Peter Hansen is a Cardiologist with a particular interest in Transcatheter Aortic Valve Implantation. This talk is all about TAVI's and imaging used to assess them. You may be seeing a lot more TAVI's so this superb insight from an expert is invaluable.
2. Use of Imaging for TAVI
§ Assessment pre TAVI
§ TTE, MSCT, 3DE, coronary angiography
§ Assessment during TAVI
§ TOE/TTE, Fluroscopy
§ Assessment post TAVI
§ TTE, MSCT
5. Is
it
severe
AS?
• “Flow dependent” parameters
• Post-VPC accentuation of gradient
• Atrial fibrillation
• Aortic regurgitation
• “Classical” LG LF severe AS reduced
LVEF (DSE)
• “Paradoxical” LG LF severe AS normal
LVEF
• NF, LG, N LVEF severe AS
9. Dobutamine
stress
ECHO
in
paFent
with
LGSAS
Baseline
CW
tracing:
Peak
velocity
3.2
m/s
Mean
grad
25
mmHg
AVA
0.45
cm2
CW
10ug/kg/min
dobutamine
Peak
velocity
4.1
m/s
Mean
grad
39
mmHg
AVA
0.5
cm2
10. DSE in a patient with Pseudo-severe AS
Baseline
5
ug/kg/min
Peak
velocity
stable,
AVA
increased,
contracFle
reserve
+,
absence
of
severe
AS
10
ug/kg/min
20
ug/kg/miin
11. NFHG
N
EF
LFLG
N
EF
NFLG
N
EF
LFLG
Low
EF
Algorithm
for
classificaFon
of
paFents
with
LGSAS
MSCT
–
extent
of
AV
calcium
14. Understanding Annulus Anatomy
VIRTUAL
ANNULUS
Most basal point of aortic leaflet attachment
Measured during systole, ensure alignment,
Circ
Cardiovasc
Interv:
2008
Piazza
et
al
trailing edge to leading edge – PLAX TTE/TOE
15. MSCT
ECHO
3D
2D
AorFc
annulus
is
oval
In
shape
in
majority
of
PaFents
RaFo
of
longD/shortD
1.28
16.
17. Basal SAX view of Aortic Valve
RC
LC
NC
Circ
Cardiovasc
Interv:
2008
Piazza
et
al
44. When should 3DE be a surrogate,
alternative or preferred for TAVI sizing
• When MSCT cannot be obtained but 3D available
– No local expertise with MSCT
• When MSCT is contraindicated/risky
– Severe renal impairment
• When there is doubt regarding the quality of the
MSCT
– Motion artifact/difficult to repeat
47. MSCT
GOLD
STANDARD
FOR
AORTIC
ANNULUS
SIZING
2D
TEE
AND
TTE
UNDERESTIMATES
AORTIC
ANNULUS
DIMENSIONS
AORTIC
ANNULUS
DIMENSIONS
IMPORTANT
FOR
ACCURATE
PROSTHESIS
SIZING
67. Procedural Findings
Assessment
of
Post-‐Procedural
AR:
Requires
agreement
of
three
assessment
tools
Echocardiography
Hemodynamics
Aortography
PVAR
vs
VAR
Severity
ComplicaFons
AR
Valve
posiFon
Gradient/AVI
Coronary
perfusion
TCT 2013 Procedural Outcomes Extreme Risk Study | Iliofemoral Pivotal 67
68. Cath
Lab
Assessment
Immediate
Post
Deployment
• Haemodynamic
– AV
index:
Ao
diastolic
pressure-‐LVEDP
(<25
=
significant
AR)
– Peak
to
Peak
gradient
+
mean
gradient
(PT
Ao-‐LVPT)
• Aortography
– PVAR/VAR
–
use
enough
contrast/RAO
projecFon
– Coronary
artery
perfusion
– Competence
of
aorFc
root
• ECHO:
TOE/TTE
– AorFc
paravalvular
and
valvular
leak
– Systolic
valve
funcFon:
PG,
MG,
AVA
– LV/RV
systolic
funcFon
– Pericardial
effusion
–
compare
with
baseline
– Mitral
valve
funcFon
–
mitral
regurgitaFon,
AML
hinge
point
– Tricuspid
valve/pulmonary
pressure
69. ComplicaFons
&
Management
AorFc
RegurgitaFon
• Typically paravalvular mild
or mild-moderate severity
• Most of AR disappears or
reduces at 1 yr follow-up
[13% absent, 80% mild AR]
Cardiol
Clin
29
(2011)
211–222
J.
