2; mean from circumference: Dcirc; mean from surface area: DCSA] were measured in 75 patients referred for percu-
taneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n ¼ 22; 29 mm: n ¼ 28). Dminand
Dmaxdiffered substantially [mean difference (95% CI) ¼ 6.5 mm (5.7–7.2), P , 0.001]. If Dminwere used for sizing
26% of 75 patients would be ineligible (annulus too small in 23%, too large in 3%), 48% would receive a 26 mm
and 12% a 29 mm CRS. If Dmaxwere used, 39% would be ineligible (all annuli too large), 4% would receive a
26 mm, and 52% a 29 mm CRS. Using Dmean, Dcirc, or DCSAmost patients would receive a 29 mm CRS and 11,
16, and 9% would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing
based on DCSAand Dmean(76%, 74%), but undersizing occurred in 20 and 22% of which half were ineligible
(annulus too large).
Eligibility varied substantially depending on the sizing criterion. In clinical practice both under- and oversizing were
common. Industry guidelines should recognize the oval shape of the aortic annulus.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Percutaneous † Transcutaneous † Aortic valve † Sizing † Aortic root
Valvular heart disease
Three dimensional evaluation of the aortic
annulus using multislice computer tomography:
are manufacturer’s guidelines for sizing for
percutaneous aortic valve replacement helpful?
Carl J. Schultz1, Adriaan Moelker2, Nicolo Piazza1, Apostolos Tzikas1, Amber Otten1,
Rutger J. Nuis1, Lisan A. Neefjes2, Robert J. van Geuns1,2, Pim de Feyter1,2,
Gabriel Krestin2, Patrick W. Serruys1, and Peter P.T. de Jaegere1,3*
1Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands;2Department of Radiology, Erasmus MC, Rotterdam, The Netherlands; and3Department of Interventional
Cardiology, Erasmus MC, Room Ba 587, PB 412, Rotterdam 3000 CA, The Netherlands
Received 22 May 2009; revised 1 July 2009; accepted 20 August 2009; online publish-ahead-of-print 7 December 2009
To evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT)
aortic annulus measurements on Corevalve (CRS) size selection.
Multislice computer tomography annulus diameters [minimum: Dmin; maximum: Dmax; mean: Dmean¼ (Dminþ Dmax)/
Percutaneous aortic valve replacement (PAVR) is increasingly being
used to treat patients with severe aortic stenosis who are thought
to be high risk or ineligible for surgery.1–9Optimal valve function
relies on, among others, accurate sizing, i.e. selection of prosthesis
size to match patient anatomy. In contrast to surgical AVR where
sizing is done under direct vision, the use of imaging of the aortic
root is mandatory for sizing before PAVR.
The aortic annulus, on which sizing is based, is defined as a
virtual ring with three anatomical anchors at the nadir of each
aortic leaflet, i.e. the three caudal points of the crown shaped
line of attachment of the leaflets.10Patient matrices provided by
the manufacturers are used in clinical practice for the selection
of the valve size and are based on transthoracic echocardiography
(TTE) or transoesophageal echocardiography (TEE) defined
annulus dimensions. Yet, TTE and TEE produce 2D tomograms,
whereas the aortic root has a complex 3D geometry, with a
base (annulus) that is often elliptical.10Furthermore, one cannot
precisely appreciate the exact position for the measurement of
annulus diameter, which by definition should go through the
centre of the virtual ‘ring’, thereby leading to underestimation of
*Corresponding author. Tel: þ31 10 463 56 56, Fax: þ31 10 463 53 41, Email: firstname.lastname@example.org
Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2009. For permissions please email: email@example.com.
European Heart Journal (2010) 31, 849–856
by guest on June 8, 2015
annulus dimension.11–18In contrast, with a 3D imaging modality
such as cardiac multislice computer tomography (MSCT), multiple
axial diameter measurements of the non-circular annulus are
We assessed the geometry of the aortic root with dual source
MSCT in 75 patients with severe aortic stenosis who were referred
for PAVR. The purpose of this study was to evaluate the effects of
applying current sizing guidelines to different annulus diameter
measurements on size selection of the CoreValve RevalvingTM
This study complies with the declaration of Helsinki. Seventy-five
patients with severe aortic stenosis who had MSCT for the purpose
of assessment of the peripheral vessels and determining the optimal
C-arm angulation in preparation of the PAVR procedure were
studied, of whom 50 subsequently had PAVR with implantation of a
CRS prosthesis (size 26 mm in 22 and 29 mm in 28 patients). In
these patients, the operator selected CRS size during PAVR on the
basis of a combination of clinical variables (gender, body height, and
weight), visual assessment of the left ventricular outflow tract
(LVOT) and aortic root on TTE and contrast angiography of the
aortic root. Detailed measurements of the annulus on MSCT were
not available at the time of PAVR.
