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Online Appendix for the following JACC: Cardiovascular Imaging article
TITLE: Automated
3-Dimensional Analysis of Pre-Procedural Multidetector Row Computed
Tomography to Predict Annulus Plane Angulation and C-Arm Positioning: Benefit on
Procedural Outcome in Patients Referred for Transcatheter Aortic Valve Replacement
AUTHORS: Mariam
Samim, BSC, Pieter R. Stella, MD, PHD, Pierfrancesco Agostoni, MD,
PHD, Jolanda Kluin, MD, PHD, Faiez Ramjankhan, MD, Ricardo P. J. Budde, MD, PHD,
Gertjan Sieswerda, MD, PHD, Emanuela Algeri, MD, Camille van Belle, BSC, Ahmed
Elkalioubie, MD, Francis Juthier, MD, Anouar Belkacemi, MD, Michel E. Bertrand, MD,
Pieter A. Doevendans, MD, PHD, Eric van Belle, MD, PHD
METHODS
Multi-Detector Row Computed Tomography
Pre-procedurally, all patients underwent a contrast enhanced retrospectively ECGgated MDCT scan on either a 64- or 256-slice scanner (Brilliance 64 or iCT, respectively,
Philips Medical Systems, Best, the Netherlands), according to standard scan protocols that
were individually adjusted based on patient body habitus. Tube voltage was 100 or 120 kV,
tube current 200-400 mAs, collimation 64 or 128 x 0.625 mm and gantry rotation time of 270420 ms. The scan range was set from the level of the subclavian arteries to the level of the
head of the femur. A continuous ECG trace was recorded during image acquisition and
images were reconstructed at each 12.5% of the R-R interval, obtaining a total of 8 datasets
per scan (including 37.5% for systole and 75% for diastole).
All scans were performed during mid-inspiratory breath-hold, and during injection of
iodinated non-ionic contrast agent (Ultravist iopromide - 300 mg/mL, Bayer Schering Pharma
AG, Berlin, Germany, Healthcare Tarrytown, New York). Beta-blockers were not routinely
administered prior to scanning.
Data sets were reconstructed and off-line post-processing of MDCT images was
performed on a dedicated workstation.
Automated 3D Image Analysis of MDCT
The MDCT data were sent to an external workstation for dedicated analysis. All scans
were analyzed using a software package and a dedicated 3D aortic valve analysis workflow
(3mensio
ValvesTM,
3mensio
Medical
Imaging
BV,
The
Netherlands,
http://www.3mensio.com). Early systolic images of the aortic root reconstructed at 30 to
37.5% of the R-R interval were selected, as recommended.
The first step of the valve analysis workflow is an automatic segmentation of the
ascending aorta. Alternatively, placing control points in the aorta, the aortic valve, and in the
left ventricle will manually create a centerline. The application now provides an estimated
aortic annulus plane location and orientation. In the next step of the workflow, these must be
refined. This can be done by positioning and rotating the annulus plane as depicted in Figure 2
in order to define the plane that permits the identification of the 3 aortic sinuses4.
In the final step of the workflow, the latero-lateral (LAO, RAO) and cranio-caudal
angles required for a perpendicular orientation of the C-Arm to the aortic annulus plane are
determined. This is done by rotating a virtual C-Arm around the aortic centerline at the
intersection point with the annulus plane (Figure 2B). A simulated angiogram is interactively
updated when the virtual C-Arm is rotated. The respective images are displayed on the screen.
TAVR procedure
TEE was used for all procedures. Patients were premedicated with aspirin and
antibiotics. Heparin was used to maintain an activated clotting time >250 sec. The ACT was
reversed with protamine at the end of the procedure.
Both for the TF and TA-AVR approach, the device-delivering sheath was inserted
before crossing the valve with any wire. Intra-procedural imaging of the aortic valve was
achieved by contrast injection via a pigtail catheter, which was positioned just above the valve
itself and introduced via a femoral artery (the contralateral in the case of TF-AVR). Balloon
aortic valvuloplasty with a 20- or 23-mm balloon was performed under rapid pacing to predilate the native aortic valve. The prosthesis was subsequently deployed under rapid pacing
(180 to 220 beats/min). Exit peripheral angiography was performed to ensure no extravasation
of contrast prior to removal of the femoral sheath. Immediately post-procedure, the sheath
was removed and surgically closed in the operating room by a surgeon or by using 2
percutaneous closure devices (Perclose, ProGlide, Abbott Vascular).
For the purpose of rapid ventricular pacing during TA-AVR, two unipolar epicardial
pacer wires were secured and tested with a high output epicardial pacing system to ensure
ventricular capture at rates of 180-220 bpm.
Procedural success was defined as the implantation of a functional prosthetic valve
within the aortic annulus at the end of the procedure without in-laboratory mortality. Patients
received aspirin (81 mg/day) and clopidogrel (75 mg/day) indefinitely. Warfarin was
substituted for clopidogrel in patients with atrial fibrillation.