Am.
Coll.
Cardiol.
2012;59;1200-‐1254
78. Assessment
of
para-‐valvular
aorFc
regurgitaFon
post
TAVI
**
Not
well-‐validated
and
may
overesFmate
the
severity
compared
with
the
quanFtaFve
doppler
PVAR
assessment
cont’d……..
TOE:
Deep
transgastric
permits
best
axial
alignment
for
the
quanFtaFve
doppler
measurement
of
regurgitant
pressure
half-‐Ame.
PLAX
and
PSAX
ME:
indenFficaFon
of
site,
number
and
extent
of
PVAR
jets.
Vena
contracta
diameter
and
area
can
be
assessed
using
2D
and
3D
colour
doppler
but
may
not
be
a
reliable
measure
of
PVAR
post
TAVI
(mulFple,
small,
irregular
shape,
eccentric
jets)
92. Suggested time for routine ECHO
follow up post TAVI
§ 24-48 hrs, pre-discharge
§ 30 days
§ 6 month
§ 12 months
§ Then yearly thereafter
93. Routine ECHO assessment of
TAVI valve
• Valve position
• Valve morphology
• Valve function
– Systolic
– Diastolic
• LV size and systolic function +RV
• Mitral + tricuspid
• Pulmonary pressure
• Pericardial effusion
94. How is TAVI different from SAVR
• TAVI (vs SAVR)
– No sewing ring
– Much longer prosthesis (up to 55 mm)
• Flow acceleration
• LVOT diameter
• Valve type
• PVAR
– Native valve in situ
• Calcium, leaflets, prosthesis type, size, expansion
– LBBB more common
95. Definition of new valve dysfunction at
follow-up
• Suspected structural TAVI failure: compare to patient’s
baseline ECHO eg TTE post-procedure (Day 1)
• Significant changes:
– An increase in the mean gradient >10 mmHg
– A decrease in the AVA >0.3-0.4 cm2
– A reduction in the DVI >0.10-0.13
• Exclude measurement error –
– Baseline (Day 1) LVOT diameter
– Depends on valve depth in LVOT and valve type
– LVOT diameter and LVOT velocity for AVA should be measured in same
location outside the stent frame
– LVOT non-circular
– Flow acceleration inside stent frame prox to valve cusps with elevated
velocity
• Note changes in LV function and allow for effect on gradient
96. Definition of new valve dysfunction at
follow-up
• Suspected structural TAVI failure: compare
to patient’s baseline ECHO eg TTE post-procedure
(Day 1)
• Significant changes:
– An increase in the mean gradient >10 mmHg
– A decrease in the AVA >0.3-0.4 cm2
– A reduction in the DVI >0.10-0.13
98. Post-implantation follow up of
TAVI patients
• Similar to follow up of surgically implanted
prostheses but two important differences
– Calculation of EOA as an index of valve opening:
• Founded in ratio of post- to pre-valvular velocities
• Flow acceleration within transcatheter valve proximal to
the valve cusps
• Pre-valvular velocity should be recorded proximal to the
stent (PW doppler with sample situated where LVOT
diameter measured) and the post-valvular velocity
recorded with CW doppler reflects that distal to the
stented valve
• If the LVOT velocity used in the calculations is
erroneously recorded inside the stent but proximal to the
cusps the result will be an increased velocity with an
overestimation of the valve area and DVI
99. Prosthetic Aortic Stenosis
• Limitation of flow independent parameters
– The absolute EOA does not account for the cardiac output
requirements in relation to the patients body size
– The indexed EOA may overestimate the haemodynamic burden in
obesity; hence lower criteria may be more appropriate in patients
with a BMI>30kg/m2
– DVI severity criteria are dependent on LVOT size ie a lower
threshold may be more appropriate if LVOT>25mm
– The LVOT should be measured just beneath the ventricular margin
of the valve stent/skirt
– Unlike the surgically implanted valve, the transcatheter prosthetic
valve EOA is defined not only by the size of the valve but also by
the patient’s aortic valve/annular anatomy and procedural variables.