Multislice computer tomography acquisition
All patients were scanned using dual source CT (Somatom Definition,
Siemens Medical Solutions, Forchheim, Germany). The system is
equipped with two X-ray tubes and detectors offset by 908 on a
Multislice computer tomography scanning parameters were: 2?
detector collimation of 32 ? 0.6 mm with a z-axis flying focal spot,
rotation time 330 ms, tube voltage 120 kV. The pitch varied between
0.2 for low heart rates (,40 b.p.m.) and 0.53 for high heart rates
(.100 b.p.m.), with individually adapted pitch values for heart rates
.40 and ,100 b.p.m. Each tube provided 412 mA/rot (625 mA),
and full X-ray tube current (100%) was given during the 14–46% of
the R–R interval. The scan ranged from the top of the aortic arch
to the diaphragm. The volume of iodinated contrast material (Visipa-
quew 320 mg/mL, GE Health Care, Eindhoven, The Netherlands)
was adapted to the expected scan time. A contrast bolus (50–
60 mL) was injected in an antecubital vein at a flow rate of 5.0 mL/s
Figure 1 Definition of cut planes on MSCT. The three cut planes (coronal, sagittal, and axial to the body) are first centred on the aortic valve
by clicking on it. The coronal (B) and then sagittal (A) cut planes are adjusted to obtain three orthogonal planes through the aortic root were the
nadir of each of the three aortic leaflets could be seen simultaneously in one axial image (orange arrows, D). Annulus measurements (minimum
and maximum) were made on the axial image (D). The red and green lines represent the oblique sagittal (A) and oblique coronal planes (B),
respectively, as defined using the coapation line between the left and non-coronary cusps (C). The black lines represent the closest planes to
true coronal and sagital on the axial image (D). The yellow lines indicate where the minimum and maximum diameters were measured in this
patient (D). In the majority of patients, the minimum and maximum diameters were obtained along the red and green lines. The median (IQ
range) X-ray gantry angulation for the oblique coronal view was LAO 48 (RAO 4 to LAO 14), caudal 108 (caudal 16 to cranial 1), whereas in the
proportion of patients where the maximum diameter was at a different angulation this was obtained at median (IQ range) LAO 268 (LAO 15 to
31), cranial 98 (1–23). The oblique coronal plane (green line) is the view used for fluoroscopic guidance during PAVR procedures (E).
C.J. Schultz et al.
by guest on June 8, 2015
followed by a second contrast bolus of 30–40 at 3.0 mL/s. Bolus track-
ing was used to synchronize contrast opacification of the aortic root
with the start of the scan. End-systolic datasets were reconstructed
using a single-segmental reconstruction algorithm: slice thickness
1.5 mm; increment 0.4 mm; medium-to-smooth convolution kernel
(B26f) resulting in a spatial resolution of 0.6–0.7 mm in-plane and
0.4–0.5 mm through-plane, and a temporal resolution of 83 ms. The
radiation dose for each scan ranged from 8 to 20 mSv depending on
body habitus and table speed (slower table speed at lower heart
rates increases radiation dose).
Definitions of the axial plane of the valve and
the optimal gantry angulation for fluoroscopy
Analyses of MSCT datasets were performed on dedicated worksta-
tions using Siemens Circulation software. Axial cuts through the
aortic root were obtained by aligning the three perpendicular analysis
windows (one axial and two longitudinal, respectively, oblique sagittal
and oblique coronal), so that the most caudal attachments of all three
aortic leaflets could be seen simultaneously in one axial image
(Figure 1). The oblique sagittal plane was then modified by defining it
in the axial window at the level of leaflet coaptation as the line
running through the commissure and along the coaptation line of
the left and non-coronary leaflets thereby dividing the right coronary
sinus into visually equal halves. The oblique coronal plane (similar to
the AP view on fluoroscopy) was defined as the line orthogonal to
and crossing the oblique sagittal plane at the point of central leaflet
coaptation (i.e. the point where all three leaflets meet). Subsequently,
measurements of the root were performed at various levels on the
appropriate axial slices (Figure 1). This definition of the viewing
planes was used because the oblique coronal plane then gives the
angulation of the X-ray gantry that is used to guide CRS positioning
during PAVR procedures, i.e. the ‘implanter’s view’ (Figure 1E).
