Additional value of 3D rotation coronary angiography with the Allura 3D-CA system versus conventional coronary angiography. The COROTA trial.

Coronary angiography is one of the most commonly performed invasive diagnostic
procedures in the world. During a coronary angiography (CAG) there are multiple
projections performed of the coronary artery with the aim of optimal
determination of the coronary-lumen during screening for potential coronary
stenosis. The number op the performed projections of the coronary system vary
per cardiologist and center. Although generally speaking for a good coronary
determination, there are ad least 2 projections of the right coronary system
and 5 projections of the left coronary -system required. At the presens of a
coronary stenosis, there may be additional projections required for a good
determination of the severity and aspect of the stenosis. This because one as
to look for the optimal projection angle for the involving coronary artery.
For each coronary projection, X-ray contrast injection is being used (Xenetix
or Hexabrix). These x-ray contrast fluids are potential nefrotoxisch. It is
therefore important to inject as minimum as possible of these x-ray contrast
fluids. At each coronary projection, the patient and medical staff are also
exposed to x-ray radiation. It therefore needs no further explanation that the
more coronary projections are being made, the more exposure to potential
harmful x-ray contrast fluid en radiation.
With new software techniques one is searching for possibilities to get the
optimal coronary imaging interpretation with the minimum amount op projections.
The Allura 3D-CA is a software system of Philips with some advanced
possibilities for diagnostic and interventional cardiology. The system has the
possibility to create a 3 dimensional presentation of the coronary arteries. It
also can improve the understanding of the coronary system bij creating a 3D
model of the coronary system. From there an optimal 2D working viewing angle is
provided for coronary interventions. The Allura 3D-CA system therefore performs
a so called coronary rotation projection from LAO 55 to RAO 55 (= 110 degr of
rotation), this rotation is made in 25 degrees cranial angulation. One rotation
projection takes 4 seconds and contrastfluid needed per run will probably be
around 10-12cc for LCA and 8-10cc for RCA. (Xenetix or Hexabrix). However there
is no data if the rotational angiografy makes an even good interpretation of
coronary stenoses possible as the conventional angiography.

- Comparing the interpretation of the coronary system with the conventional
used projections (golden standard) versus the rotational projection and the
reconstructed 3D-coronary model.
-Comparing the used amount of contrast fluid and radiation dose between the
conventional- and the rotation projections.
-There also will take a quantitative interpretation comparison place. For this
a QCA (quantitative coronary angiogram) will be performed at the conventional
projections and compared with the quantitative stenosis scoring on the
3D-reconstruction model on the Allura system.

A total of 60 patients suspected for coronary artery disease which therefore
have to undergo a diagnostic coronary angiogram. A written informed consent
obtained. Renal functions before the procedure will be estimated by calculating
the kreatinine clearence and glomerular filtration rate (GFR), according to the
Cockroff-Gault formula before and where possible 24 hours after the procedure.
Patients who meet the following criteria should be excluded: age < 18 years,
kreatinine clearance <90 ml/min/1.73m2, presens of coronary bypassgrafts,
haemodynamic instability / emergency setting. The coronary angiogram (CAG) is
being performed by a cardiologist in trainee with at least the experience of 50
performed CAG under supervision of a interventional cardiologist. In the
absence of the cardiologist in trainee (or to inexperienced), the procedure is
performed by a interventional cardiologist. The CAG is performed by the
Judkins-technique. First two conventional projections are performed of the RCA
(right coronary artery). In the RAO and LAO projection. After the conventional
projections, an additional rotation projection is performed of the RCA from LAO
55 to RAO 55 (= 110 degr of rotation), this rotation is made in 25 degrees
cranial angulation. After the projections of the RCA, the conventional
projections of the LCA are performed. Usually there are 5 conventional
projections of the LCA made from different angles. The decision for possible
extra conventional projections is made by the supervising interventional
cardiologist during the examination. Additional to the conventional
projections, a rotation projection of de LCA will be performed. The rotation
projection covers from LAO 55 to RAO 55 (= 110 degr of rotation), this rotation
is made in 25 degrees cranial angulation.
During the procedure the used amount of x-ray contrast fluid and radiation dose
are separately registered for the conventional and the rotation projections.
The radiation dose used to determine the table height for the concerning
projection are registered with the total radiation dose for that specific
projection.
After the diagnostic coronary procedure, the obtained projections of the
conventional projection, the rotation projection and the 3D reconstruction
model are independently scored by 2 interventional cardiologists. The coronary
projections are scored for coronary stenosis (severity and numbers), coronary
anatomy (left- or right system dominance; separate ostia LAD/CX; other coronary
anomalies), TIMI-flow, thrombus, dissection and calcification. Stenosis scoring
is performed for each coronary segment (17 segments in total).There will also
be quantitative stenosis scoring performed at the conventional projections and
the 3D reconstruction model. Stenosis scoring (stenosis percentage and length)
in the conventional projections is quantitatively measured by QCA software
(quantitative coronary angiogram) for all 17 coronary segments. With the
3D-reconstruction model quantitative stenosis scoring is performed with the
Allura 3D-CA system for each coronary segment. Patient characteristics and the
obtained data from the coronary projections are analyzed in a database. All
scorings of the coronary segments obtained by the different projection methods
are compared. Specific comparison will take pace fore possible variations in
stenosis scoring, used x-ray contrast fluid and radiation dose at the different
projection techniques.

Safety aspects


A coronary angiogram is a well established procedure and is a frequently used
diagnostic procedure with patients suspected for coronary artery disease.
Worldwide more than thousands of coronary angiograms are performed each month
and makes it one of the most commonly performed invasive diagnostic procedure
in the world. In our study only 2 extra rotation projections are performed
during the CAG. These two extra projections involve additional 20 cc extra
x-ray contrast fluid and 0,4 mSv radiation dose. Patients with pre-existing
poor renal functions are excluded. This way we think that the total amount of
used contrast fluid and radiation dose for the coronary angiogram is acceptable
and still less than in most percutaneous coronary interventions.
Also there are no additional catheters intoduces during the procedure.
If the study-results reveal that rotation projections make a good coronary
interpretation possible, this technique may save x-ray contrast fluid and
radiation dose in the future as a possible replacement for the conventional
coronary projections.

This study allows us to conclude if coronary rotation projections and 3D
reconstruction models allow an even qualitative and quantitaive coronary
interpretation compared with conventional projections. In addition, changes in
contrast fluid and radiation dose between the different projection techniques
may be detected.

Privacy aspects

All subjects have the right to see their own data and to discontinue the study,
without consequences for their treatment.

Ethical aspects

All subjects will receive detailed verbal and written information - given by
the investigator- concerning the nature, purpose and possible risks of the
experiment, before they give their written informed consent.
This study proposal will be submitted to the Committee of Scientific
Investigations in Humans (CMO = Commissie Mensgebonden Onderzoek
Arnhem-Nijmegen) of this hospital for critical judgement and approval.