Thus, well-established normal trans- catheter valve gradients and
EOAs based on preimplant aortic annular dimensions do not
currently exist.
105. Assessment
of
para-‐valvular
and
valvular
prostheFc
AR
post
TAVI
**
Not well-validated, assumes continuity of flow and may overestimate the severity
compared with the quantitative doppler
PLAX
and
PSAX
TTE:
Number/distribution and extent of PVAR jets. A3C and A5C for
further assessment of jets: PHT.
106. MSCT
post
TAVI
Coronal
Oblique
View
3D
volume
rendered
view
Medtronic
CoreValve
2
weeks
post
TAVI
-‐Adequate
deployment
-‐No
instent
restenosis
-‐Patent
coronary
art
-‐Good
valve
posiFon
-‐Integrity
of
stent
struts
-‐thrombus/vegetaFon
visible
on
leaflets
-‐Assymmetric
expansion
132. A5C
TTE
Day
2
Post
TAVI
CDF
PVAR
and
PHT
PVAR
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
143.
144.
145.
146.
147.
148.
149.
150.
151. The
color
Doppler
jet
of
a
paravalvular
leak
is
ouen
best
appreciated
from
the
deep
transgastric
TEE
view
(Figure
19).
This
view
usually
permits
the
best
axial
alignment
for
the
quanFtaFve
Doppler
measure
of
regurgitant
pressure
half-‐Fme.
The
midesophageal
views
provide
the
cross-‐
secFonal
and
long-‐
axis
views
to
facilitate
idenFficaFon
of
the
site
and
extent
of
paravalvular
leak.
The
vena
contracta
diameter
and
area
can
be
assessed
using
2D
and
3D
color
Doppler
applicaFon,
respecFvely
(Figure
20).
152. Valve
funcFon
• Valve
Academic
Research
ConsorFum-‐2
maintains
the
original
recommendaFons
to
use
echocardiography
as
the
primary
imaging
modality
for
the
assessment
of
prostheFc
valve
funcFon.39
This
should
include
the
valve
posiFon,
morphology,
funcFon,
and
evaluaFon
of
the
leu
ventricle
(LV)
and
right
ventricle
(RV)
size
and
funcFon.
The
sug-‐
gested
Fme
points
for
rouFne
follow-‐up
transthoracic
echo-‐
cardiography
(TTE)
following
valve
implantaFon
are:immediately
(before
discharge)
following
the
implantaFon
for
transarterial
approaches
or
within
30
days
for
transapi-‐
cal
or
transaorFc
approaches,
6
months
following
implantaFon,
1
year
following
implantaFon,
and
yearly
thereauer.
At
these
endpoints,
prostheFc
aorFc
valve
steno-‐
sis
and
regurgitaFon
should
be
reported.
