Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12622000918729
Ethics application status
Approved
Date submitted
17/06/2022
Date registered
28/06/2022
Date last updated
28/06/2022
Date data sharing statement initially provided
28/06/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
Coronary physiology and absolute coronary flow in severe aortic
stenosis.
Scientific title
Validation of the use of Rayflow catheter in measuring absolute coronary flow in patients with severe aortic stenosis.
Secondary ID [1] 307382 0
Nil known
Universal Trial Number (UTN)
U1111-1279-5300
Trial acronym
CorFlo-AS validate
Linked study record
N/A

Health condition
Health condition(s) or problem(s) studied:
aortic stenosis 326694 0
coronary artery disease 326695 0
Condition category
Condition code
Cardiovascular 323936 323936 0 0
Other cardiovascular diseases
Cardiovascular 323937 323937 0 0
Coronary heart disease

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Study setting:
This project will take place at MonashHeart, Monash Health. MonashHeart is a high volume transcatheter aortic valve replacement (TAVR) centre in Victoria and is an established academic
cardiothoracic centre. MonashHeart is acknowledged as a leading site for research into coronary physiology and cardiac CT. Annually, over 200 aortic valve implantations (both TAVR and SAVR) and >3000 cardiac CTs are carried out at MonashHeart making recruitment targets achievable.

Patient recruitment:
Patients who are due to undergo aortic valve replacement, either TAVR or SAVR are referred for an invasive diagnostic coronary angiography as part of their routine clinical care and pre-procedural assessment. Potential participants will be identified from referrals to the Structural Heart Disease Service or from referring Cardiology Clinics based at the MonashHeart and Monash Health.

For detailed inclusion and exclusion criteria, please refer to step 5: Key Inclusion criteria and Step 5: Key Exclusion criteria.

Consent:
Potential participants will be identified at the point of referral to the Structural Heart disease service, or other cardiac clinics. They will be provided with the Participant Information and Consent form (PICF) ahead of the coronary angiogram with ample opportunity to discuss the study with members of the research team. They will be informed of the voluntary nature of participation. Consenting will take place before the invasive coronary angiogram, which occurs as part of their routine clinical care.

Cardiac catheterisation protocol:
When the patients will present for their diagnostic angiogram, which is part of the standard clinical work-up prior to aortic valve intervention, we will assess the coronary physiology and the absolute coronary flow using a pressure and temperature sensing guide wire (Pressure Wire X, Abbott, USA) and RayFlow monorail catheter (Hexacath, France). The left main coronary artery will be engaged using a guiding catheter and a guidewire equipped with a pressure a temperature sensor (Pressure Wire X, Abbott, IL) is advanced into the left anterior descending artery (LAD). Resting and hyperaemic indices of coronary physiology are measured using intravenous adenosine infusion to achieve maximal hyperemia. A dedicated monorail catheter (Rayflow, Hexacath, Paris, France) is then advanced over the guidewire into the proximal segment of the LAD. A continuous infusion of normal saline is then infused through this catheter at rates of 15, 20, 25 and 30ml/min to produce a hyperaemic state. The absolute coronary flow measurements are recorded at the different flow rates. The measurements will be repeated in upto three arteries. Obtaining these measurements will add an additional 15minutes to the overall diagnostic angiogram.

A member of the study team will oversee that the protocol is adhered to for all measurements.

This will help understand the significance of concomitant coronary artery disease, which in turn will help guide future management strategies of the coronary artery disease.
Intervention code [1] 323816 0
Treatment: Devices
Comparator / control treatment
No control group.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 331740 0
The saline infusion rate required to achieve maximal hyperaemia [ratio of pressure distal (Pd) to pressure aortic (Pa)] as compared with Pd/Pa measured with an adenosine infusion using the Rayflow catheter and the Pressure wire.
Timepoint [1] 331740 0
At time of coronary angiogram
Secondary outcome [1] 410961 0
Absolute coronary flow which is derived from the Pd/Pa and the temperature drop using the continuous saline infusion (thermodilution principle) using the Rayflow catheter, recorded wirelessly by the CoroVentis software (Abbott, IL). The values will then be transcribed into the medical records.
Timepoint [1] 410961 0
At time of coronary angiogram
Secondary outcome [2] 410962 0
Microcirculatory resistance reserve (MRR) - ratio of coronary flow reserve (CFR) to fractional flow reserve (FFR).
The values of CFR and FFR will be calculated by the CoroVentis software using the readings generated by the Rayflow catheter (as described previously). MRR will then be manually calculated by the study team using the ratio of CFR to FFR.
Timepoint [2] 410962 0
At time of coronary angiogram

Eligibility
Key inclusion criteria
1) Age greater than or equal to 18yrs and less than or equal to 95yr old.
2) Able to provide informed, written consent.
3) Patients with no more that 30% visual stenosis in at least one coronary artery at time of coronary angiography.
4) Patients presenting for a diagnostic angiogram for severe symptomatic aortic stenosis (mean gradient >=40mmHg or Vmax >=4m/s or DI <=0.25 on screening transthoracic echocardiogram
Minimum age
18 Years
Maximum age
95 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1) Left ventricular ejection fraction <=30%
2) Chronic renal impairment, as defined by estimated glomerular filtration rate <=30ml.min/1,73m2.
3) Resting bradycardia, heart rate <=40 beats/min.
4) Myocardial infarction within last three months.
5) Previous coronary artery bypass surgery
6) Unfavourable coronary anatomy that would prohibit safe guidewire passage.
7) Women of childbearing age.
8) Low flow low gradient aortic stenosis.
9) History of asthma precluding use of adenosine.
10) Persistent atrial fibrillation.
11) Prior PCI to target vessel.

