Clinical Trial Details
— Status: Not yet recruiting
Administrative data
| NCT number |
NCT05988424 |
| Other study ID # |
RHM CAR0638 |
| Secondary ID |
|
| Status |
Not yet recruiting |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
September 2023 |
| Est. completion date |
September 2024 |
Study information
| Verified date |
August 2023 |
| Source |
University Hospital Southampton NHS Foundation Trust |
| Contact |
Waqas Ullah |
| Phone |
+442381208128 |
| Email |
waqas.ullah[@]uhs.nhs.uk |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
In this study we aim to compare the mapping performance in the left atrium of the established
Pentaray catheter to the newer Octaray catheter.
Description:
Compared with conventional point by point mapping, the use of a multipolar high density
Pentaray catheter (Biosense Webster, Diamond Bar, CA, USA) has been found to produce more
rapid, accurate maps. This catheter has 20, 2mm2 electrodes. Newer, high density mapping
catheters have also been introduced, capable of collecting detailed maps rapidly. Such
catheters include the Orion catheter (Boston Scientific, Marlborough, MA, USA) which has 64,
0.4mm2 electrodes and has been shown to be safe and effective in real world usage, and the HD
Grid (Abbott Cardiovascular, Lake Forest, IL, USA) which has 16, 1mm electrodes and has been
shown to be associated with shorter procedure and fluoroscopy times and better success rates
than conventional circular mapping catheters when used for AF ablation.
Of the above high density catheters, the Pentaray is integrated into the Carto3 system. An
advantage of this platform for mapping is the ability to use the Tissue Proximity Indicator
(TPI) Filter to reduce the number of points collected without contact and improve the
accuracy of the subsequent voltage map.
A novel multipolar catheter, iterating on the previous Pentaray catheter is now being
introduced: Octaray. This has 48, 0.9mm2 electrodes arranged on 8 splines. In preclinical
studies, Octaray has been found to be collect maps faster, at higher density and with greater
accuracy for conduction gaps than the Pentaray. The new catheter has been used safely in
clinical cases.
Methods This is a randomised, prospective, single centre, interventional study, Thirty
patients listed for redo AF ablation procedures on clinical grounds will be included in the
study. Procedures will be under conscious sedation or general anaesthetic as per the
preference of the operator, as will the mode of transeptal access and sheaths used to deliver
the mapping catheter to the left atrium.
At the start of the case, two consecutive LA maps will be taken by the same operator using
the Pentaray and Octaray catheters. In both cases, throughout the study the same catheter
types will be used. For the Pentaray catheter, this will be the standard 4-4-4 spaced
version. The Octaray for the study will be the larger, 20mm spline version, with the
3-3-3-3-3 spacing.
To minimise any learning effect from repeated map collections in the same chamber, patients
will be randomly assigned, using block randomisation, as to whether their first LA map will
be collected using the Octaray or Pentaray. The randomised group the patient is in will be
kept in a sealed envelope which will only be opened on the day of the procedure. All maps
will be respiratory gated. The same sheath will be used for both catheters. For the study
protocol, maps will be taken with first one mapping catheter and then the alternative. The
rhythm during collection will be the same for both maps. Ideally patients would be in sinus
rhythm, with maps collected with coronary sinus pacing. If there were challenges maintaining
sinus rhythm during mapping, maps can be taken in AF (though not a mixture of rhythms). The
setup in terms of window of interest and references will also be identical. The map detail
level will be left at 16 for all maps. The map maximum point density will be left as nominal.
The fill and colour thresholds will be kept unchanged at nominal values. No ablation will be
permitted between the two maps being collected. When the second map is being collected using
the alternative catheter, this will be a new map and not a remap and the prior map will be
hidden from the operator.
In order to control for any matrix collected by the initial catheter in taking the first map,
a completely new study will be used for the second map.
TPI will be on for the entire collection period for both maps. The time when map collection
was started, as well as the fluoroscopy time at that point will be noted. These values will
also be noted at the end of the map collection. The aim of map collection will be to get
entire coverage of the geometry with voltage data. Where this was not possible will be noted.
The time for the catheter to start collecting voltage data will also be recorded, to judge
the delay in TPI filter accepted points for the two catheters.
LA Map volumes will be collected from Carto3. The pulmonary veins and any left ventricle
inadvertently collected will be removed from the geometries to allow quantitative assessment.
Once the mapping phase has been completed, the operator would complete the procedure as to
their usual practice.
There will be no follow up needed for the study. Any acute complications will be noted -
acute in this case being defined as complications occurring up to 30 days post-procedure.