153. Diagnosis
of
aorFc
stenosis
• Establishing
diagnosis
of
severe
AS
– AVA
<0.8-‐1.0
or
AVAI
<0.6cm/m2
– MG
>40
mmHg
– Peak
velocity
>4.0
m/s
• Pixalls
in
ECHO
diagnosis
– Gradient
post-‐ectopic
– Hyperdynamic
states
eg
anaemia
– AorFc
regurgitaFon
– Doppler
beam
not
parallel
to
valve
being
assessed
– Low
LVEF
“classical”
LF
LG
severe
AS
(DSE
of
use):
severe
vs
pseudosevere
AS
and
contracFle
reserve
– Normal
LVEF
“paradoxical”
LF
LG
severe
AS:
hypertrophied
low
volume
LV,
low
SV
154. • TTE
(pre-‐TAVI
planning)
– Annular
dimension
for
accurate
valve
sizing
• LimitaFons
of
TTE
and
TOE
• TAVI
CT
method
of
choice
• Undersizing
may
cause
PVL,
valve
migraFon
• Oversizing
may
cause
root
rupture
and
incomplete
expansion
of
valve
leaflets
with
valvular
AR,
reducFon
in
valve
durability
• Annular
diameter
measure
in
systole
(annulus
is
bigger
in
systole),
in
PSLAX,
at
point
of
inserFon
of
aorFc
cusps
(virtual
annulus),
from
Fssue
blood
interface
to
Fssue
blood
interface:
trailing
edge
to
leading
edge
• TTE
underesFmates
the
annulus
in
most
cases
(not
measuring
true
diameter,
annulus
no
circular
but
oval
in
most
cases)
• TOE
2D
sFll
underesFmates
annulus
in
30%
of
cases,
but
overesFmates
annulus
in
10-‐20%
of
cases
making
valve
sizing
difficult
• TOE
3D
is
more
accurate
and
correlates
well
with
TAVI
CT
measurements
but
resoluFon
much
lower
and
equipment
and
experience
required
to
be
useful
155. • TTE
(pre-‐TAVI
planning)
– Bicuspid
vs
tricuspid
valve
– LV
and
RV
dimensions
and
funcFon
– AorFc
regurgitaFon
– Structure
and
funcFon
of
other
valves
– LVOT
obstrucFon
– Basal
septal
hypertrophy
– LV
thrombus
– Pre-‐exisFng
echolucent
pericardial
space
eg
fluid
or
fat
and
calcificaFon
(trans-‐apical)
156. • TOE
(pre-‐TAVI
planning)
– Not
rouFnely
done
pre-‐procedure
since
rouFne
TAVI
CT
performed
– used
in
our
insFtuFon
intra-‐procedurally
(annulus
measurements
confirmed)
– If
doubt
re:
aorFc
root,
annular
size,
bicuspid
vs
tricuspid,
LVOT
calc
– TOE
assumes
annular
circularity
–
almost
never
the
case
– Annulus
to
RCA
osFum
can
be
measured
but
not
the
annulus
to
LCA
osFum
(requires
3D-‐TOE
or
MSCT)
– AorFc
arch
atheroma
–
important
to
know
but
MSCT
also
good
and
devices
smaller
more
stearable
with
less
risk
of
embolisaFon
157. • Role
of
2D-‐ECHO
limited
during
TAVI
– Immediate
detecFon
of
complicaFons
at
any
stage
– Eg
causes
for
hypotension:
• Tamponade,
severe
PVL,
root
rupture,
new
LV
dysfuncFon
(coronary
obstrucFon)
– Assessment
of
valve
funcFon
auer
deployment
• Mechanism
of
AR
• PVL
• Valvular
regurgitaFon
• Systolic
valve
funcFon:
eg
remaining
gradient/area,
need
for
further
postdilataFon
– Deep
TG
view:
CW,
PW,
CF
• Prosthesis
impingement
of
the
AML
if
prosthesis
extends
past
the
AML
hinge
point
• Complemented
by
haemodynamic
assessment
and
aortography
158. • Role
of
3D-‐TEE
during
TAVI
– Annulus
dimension
confirmaFon
if
doubt
–
important
for
accurate
prosthesis
sizing
– Assessment
of
severity
of
PVL
post
TAVI
deployment
• Planimetry
of
regurgitant
orifice
(eg
DTG,
Mid-‐oesophageal)
• Planimetry
of
vena
contracta
– Other
imaging
modaliFes:
• Intracardiac
ECHO
(ICE)
• Trans-‐nasal
TOE
159.
160. Follow
up
assessment
• The
follow-‐up
assessment
should
also
begin
with
valve
imaging
and
documentaFon
of
changes
in
morphology.
When
determining
whether
a
paFent
has
developed
haemodynamically
significant
structural
valve
failure,
the
paFent’s
own
baseline
echocardiographic
parameters
should
be
used
as
a
reference.
• An
increase
in
the
mean
gradient
>10
mm
Hg,
a
decrease
in
the
EOA>0.3-‐0.4
cm2,
or
a
reducFon
in
the
DVI>0.1-‐0.13
probably
indicates
a
change
in
valve
funcFon
and
should
trigger
a
comprehensive
haemody-‐
namic
evaluaFon
• Whenever
valve
dysfuncFon
is
suspected,
the
careful
evaluaFon
of
valve
morphology
should
confirm
a
structurally
abnormal
valve.
