Prospectively registered

Titles & IDs

Public title

Assessing temperature change during ablation with a temperature sensing probe

Scientific title

Assessing thermal energy conduction distant to the site of catheter ablation: a CLInical trial of a teMperATurE sensing diagnostic electrophysiology catheter

Secondary ID [1]

None

Universal Trial Number (UTN)

U1111-1317-2085

Trial acronym

CLIMATE Trial

Linked study record

Health condition

Health condition(s) or problem(s) studied:

supraventricular tachycardia

atrial fibrillation

atrial flutter

atrioventricular nodal reentrant tachycardia

Condition category

Condition code

Cardiovascular

Other cardiovascular diseases

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Temperature sensing and monitoring of the atrioventricular node using the QDOT MICRO™ catheter (Biosense and Webster, Inc, Irvine, CA). This intervention will replace the standard His Bundle catheter at the His Bundle position (surrogate marker of the atrioventricular node) during cardiac ablation procedures for temperature recording (note: it will not be used for ablation). Recruitment of 2 groups of patients undergoing either atrioventricular node ablation or supraventricular tachycardia ablation with 20 patients in each where temperature monitoring will occur in both groups.

In Group 1, participants will be undergoing clinically-indicated atrioventricular node ablation with permanent pacemakers already in-situ. In Group 2, participants undergoing clinically-indicated supraventricular tachycardia ablations will be consented but only recruited if they have peri-nodal pathways (e.g. atrioventricular nodal re-entrant tachycardia). For both groups, standard electrophysiology study set-up will occur with a decapolar diagnostic electrophysiology catheter in the coronary sinus. Instead of the standard diagnostic electrophysiology catheter placed at the His Bundle location, this will be replaced by the QDOT MICRO™ to measure temperature during ablation. Participants would not receive access to the QDOT MICRO™ if they are not enrolled in the study. A standard mapping system using CARTO3 (Biosense Webster) and intracardiac electrogram analysis system using WorkMate Claris™ (Abbott) will be used. The ablation catheter used will be as per physician discretion and power administration will be standard settings for irrigated (25-35W) or non-irrigated (50W) ablation.

During each ablation lesion, temperature recorded by the QDOT MICRO™ at the His Bundle will be correlated to electrophysiology measurements (junctional speeding or atrioventricular block for Group 1) and distance from ablation catheter to His Bundle until the procedure is completed. Operators will be blinded to the temperature at the atrioventricular node. Adherence assessment is not required as this is a same day procedure. The procedures will be performed by cardiac electrophysiologists in a cardiac catheterisation laboratory with vast experience in these procedures. The procedure duration will take a similar time to usual practiceas the only major change is replacing the His catheter; for Group 1 this is approximately 30-60 minutes and for Group 2 this will take around 60-120 minutes. Participants will be followed-up at 3 months as per routine clinical care with review of symptoms and ECG.

Materials: baseline and 3-month follow-up
1. Short-Form 36 questionnaire (for general quality of life assessment)
https://clinmedjournals.org/articles/jmdt/jmdt-2-023-figure-1.pdf

Intervention code [1]

Diagnosis / Prognosis

Intervention code [2]

Early detection / Screening

Intervention code [3]

Prevention

Comparator / control treatment

No control group

Control group

Uncontrolled

Outcomes

Primary outcome [1]

Temperature change at the atrioventricular node during and post ablation

Timepoint [1]

At time of procedure

Secondary outcome [1]

Association of temperature change at atrioventricular node with distance between ablation catheter and temperature sensing catheter recording temperature

Timepoint [1]

At time of procedure

Secondary outcome [2]

Association of temperature change at atrioventricular node with atrioventricular nodal electrophysiology including onset of atrioventricular block for Group 1 only.

Timepoint [2]

At time of procedure

Secondary outcome [3]

Association of temperature change at atrioventricular node with AH interval

Timepoint [3]

At time of procedure

Secondary outcome [4]

Association of temperature change at atrioventricular node with HV interval

Timepoint [4]

At time of procedure

Secondary outcome [5]

Association of temperature change at atrioventricular node with PR interval

Timepoint [5]

At time of procedure

Secondary outcome [6]

Association of temperature change at atrioventricular node with QRS interval

Timepoint [6]

At time of procedure

Secondary outcome [7]

Association of temperature change at atrioventricular node with onset of AH jump for Group 2

Timepoint [7]

At time of procedure

Secondary outcome [8]

Association of temperature change at atrioventricular node with atrioventricular nodal effective refractory period

Timepoint [8]

At time of procedure

Secondary outcome [9]

Association of temperature change at atrioventricular node with ventriculo-atrial nodal effective refractory period

Timepoint [9]

At time of procedure

Secondary outcome [10]

Association of temperature change at atrioventricular node with atrioventricular Wenckebach cycle length

Timepoint [10]

At time of procedure

Secondary outcome [11]

Association of temperature change at atrioventricular node with junctional speeding

Timepoint [11]

At time of procedure

Secondary outcome [12]

Assess general quality of life and health pre and post-intervention

Timepoint [12]

Baseline and 3 months post-procedure

Eligibility

Key inclusion criteria

For Group 1: Adults referred for atrioventricular node ablation procedure
a. Permanent pacemaker in situ.