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
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Sample size

Measurements in 10 patients of up to three epicardial arteries will be used to obtain measurements (minimum of one vessel per patient), with each artery having four measurements at rates of 15, 20, 25 and 30ml/min. This will give up to 120 measurements, which will be an adequate amount of data to validate the use of this catheter in this patient cohort.

Following data acquisition, all the data will be stored in a database and analysed as follows:

The aim of this study is to validate the use of the Rayflow catheter (Hexacath, France) in patients with severe AS using continuous saline infusion to achieve maximal hyperemia. Thus, the degree of hyperemia achieved by the different saline infusion rates will be compared against the gold standard of continuous adenosine infusion. The numerical agreement between Pd values will be assessed using an intra-class correlation coefficient, with Bland-Altman plots used to assess the limits of agreement.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/08/2022
Actual
Date of last participant enrolment
Anticipated
31/07/2023
Actual
Date of last data collection
Anticipated
31/08/2023
Actual
Sample size
Target
10
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 22579 0
Monash Medical Centre - Clayton campus - Clayton
Recruitment hospital [2] 22580 0
Dandenong Hospital- Monash Health - Dandenong
Recruitment hospital [3] 22581 0
Casey Hospital - Berwick
Recruitment postcode(s) [1] 37833 0
3168 - Clayton
Recruitment postcode(s) [2] 37834 0
3175 - Dandenong
Recruitment postcode(s) [3] 37835 0
3806 - Berwick

Funding & Sponsors
Funding source category [1] 311659 0
Hospital
Name [1] 311659 0
Monash Health
Country [1] 311659 0
Australia
Primary sponsor type
Hospital
Name
MonashHeart, Monash Medical Centre
Address
246 Clayton Road, Clayton VIC 3168
Country
Australia
Secondary sponsor category [1] 313108 0
None
Name [1] 313108 0
Address [1] 313108 0
Country [1] 313108 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311117 0
Monash Health Human Research Ethics Committee
Ethics committee address [1] 311117 0
Level 2, I Block, 246 Clayton Road, Clayton VIC 3168
Ethics committee country [1] 311117 0
Australia
Date submitted for ethics approval [1] 311117 0
31/03/2022
Approval date [1] 311117 0
12/05/2022
Ethics approval number [1] 311117 0
RES-22-0000-265A

Summary
Brief summary
Aortic stenosis(AS) is the most common valvular condition with an increasing prevalence in an ever-ageing population. Historically, the only treatment was surgical valve replacement, but transcatheter aortic valve replacement(TAVR) has emerged as the treatment of choice for those patients at high or intermediate surgical risk.
Coronary artery disease(CAD) is common in patients with AS. But the assessment of CAD severity is challenging as our usual physiological tools are not reliable in this group. One of their problems is that they do not assess coronary microcirculation, which is altered in severe AS. A potential solution would be to measure absolute coronary flow to better understand the microcirculation and lead to more reliable estimates. This project seeks to validate absolute flow in patients with severe AS using a novel catheter, Rayflow(Hexacath, France), that measures coronary flow using thermodilution. Once validated, we would then ascertain if this can translate into routine practice with serial measurements pre and post TAVR.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 119994 0
Dr Adam Brown
Address 119994 0
MonashHeart
Level 2, Monash Medical Centre
246 Clayton Road
VIC 3168
Country 119994 0
Australia
Phone 119994 0
+61 3 9594 4295
Fax 119994 0
Email 119994 0
[email protected]
Contact person for public queries
Name 119995 0
Dr Harsh Thakkar
Address 119995 0
MonashHeart
Level 2, Monash Medical Centre
246 Clayton Road
VIC 3168
Country 119995 0
Australia
Phone 119995 0
+61 3 9594 6666
Fax 119995 0
Email 119995 0
[email protected]
Contact person for scientific queries
Name 119996 0
Dr Harsh Thakkar
Address 119996 0
MonashHeart
Level 2, Monash Medical Centre
246 Clayton Road
VIC 3168
Country 119996 0
Australia
Phone 119996 0
+61 3 9594 6666
Fax 119996 0
Email 119996 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?
De-identified data and the published results will be shared
When will data be available (start and end dates)?
Immediately following publishing results, for upto 5 years
Available to whom?
Available to researchers on submitting a reasonable request.
Available for what types of analyses?
Any purpose as long as a reasonable request is submitted
How or where can data be obtained?
Access will be subject to approval by the Principal Investigator Dr Brown by contacting him on his email: [email protected]


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.