Definition of the base of the leaflets (annulus)
and measurements of interest
The aortic annulus or base of the native leaflets was defined as the
axial plane where the most caudal attachment of all three aortic leaf-
lets could be seen simultaneously, (Figure 1D). The smallest (Dmin) and
largest (Dmax) orthogonal diameters were measured on the axial image
at this level. In the majority of patients, Dminand Dmaxwere found par-
allel to the oblique sagittal and oblique coronal planes (Figure 1).
The oblique sagittal plane approximates the parasternal long-axis
view on TTE and the mid-oesophageal long-axis view on TEE and
usually provides the smallest diameter (Dmin).13,18This view corre-
sponds with the manufacturer’s guideline of sizing. The oblique
cine-angiography (implanter’s view) and usually provides the largest
In addition to Dminand Dmax, the annulus luminal circumference
(circ) and cross-sectional surface area (CSA) were measured from
which the mean diameters (Dcirc, DCSA) were derived from equations:
Dcirc¼ circ/p and DCSA¼20 ? square root (CSA/p).
Variables are given as the mean and standard deviation (SD) or, if the
distribution was not Gaussian, as the median and interquartile range
(IQ range). The different diameter measurements were all normally
distributed and were compared in the same patient using the
Student t-test for paired data. Statistical analysis was done using SPSS
16.0. Statistical significance was defined as P , 0.05.
The baseline characteristics of the total study population are
shown in Table 1.
Annulus size; distribution of different
The minimum axial diameter of the aortic root was found along the
oblique sagittal plane, which ran along the coaptation line of the
non- and left coronary cusps, with the maximum diameter orthog-
onal to it in the oblique coronal plane in 68% of cases. In 32% of
patients, the minimum and maximum diameters were in different
orientations on the axial window (Figure 1). In this patient
subset, the X-ray gantry angulation required for obtaining Dmax
was significantly greater than for the implanter’s view: median
(IQ range) left anterior oblique (LAO) 268 (LAO 15–31), cranial
98 (1–23) vs. LAO 48 (RAO 4 to LAO 14), caudal 108 (caudal
16 to cranial 1) (Figure 1).
The annulus diameters obtained from the various measurements
and calculations are shown in Table 2. Substantial differences were
seen between the Dminand Dmax(mean difference 6.5 mm, 95% CI
of the difference 5.7–7.2, P , 0.001). The summarized diameter
measurements Dmean, Dcirc, and DCSAall lay in between Dminand
Dmax,but Dcircwas significantly larger than DCSAor Dmeanby 0.6
and 0.8 mm, respectively, on average (both P , 0.01).
Gender (% male)
Stroke/TIA, n (%)
LV FVT normal
Characteristic Mean (SD) or median
TIA, transient ischaemic attack; AMI, acute myocardial infarction; CABG, coronary
artery bypass surgery; PCI, percutaneous coronary intervention; PVD, peripheral
vascular disease; LV, left ventricle.
Application of sizing guidelines to MSCT measurements
by guest on June 8, 2015
In the 50 patients who subsequently received a CRS, the annulus
diameter measured on TTE (parasternal long-axis view) was
22.7 mm (2.2) and lay between Dminand DCSA[mean (SD) 21.5
(2.8) and 24.0 (2.7), respectively].
Sizing based on different annulus
The CRS size selection based on the application of industry guide-
lines (26 mm CRS: 20–23 mm annulus; 29 mm CRS: 23–27 mm
annulus) to the different estimations of annulus diameter are
shown in Table 3.
If Dminwere used for sizing, 74% of the patients would be eligible
for CRS implantation (48% for a 26 mm CRS, 12% for a 29 mm
CRS, and 14% for either a 26 mm or a 29 mm CRS given the
overlap in the manufacturer’s guidelines). Yet, 26% of the patients
would be ineligible for CRS implantation (annulus too small in 23%
and too large in 3%).