In
addiFon,
measurement
error
must
be
excluded;
the
use
of
a
consistent
LVOT
diameter
for
more
accurate
follow-‐up
study
comparisons
is
recommended.
• Finally,
changes
in
ventricular
morphology
would
be
expected
in
the
se}ng
of
long-‐standing
significant
valvular
dysfuncFon
and
this
parameter
may
support
the
clinical
assessment
of
severity.
173. Key TAVI Exclusion Criteria by
ECHO
• Bicuspid or unicuspid valve
• Severe valvular regurgitation (any)
• Pre-existing prosthetic heart valve
• Moderate/severe MS
• Hypertrophic obstructive cardiomyopathy
• Severe basal septal hypertrophy with
LVOT gradient
• Aortic annulus<20 or >29 mm
• Asc aorta diameter >43 mm (>40 for small
annulus)
185. • The
immediate
post-‐TAVI
evaluaFon
documents
iniFal
valve
appearance
(posiFon
and
circularity
of
the
stent,
and
leaflet
morphology
and
moFon)
and
a
comprehensive
haemodynamic
evaluaFon.
Valve
Academic
Research
ConsorFum-‐2
advocates
using
the
integraFve
approach
• Using
1
flow
dependent
(eg,
mean
gradient)
and
1
flow
independent
criterion
(eg,
EOA)
for
the
iniFal
haemodynamic
evaluaFon
• If
there
is
discordance
between
these
measurements,
then
the
DVI
should
be
calculated.
An
abnormal
DVI
indicates
possible
prostheFc
valve
dysfuncFon
• A
normal
DVI
indicates
intrinsically
normal
prostheFc
valve
funcFon,
and
the
indexed
EOA
can
then
be
used
to
determine
the
reason
for
the
iniFal
measurement
discordance.
When
the
indexed
EOA
is
low
in
the
se}ng
of
a
normal
DVI,
the
paFent
probably
has
a
prosthesis–paFent
mismatch
(PPM),
an
indicator
of
the
intrinsic
relaFonship
of
the
implanted
valve
to
the
cardiac
output
requirements
of
the
paFent
• Prosthesis–paFent
mismatch
occurs
in
the
se}ng
of
a
morphologically
normal
valve
and
is
considered
to
be
haemodynamically
insignificant
if
the
indexed
EOA
is
>0.85
cm2/m2,
moderate
if
between
• 0.65
and
0.85
cm2/m2,
and
severe
if<0.65
cm2/m2.
However,
for
obese
paFents
(body
mass
index
>30
kg/
m2)
lower
criteria
may
be
more
appropriate
186. • There
is
growing
evidence
suggesFng
a
significant
associaFon
of
post-‐
procedural
paravalvular
aorFc
regurgitaFon
(AR)
with
short-‐
and
long-‐
term
mortality.
• As
the
number
of
implanted
transcatheter
heart
valves
increases,
valve
durability
and
dysfuncFon
become
more
crucial
issues.
• EvaluaFng
the
presence
and
severity
of
regurgitaFon
should
include
an
assessment
of
both
central
and
para-‐valvular
components,
with
a
combined
measurement
of
‘‘total’’
aorFc
regurgitaFon
(AR)
reflecFng
the
total
volume
load
imposed
on
the
LV
• The
quanFtaFve
and
semi-‐quanFtaFve
haemodynamic
assessment
of
AR
severity
should
be
performed
with
Doppler
echocardiography
according
to
the
guidelines
• Color
Doppler
evaluaFon
should
be
performed
just
below
the
valve
stent
for
para-‐valvular
jets,
and
at
the
co-‐aptaFon
point
of
the
leaflets
for
central
regurgitaFon
187. • Although
all
imaging
windows
should
be
used,
the
parasternal
short-‐axis
view
is
criFcal
in
assessing
the
number
and
severity
of
paravalvular
jets
• Whenever
possible,
the
quanFficaFon
of
the
prostheFc
regurgitant
volume,
effecFve
regurgitant
orifice
area,
and
regurgitant
fracFon
(Table
10)
should
be
performed
• The
regurgitant
volume
may
be
calculated
as
the
difference
between
the
stroke
volume
across
any
non-‐regurgitant
orifice
(RVOT
or
mitral
valve)
and
the
stroke
volume
across
the
LVOT
• It
is
important
to
realize
that
at
this
Fme
the
body
of
evidence
supporFng
the
numerical
criteria
used
in
Table
10
as
well
as
Figure
4
may
be
limited.