For Group 2: Adults referred for supraventricular tachycardia (SVT) ablation procedure (de novo or re-do)
a. Preference for patients with suspected atrioventricular nodal re-entrant tachycardia (AVNRT) based on 12-lead ECG of tachycardia during workup of SVT
b. Patient will be formally recruited to the study once diagnostic EP study documents peri-nodal SVT with preference for patients with AVNRT (patients will be consented for this prior to procedure)

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

1. Pregnancy.
2. Age < 18
3. Unable to provide informed consent.
4. No inducible SVT: i.e. no ablation being performed (Group 2) or arrhythmia not peri-nodal

Study design

Purpose of the study

Diagnosis

Allocation to intervention

Non-randomised trial

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

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

Masking / blinding

Open (masking not used)

Who is / are masked / blinded?

Intervention assignment

Single group

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

The proposed study is descriptive and no statistical infererence will be performed. Thus, no formal sample size or power calculations were performed. A standard group size for an observational interventional device trial has been chosen. Approximately 40 eligible participants, with 20 in each group.

Statistical analysis will be limited to descriptive and univariate analysis for all study endpoints. Descriptive findings will be reported as N(%) for categorical data and median (IQR) for continuous data, Correlation co-efficient will be calculated between temperature sensing data from the different temperature sensing electrodes.

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

5/05/2025

Actual

Date of last participant enrolment

Anticipated

31/05/2026

Actual

Date of last data collection

Anticipated

31/08/2026

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

VIC

Recruitment hospital [1]

Royal Melbourne Hospital - City campus - Parkville

Recruitment postcode(s) [1]

3050 - Parkville

Funding & Sponsors

Funding source category [1]

Government body

Name [1]

Melbourne Health

Address [1]

Country [1]

Australia

Primary sponsor type

Government body

Name

Melbourne Health - Innovation Acceleration Program

Address

Country

Australia

Secondary sponsor category [1]

University

Name [1]

University of Melbourne - Innovation Acceleration Program

Address [1]

Country [1]

Australia

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

The Royal Melbourne Hospital Human Research Ethics Committee

Ethics committee address [1]

https://www.thermh.org.au/research/researchers/ethics

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

22/04/2024

Approval date [1]

03/12/2024

Ethics approval number [1]

Summary

Brief summary

Cardiac catheter ablation is a common treatment for heart rhythm disorders. Catheters are long flexible tubes with electrodes at the tip placed in the heart and deliver heating or cooling thermal injury to disrupt abnormal electrical circuits in the heart (ablation). Many of these circuits are located near the atrioventricular node (AVN), an integral structure of the cardiac electrical system. It is the only normal electrical connection between the top and bottom chambers of the heart maintaining synchronised contraction. Inadvertent damage to the AVN through heating or cooling of nearby structures can result in heart block, requiring pacemaker insertion. This study aims to measure the temperature at the AVN during ablations with a temperature sensor catheter to further understand the AVN properties and reduce the risk of heart block by alerting of its impending damage. 

This study will assess 2 patient groups; Group 1 will undergo intentional clinically indicated ablation of the AVN with pacemakers in-situ, Group 2 will undergo supraventricular tachycardia (a fast heart rhythm condition) ablations where electrical circuits are located near the AVN. During ablation, electrical measurements will be taken and correlated with AVN temperature. We predict during ablation, the temperature sensing catheter placed at the AVN will detect temperature changes and alter AVN electrical properties which may forewarn operators of imminent heart block, indicative of AVN damage. These findings have potential to enhance patient safety during cardiac ablations, change clinical practice and improve our understanding of the AVN and its properties.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

A/Prof Alex McLellan

Address

Department of Cardiology, Royal Melbourne Hospital - City Campus Level 2, 300 Grattan Street, Parkville. VIC 3050

Country

Australia

Phone

+61 393427133

Fax

[email protected]

Contact person for public queries

Name

Danlu Liang

Address

Department of Cardiology, Royal Melbourne Hospital - City Campus Level 2, 300 Grattan Street, Parkville. VIC 3050

Country

Australia

Phone

+61 393427133

Fax

[email protected]

Contact person for scientific queries

Name

Danlu Liang

Address

Department of Cardiology, Royal Melbourne Hospital - City Campus Level 2, 300 Grattan Street, Parkville. VIC 3050

Country

Australia

Phone

+61 393427133

Fax

[email protected]

Data sharing statement

Will the study consider sharing individual participant data?

No
No IPD sharing reason/comment: Individual participant data will not be made publicly available to maintain privacy and confidentiality.

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