If Dmaxwere used, 61% of the patients would be eligible for CRS
implantation (4% for a 26 mm CRS, 52% for a 29 mm CRS, and 5%
would receive either a 26 mm or a 29 mm CRS) and 39% would
not be eligible for a CRS implantation because of too large an
annulus in all.
If DmeanDcirc, or DCSAwere used the majority of patients would
be eligible for a 29 mm CRS and 11, 16, and 9%, respectively,
would not be eligible because of too large an annulus in all.
Retrospective comparison of sizing based
on the application of industry guidelines to
different multislice computer tomography
annulus diameter measurements with the
operator choice of CRS size in 50 patients
in whom a CRS was implanted
Sizing based on Dmincorresponded to operator choice in 44% of
patients but would have led to a smaller prosthesis than was
selected by the operator in a 26%, whereas a further 24% would
not have been eligible for a CRS due to too small an annulus
(Figure 2). Sizing based on Dmax corresponded to operator
choice in 30% but would have led to the selection of a larger pros-
thesis in 32%, whereas a further 36% of patients would not have
been eligible for a CRS due to too large an annulus. Sizing based
on the mean diameters Dmeanand DCSAcorresponded best with
operator choice (in 74% and 76%, respectively), whereas sizing
based on Dcirccorresponded in only 60%.
Minimum (Dmin) 21.4 (2.8)
Distribution of different annulus measurements
Measured or derived MSCT annulus diameterAll patients (n 5 75)Patients with CRS (n 5 50)
Maximum (Dmax)26.9 (2.8)26.7 (2.9)
Mean (Dmean) 24.1 (2.6)24.0 (2.7)
‘Mean’ from circumference (Dcirc)24.3 (2.1)25.0 (2.7)
‘Mean’ from CSA (DCSA) 23.6 (2.0)24.0 (2.6)
All measures are expressed as mean (SD) in mm, CSA, cross-sectional surface area.
C.J. Schultz et al.
by guest on June 8, 2015
Eligible for CRS (%)26 mm (%)29 mm (%)
measured or derived from multislice computer tomography
Eligibility of percutaneous aortic valve replacement based upon on different annulus dimensions either
MSCT annulus measurement (n 5 75)Annulus suitable for CRS with inflow
26 or 29 mm (%)Not eligible for CRS (%)
Manufacturer: 26 mm CRS: 20–23 mm annulus; 29 mm CRS: 23–27 mm).
aAnnulus too small in 23%.
bAnnulus too big in 40%.
cAnnulus too big in 11%.
dAnnulus too big in 16%.
eAnnulus too big in 9%.
Figure 2 Comparison of proposed CRS size selection based on different annulus diameter measurements (manufacturer’s guidelines: 26 mm;
CRS: 20–23 mm annulus; 29 mm CRS: 23–27 mm annulus) with operator choice in 50 patients in whom a CRS was implanted.
Application of sizing guidelines to MSCT measurements
by guest on June 8, 2015
In patients where oversizing was evident the majority had
received a small (26 mm) CRS, whereas in patients where under-
sizing was evident the majority had received a large (29 mm) CRS.
Evaluation of a potential adverse
procedural outcome associated with a
discrepancy in sizing between the
application of current industry guidelines
to different multislice computer
tomography annulus diameters and the
implanted prosthesis size (operator
There were no cases of unexplained device embolization and
aortic root rupture occurred in one patient after predilatation.
The odds of an adverse procedural outcome (aortic regurgitation
greater than Grade 2, unexplained device embolization, or aortic
root rupture) associated with a discrepancy in size selection
between the application of current industry guidelines for sizing
to different MSCT annulus diameters and the implanted prosthesis
size (operator choice) were calculated for each of the MSCT
annulus diameters (Table 4). A trend was seen towards a higher
risk of adverse events when operator choice of valve size disagreed
with the aggregate diameter measurements (Dmean, Dcirc,DCSA),
but none of the odds ratios were statistically significant and confi-
dence intervals were wide (Table 4).