These
criteria
should
be
used
as
guidelines
for
clinical
decision-‐making
and
require
further
validaFon
as
our
experience
conFnues
to
expand
188. – Accurate
quanFficaFon
of
AR
post
TAVI
• May
consist
of
valvular
and
para-‐valvular
AR
(usually
just
PVR)
• Valvular
AR:
CF
doppler,
– length
of
jet
unreliable
indicator
of
severity,
– proximal
jet
width
or
cross-‐secFonal
area
preferred,
– following
criteria:
<25%
mild,
26-‐64%
moderate,
>65%
severe,
limited
to
valvular
AR
as
PVR
ouen
mulFple
jets,
irregular
shaped
jets
and
eccentric
jets
• Valvular
AR:
Vena
Contracta
– VC
esFmate
of
EROA
– AcousFc
shadowing
from
stent/sewing
ring
may
interfere
with
measurements
– VC
measured
at
the
level
of
the
cusps
of
the
bioprostheFc
valve
• QuanFtaFve
measurements
– Total
SV-‐non-‐regurgitant
valve
SV=RV
– EROA:
SV/VTI
– Based
on
several
measurements
with
potenFal
for
errors
significant
189. • Para-‐valvular
AR:
• ASE/EAE
guidelines
• Vena
Contracta
– Measured
at
the
prox
end
of
the
stent
skirt
– No
validaFon
for
adding
the
vena
contracta
of
mulFple
jets
• ProporFon
of
the
circumference
of
the
sewing
ring/proximal
stent
skirt
occupied
by
the
jet
gives
a
semi-‐quanFtaFve
guide
to
severity:
– <10%
mild
– 10-‐20%
moderate
– >20%
severe
– Assumes
conFnuity
of
the
jet
which
may
not
be
the
case
for
transcatheter
valves
and
thus
may
overesFmate
the
severity
of
PVAR
in
the
se}ng
of
mulFple
small
jets
– This
approach
does
not
consider
the
that
the
radial
extent
of
PV
jets
may
vary
(eg
surgical
PVL)
and
in
the
case
of
transcatheter
valves
may
be
very
small
ie
not
a
big
problem
– AfempFng
to
add
the
degrees
of
involvement
when
the
jets
are
small
is
challenging
• QuanFtaFve
methods
for
assessment
of
severity
of
PVAR
post
TAVI
– RV:
– comparison
of
SV
across
AV
(forward+regurg
vol)
LVOT
and
a
non-‐regurgitant
valve
eg
mitral
or
tricuspid
(RV
ouxlow),
can
be
used
for
prostheFc
valves
and
for
TAVI
– Total
stroke
volume
also
measured
by:
subtracFng
LVESV
(forward)
from
LVEDV(forward+regurgitant),
not
accurate
with
2D,
3D
may
be
the
method
of
choice,
growing
evidence
for
3D
evaluaFon
of
RV
by
this
method
for
naFve
AR
– EROA:
– Shore
pressure
half
Fme
of
CW
doppler
signal
of
AR:
problem:
mulFple
jets,
eccentric,
irregular
shape,
– Density
of
spectral
display:
best
if
one
single
jet
– Diastolic
flow
reversal
in
the
desc
aorta:
PW
doppler
from
the
suprasternal
notch/abdominal
aorta
from
subcostal
view
• CombinaFon
of
above,
iniFal
haemodynamic
assessment
and
aortography
is
ouen
required
as
well
as
clinical
parameters
during
follow
up
• CMR
auer
7
weeks
in
experienced
centres
with
the
right
magnet
is
the
most
accurate
and
limited
evidence
suggests
that
the
echo
assessment
underesFmates
the
degree
of
severity
of
PVR
post
TAVI