Online Appendix for the following April 6 JACC article
TITLE: Risk and Fate of Cerebral Embolism After Transfemoral Aortic Valve
Implantation: A Prospective Pilot Study With Diffusion-Weighted Magnetic
Resonance Imaging
AUTHORS: Alexander Ghanem, MD, Andreas Müller, MD, Claas P. Nähle, MD,
Justine Kocurek, MD, Nikos Werner, MD, Christoph Hammersting, MD, Hans H.
Schild, MD, PhD, Jörg O. Schwab, MD, PhD, Fritz Mellert, MD, Rolf Fimmers, MD,
Georg Nickenig, MD, PhD, Daniel Thomas, MD
APPENDIX
Supplementary methods
Inclusion criteria
Study inclusion criteria were: a) severe, symptomatic aortic stenosis with or without
regurgitation and high perioperative risk, b) echocardiographic aortic valve annulus diameter
>20 and <27 mm, and c) diameter of the ascending aorta <45 mm at the sinotubular junction.
Exclusion criteria were contraindications to MRI, such as the post-interventional necessity of
permanent pacemaker implantation, claustrophobia or hemodynamic instability impeding
transport to DW-MRI, hypersensitivity, or contraindication to post-interventional dual platelet
inhibition; sepsis or active endocarditis; excessive femoral, iliac or aortic atherosclerosis,
calcification, or tortuosity; aortic aneurysm; bleeding diathesis or coagulopathy; recent
cerebrovascular accident; mitral or tricuspid valvular insufficiency (> grade II); left
ventricular or atrial thrombus; uncontrolled atrial fibrillation; previous aortic valve
replacement; progressive disease with life expectancy <1 year and inability to give written
informed consent. To identify potential sources of cerebral embolism, pre-interventional
sonography of the carotid arteries, transthoracic and transesophageal echocardiography were
conducted. All patients underwent coronary angiography and cardiac catheterizations with 6
French (F) catheters by use of a Terumo wire.
Cranial MRI and imaging analysis
The imaging protocol included transversal and coronal DWI, transversal T2-weighted turbo
spin echo (Turbo spin echo (TSE); Repetition time (TR) / Echo time (TE): 4800 / 100 ms) and
fluid attenuated inversion recovery (FLAIR; TR/TE 6000/120 ms) sequences. DWI was
performed with a spin-echo echo-planar pulse sequence (TE: 78 ms; TR: 2921 ms; echoplanar imaging factor: 77; field of view: 240 mm; matrix: 128 x 256; section thickness: 5 mm;
intersection gap: 1 mm; total acquisition time, 21.4 seconds) with diffusion sensitization bvalues of 0, 500 and 1000 s/mm2. Apparent diffusion coefficient maps were obtained in all
cases. Follow-up MR imaging was performed at E3, using the same protocol of sequences in
order to assess the presence or absence of a subsequent infarct at the location of the diffusion
abnormality.
Pre-existing brain abnormalities (e.g. microangiopathy, infarctions or atrophy) and the
appearance of new hyperintense lesions in DWI on postoperative scans were evaluated. Only
diffusion abnormalities consistent with embolic lesions were included in the analysis. Diffuse
alterations in the diffusion-weighted image or patterns of watershed ischemia were excluded.
Likewise, post-interventional new lesions were determined on the DWI images with
maximum contrast between lesion and normal tissue signal. For volume quantification of new
hyperintense lesions in DWI, the images were magnified fourfold, the area of lesion was
manually delineated in each image slice by region of interest. For image analysis, the
commercially available software of the MRI unit was used (Viewforum, Philips Healthcare,
Best, The Netherlands).
Transfemoral aortic valve implantation
In the present study only third-generation (18F) devices were used. TAVI was performed with
local anesthesia in combination with a mild systemic sedative treatment. The arterial sheath
for transfemoral insertion of the prosthesis was gained by percutaneous puncture, mainly of
the right femoral artery. Venous (7F) and arterial vascular access sites (6F) were inserted
contralaterally. The aortic valve was passed with a Terumo guidewire and changed to an
Amplatz Super Stiff wire (Boston Scientific Corp.). Balloon valvuloplasty was performed
with a 20- to 25-mm balloon under rapid cardiac pacing The CoreValve® device was
positioned during fluoroscopic guidance and deployed into the valve orifice in a retrograde
approach. Hemodynamic parameters were assessed continuously during the procedure.
Evaluation of post-procedural regurgitations was performed using a supra-aortic angiogram
and transthoracic echocardiography. In case of post-interventional aortic regurgitation >grade
II additional valvuloplasty within the CoreValve® prosthesis was performed. Percutaneous
closure system (Prostar XL, Abbott Inc.) was routinely used for the closure of the 18 F
arterial access sites. During TAVI, the patients received weight-adjusted intravenous heparin
to achieve an activated clotting time of 300 – 350 s for the duration of the procedure.
Additionally, acetylsalicylic acid and clopidogrel hydrogen sulfate were administered as
recommended.