The present study shows that incorrect valve sizing based on the
application of industry guidelines to different annulus diameter
measurements is a frequent occurrence. Incorrect sizing was
least frequent (but still present in 24% of patients) when industry
guidelines were applied to the mean diameter calculated from the
annulus CSA (DCSA). Measurement of the annulus CSA is not men-
tioned in current guidelines and cannot be measured accurately
using 2D TTE, the most commonly used imaging modality. The
Dmeancalculated from the minimum and maximum annulus diam-
eters gave a very similar prevalence of incorrect sizing (26%) to
DCSA, but again are ideally measured on axial images, which may
not be obtainable by 2D TTE. Industry guidelines are based on
an idealized symmetrical aortic root, whereas in the present
study the annulus was non-circular and often oval similar to
other the findings of studies using 3D imaging modalities including
64-slice MSCT, 3D TTE, or cardiac magnetic resonance imaging
(CMRI).13–17We defined the annulus as a virtual ‘ring’ with
three anatomical anchor points at the nadir of each the three
aortic cusps. This definition of the annulus on MSCT is in
keeping with the anatomical definition, but has not been used by
other 3D imaging studies.6Possibly the nadir of the cusps are
more readily discernable with dual source MSCT due to improved
temporal resolution compared with 64-slice MSCT and improved
spatial resolution compared with CMRI or 3D TTE.
We observed that sizing based on Dmeanand DCSAalso corre-
sponded best to operator choice, whereas based on Dmin or
Dmax0–50% of the patients received a CRS that was too large
and 22–38% of the patients received a CRS that was too small.
Although, based on DCSA,10 patients received undersized CRS,
it has to be borne in mind that 4 of 10 were implanted before
October 2007 when the size 29 CRS first became available. Fur-
thermore, the modality used most often for sizing remains TTE,
usually on the parasternal long-axis view. This measurement
would correspond most closely with Dminon MSCT. In addition,
both TTE and TOE tend to underestimate the diameter compared
with surgical sizing or MSCT by 1–2 mm on average, most
likely due to the difficulty in defining a measurement that cuts
through the true centre of the annulus on 2D images.11–13,18As
a result, one might anticipate a higher prevalence of undersizing
that was observed in this retrospective study. Other factors
apart from TTE measurements must have influenced the sizing
decision such as clinical variables (height and weight) or procedural
factors such as the expansion size/pressure of the pre-dilatation
On the basis of the observations from this study and the recog-
nition that TTE and TOE remain the imaging modalities used most
frequently for sizing, we anticipate that undersizing will also be
common in other populations. This would seem to be supported
by a number of case reports of unexpected device emboliza-
tion.19–21In our series, none of the valves embolized despite
undersizing, which suggests that the CRS is anchored at the level
of the calcified native leaflets in addition to (good) apposition in
the LVOT. An interesting observation is that of apparently success-
ful implantation procedures despite that one or even both annulus
diameters on MSCT do not comply with industry guidelines on
sizing. This observation indicates that how the CRS anchors and
Odds of adverse outcome when operator
choice disagreed (95% CI)
Odds of an adverse outcome
Different annulus diameters from MSCT used for sizing by application of current industry
0.90 (0.29–2.77)1.02 (0.31–3.36) 1.71 (0.48–6.10)1.50 (0.48–4.60)1.38 (0.37–5.06)
Aortic regurgitation higher than Grade 2, unexplained device embolization (occurred in two patients due to operator error was not included) or aortic root rupture (occurred in
one patient after predilatation) when there was a discrepancy between sizing by applying current industry guidelines to different multislice computer tomography diameters and
operator choice. CI, confidence interval; MSCT, multislice computer tomography.
C.J. Schultz et al.
by guest on June 8, 2015
seals in the LVOT in some patients are not yet fully understood,
but also that prospective studies are required to evaluate the
medium to long-term effects of patient to prosthesis mismatch fol-
lowing PAVR. There are no published data on sizing in PAVR. Sub-
optimal sizing of a surgically implanted prosthesis is associated with
a reduced prognosis.22,23Although the surgically implanted pros-
thesis is sewn in place the PAVR prosthesis relies on good sizing
and apposition to maintain both position in the LVOT and func-
tional integrity. One might therefore expect an important physio-
logical effect of sub-optimal sizing on outcome following PAVR,
although it is possible that in the aged, frail, and comorbid patients
who receive PAVR the prognostic effect would be minimal. Fur-
thermore, compression of the semi-rigid circular frame of the
CRS inflow in one plane (diameter) may lead to some expansion
in the orthogonal plane (diameter) leading to an elliptical shape,
because within the constraints of the design the CRS inflow may
conform to an elliptical annulus apparently without adverse
effect.24It would therefore also seem reasonable to suggest
using DCSAor Dmeanas the diameter of choice for sizing decisions.
However, further studies are required and possibly the construc-
tion of patient customized valve frames should be considered.
In the present study, the relatively large differences between the
minimum and maximum diameters of the annulus (mean 6.5 mm)
had a substantial effect on hypothetical sizing. If the minimum diam-
eter was used the majority of patients would either receive a
26 mm inflow CRS or not be eligible due to too small an
annulus. On the other hand, if the largest diameter were used
for sizing the majority of patients would receive a 29 mm inflow
CRS or not be eligible due to too large an annulus. There is the
potential for substantial variability between operators/institutions
in CRS size selection depending on the preferred imaging modality.
It is not known whether any particular diameter measurement
should be given more weight when sizing or is more likely to
give a good long-term outcome if considered above other
measurements. These observations underscore the need for a
scientific basis for sizing, which at present is lacking. In the
absence of such substantiation, the availability of more valve
sizes may increase the likelihood of a better prosthesis-host
match, but would also increase the risk of adverse events in case
of a substantial mismatch, due to the larger size difference
between the smallest and largest prosthesis. Others have demon-
strated the importance of accurate sizing to patient safety, acute
and long-term valve function.19–21,25–27
The present study is retrospective and the findings should be
viewed as hypothesis generating. The study shows that the issue
of sizing is far more complex than current industry guidelines
would suggest but more detailed studies are required to under-
stand how to optimally size followed by prospective validation
studies. Only one 3D imaging modality (MSCT) was used for the
evaluation of the non-circular annulus. Although other 3D
imaging modalities such as 3D echocardiography and MRI also
allow appreciation of the 3D anatomy of the aortic root these
have other limitations and further studies are needed to evaluate
the applicability for sizing. We believe that MSCT is the modality
of choice for evaluation of patient anatomy before PAVR, but
comparisons with other 3D modalities and the 2D modalities of
TTE and TEE are needed to establish a gold standard for the
measurement of annulus diameter.28The absence of a significant
association between apparently incorrect sizing and aortic regurgi-
tation reflects the multiple potential causes of AR (including incor-
rect implantation depth, prevention of apposition, or perforation
of the pericardial skirt by calcium among others) in addition to
incorrect sizing, but may also be the result of the relatively small
number of patients studied.
The aortic annulus is often elliptical and differences in the
minimum and maximum diameter can lead to substantial differ-
ences in the selection of prosthesis size, which may result in under-
sizing or oversizing. If DCSAwere to be used for sizing only 11% of
patients referred for PAVR would not be eligible for either a
26 mm or a 29 mm inflow CRS. Undersizing during PAVR based
on current guidelines is likely to be common and may affect all
prosthesis types. Industry guidelines for sizing should recognize
that the aortic annulus is oval in shape. Our data show that
using DCSAor Dmeanmay improve sizing and reduce both over-
and undersizing, but further studies are required.
The authors acknowledge the invaluable help of Marcel Dijk-
shoorn, Specialist research technician MSCT, with optimizing scan-
ning protocols and imaging reconstruction.
Conflict of interest: none declared.
1. Lund O, Nielsen TT, Emmertsen K, Flø C, Rasmussen B, Jensen FT, Pilegaard HK,
Kristensen LH, Hansen OK. Mortality and worsening of prognostic profile during
waiting time for valve replacement in aortic stenosis. Thorac Cardiovasc Surg 1996;
2. Vahanian A, Alfieri O, Al-Attar N, Antunes M, Bax J, Cormier B, Cribier A, De
Jaegere P, Fournial G, Kappetein AP, Kovac J, Ludgate S, Maisano F, Moat N,
Mohr F, Nataf P, Pie ´rard L, Pomar JL, Schofer J, Tornos P, Tuzcu M, van
Hout B, Von Segesser LK, Walther T, European Association of Cardio-Thoracic
Surgery. European Society of Cardiology; European Association of Percutaneous
Cardiovascular Interventions.Transcatheter valve implantation for patients with
aortic stenosis: a position statement from the European Association of
Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology
(ESC), in collaboration with the European Association of Percutaneous Cardio-
vascular Interventions (EAPCI). Eur Heart J 2008;29:1463–1470.
3. Pellikka PA, Sarano ME, Nishimura RA, Malouf JF, Bailey KR, Scott CG, Barnes ME,
Tajik AJ. Outcome of 622 adults with asymptomatic, hemodynamically significant
aortic stenosis during prolonged follow-up. Circulation 2005;111:3290–3295.
4. Charlson E, Legedza AT, Hamel MB. Decision-making and outcomes in severe
symptomatic aortic stenosis. J Heart Valve Dis 2006;15:312–321.
5. Otten A, van Domburg R, van Gameren M, Kappetein AP, Takkenberg J,
Bogers A, Serruys PW, de Jaegere P. Population characteristics, treatment assign-
ment and survival of patients with aortic stenosis referred for percutaneous valve
replacement. EuroInterv 2008;4:250–255.
6. Piazza N, Grube E, Gerckens U, den Heijer P, Linke A, Luha O, Ramondo A,
Ussia G, Wenaweser P, Windecker S, Laborde J-C, de Jaegere P, Serruys PW
on behalf of the clinical centres who actively participated in the registry. Pro-
cedural and 30-day outcomes following transcatheter aortic valve implantation
using the third generation (18 Fr) CoreValve ReValving System: results from
the multicentre, expanded evaluation registry 1-year following CE mark approval.
7. Grube E, Laborde JC, Gerckens U, Felderhoff T, Sauren B, Buellesfeld L,
Mueller R, Menichelli M, Schmidt T, Zickmann B, Iversen S, Stone GW. Percuta-
neous implantation of the CoreValve self-expanding valve prosthesis in high-risk
Application of sizing guidelines to MSCT measurements
by guest on June 8, 2015
patients with aortic valve disease: the Siegburg first-in-man study. Circulation 2006; Download full-text
8. Cribier A, Eltchaninoff H, Tron C, Bauer F, Agatiello C, Sebagh L, Bash A,
Nusimovici D, Litzler PY, Bessou JP, Leon MB. Early experience with percuta-
neous transcatheter implantation of heart valve prosthesis for the treatment of
end-stage inoperable patients with calcific aortic stenosis. J Am Coll Cardiol
9. Webb JG, Pasupati S, Humphries K, Thompson C, Altwegg L, Moss R, Sinhal A,
Carere RG, Munt B, Ricci D, Ye J, Cheung A, Lichtenstein SV. Percutaneous trans-
arterial aortic valve replacement in selected high-high-risk patients with aortic ste-
nosis. Circulation 2007;116:755–763.
10. Piazza N, de Jaegere P, Schultz C, Becker P, Serruys PWJS, Anderson R. Anatomy
of the aortic valvar complex and its implications for transcatheter implantation of
the aortic valve. Circ Cardiovasc Intervent 2008;1:74–81.
11. Babaliaros V, Liff D, Chen E, Rogers J, Brown R, Thourani V, Guyton R, Lerakis S,
Stillman A, Raggi P, Cheesborough J, Veladar E, Green J, Block P. Can balloon
aortic valvuloplasty help determine appropriate transcatheter aortic valve size?
J Am Coll Cardiol Intv 2008;1:580–586.
12. Alkadhi H, Desbiolles L, Husmann L, Plass A, Leschka S, Scheffel H, Vachenauer R,
Schepis T, Gaemperli O, Flohr TG, Genoni M, Marincek B, Jenni R, Kaufmann PA,
Frauenfelder T. Radiology 2007;245:111–121. Aortic regurgitation: assessment
with 64-section CT.
13. Tops LF, Wood DA, Delgado V, Schuijf JD, Mayo JR, Pasupati S, Lamers FPL, van
der Wall EE, Schalij MJ, Webb JG, Bax JJ. Noninvasive evaluation of the aortic root
with multislice computed tomography: implications for transcatheter aortic valve
replacement. J Am Coll Cardiol Imaging 2008;1:321–330.
14. Doddamani S, Grushko MJ, Makaryus AN, Jain VR, Bello R, Friedman MA,
Ostfeld RJ, Malhotra D, Boxt LM, Haramati L, Spevack DM. Demonstration of
left ventricular outflow tract eccentricity by 64-slice multi-detector CT. Int J
Cardiovasc Imaging 2009;25:175–181.
15. Doddamani S, Bello R, Friedman MA, Banerjee A, Bowers JH Jr, Kim B,
Vennalaganti PR, Ostfeld RJ, Gordon GM, Malhotra D, Spevack DM. Demon-
stration of left ventricular outflow tract eccentricity by real time 3D echocardio-
graphy: implications for the determination of aortic valve area. Echocardiography
16. Tanaka K, Makaryus AN, Wolff SD. Correlation of aortic valve area obtained by
the velocity-encoded phase contrast continuity method to direct planimetry using
cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2007;9:799–805.
17. Willmann JK, Weishaupt D, Lachat M, Kobza R, Roos JE, Seifert B, Lu ¨scher TF,
Marincek B, Hilfiker PR. Electrocardiographically gated multi-detector row CT
for assessment of valvular morphology and calcification in aortic stenosis.
18. Wood DA, Tops LF, Mayo JR, Pasupati S, Schalij MJ, Humphries K, Lee M, Al Ali A,
Munt B, Moss R, Thompson CR, Bax JJ, Webb JG. Role of multislice computed
tomography in transcatheter aortic valve replacement. Am J Cardiol 2009;103:
19. Webb JG, Chandavimol M, Thompson CR, Ricci DR, Carere RG, Munt BI,
Buller CE, Pasupati S, Lichtenstein S. Percutaneous aortic valve implantation
retrograde from the femoral artery. Circulation 2006;113:842–850.
20. Cribier A, Eltchaninoff H, Tron C, Bauer F, Agatiello C, Nercolini D, Tapiero S,
Litzler PY, Bessou JP, Babaliaros V. Treatment of calcific aortic stenosis with
the percutaneous heart valve: mid-term follow-up from the initial feasibility
studies: the French experience. J Am Coll Cardiol 2006;47:1214–1223.
21. Clavel MA, Dumont E, Pibarot P, Doyle D, De Larochellie `re R, Villeneuve J,
Bergeron S, Couture C, Rode ´s-Cabau J. Severe valvular regurgitation and late
prosthesis embolization after percutaneous aortic valve implantation. Ann
Thorac Surg 2009;87:618–621.
22. Yankah AC, Klose H, Musci M, Siniawski H, Hetzer R. Geometric mismatch
between homograft (allograft) and native aortic root: a 14-year clinical experi-
ence. Eur J Cardiothorac Surg 2001;20:835–841.
23. Kulik A, Burwash IG, Kapila V, Mesana TG, Ruel M. Long-term outcomes after
valve replacement for low-gradient aortic stenosis: impact of prosthesis-patient
mismatch. Circulation 2006;114:I553–I558.
24. Schultz CJ, Weustink A, Piazza N, Otten A, Mollet N, Krestin G, van Geuns RJ,
de Feyter P, Serruys PWJ, de Jaegere P. Geometry and degree of apposition of
the CoreValve Revalving System (CRSw) with multislice computer tomography
after implantation in patients with aortic stenosis. J Am Coll Cardiol 2009;54:
25. Zegdi R, Ciobotaru V, Noghin M, Sleilaty G, Lafont A, Latre ´mouille C, Deloche A,
Fabiani JN. Is it reasonable to treat all calcified stenotic aortic valves with a valved
stent? Results from a human anatomic study in adults. J Am Coll Cardiol 2008;51:
26. Thubrikar M, Piepgrass WC, Shaner TW, Nolan SP. The design of the normal
aortic valve. Am J Physiol 1981;241:H795–H801.
27. Thubrikar M, Piepgrass WC, Deck JD, Nolan SP. Stresses of natural versus pros-
thetic aortic valve leaflets in vivo. Ann Thorac Surg 1980;30:230–239.
28. Moss RR, Ivens E, Pasupati S, Humphries K, Thompson CR, Munt B, Sinhal A,
Webb JG. Role of echocardiography in percutaneous aortic valve implantation.
JACC Cardiovasc Imaging 2008;1:15–24.
C.J. Schultz et al.
by guest on June 8, 2015