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22 Prosthetic Valves
Fig. 22.7 TTE image
showing
microcavitations in the
left ventricle (arrow) of
a patient with a
mechanical bileaet
prosthetic valve in the
mitral position
285
Evaluation ofProsthetic Aortic
Valves Using Echocardiography
Using Illustrative Case Examples
The TTE evaluation of a patient with an AV prosthesis requires a comprehensive 2D and Doppler
assessment of cardiac structure and function. The
specic spectral Doppler parameters essential to
assess aortic prostheses are listed in Table 22.1.
Case examples will be used to illustrate how to
utilize echocardiographic tools to assess prosthetic valve function.
Evaluation ofProsthetic Aortic Valves
Case 1
Patient with normal functioning bioprosthetic
valve in the aortic position.
2D Evaluation
2D TTE includes a comprehensive assessment of
ventricular chambers in addition to valve position
and leaet mobility. Videos 22.2 and 22.3 show
that the aortic bioprosthesis appears well seated
and has normal systolic leaet excursion.
Doppler Evaluation
Color Doppler is useful to detect areas of turbulence and regurgitation. Note the laminar ow
across the aortic prosthesis without turbulence or
regurgitation shown in Fig.22.8 with correspond-
ing Video 22.4.
The rst step in the hemodynamic assessment
of the aortic prosthesis is measuring the diameter
of the left ventricular outow tract (LVOT). This
is then followed by using CW and PW Doppler to
measure peak velocity and gradients followed by
calculation of the effective orice area (EOA)
and dimensionless index (DI).
The hemodynamic assessment of aortic prosthetic valve function using spectral Doppler is
illustrated in Fig.22.9.
Prosthetic Aortic Valve Dysfunction: Stenosis
Pathologic stenosis of prosthetic valves can occur
due to obstructive thrombus, pannus ingrowth,
malfunction of mechanical occluders, or because
of degenerative processes of bioprosthetic valves
over time (Figs.22.10 and 22.11). Careful spec-
286
G. A. Ayuba and V. Rigolin
Table 22.1
Parameter Normal Possible stenosis
Peak velocity (m/s) <3 3–4 >4
Mean gradient (mmHg) <20 20–35 >35
Acceleration Time (ms) <80 80–100 >100
Contour of jet velocity through the PrAV Early peaking,
Dimensionless index (DI)
Effective orice area (EOA) >1.2 0.8–1.2 <0.8
Fig. 22.8 End-systolic
frame of a Color
Doppler image of the
aortic prosthesis
showing normal laminar
ow
Spectral Doppler parameters required for the evaluation of aortic prosthetic function
Suggests signicant
stenosis
triangular
≥0.30
Triangular to
intermediate
0.25–0.29 <0.25
Rounded
tral Doppler evaluation can help determine the
presence of stenosis (Fig.22.12).
Case 2
85 y.o. female with aortic AV replacement
17years prior who presented with a complaint of
progressive exertional dyspnea.
2D imaging using TTE demonstrates an aortic
bioprosthesis with thickened leaets and reduced
leaet excursion (Videos 22.5 and 22.6). Spectral
Doppler assessment demonstrates severe bioprosthetic AV stenosis (Fig.22.13).
Elevated velocities and gradients across prosthetic aortic valves may not always represent pathologic obstruction. Patients may have high
transvalvular gradients with a normally functioning
prosthesis. This can occur in a high-ow state or
when the effective orice area is insufcient in meeting the cardiac output demand and is referred to as
patient–prosthesis mismatch and may be associated
with reduced short- and long-term survival [2, 5, 6].
Prosthetic Aortic Valve Dysfunction: Regurgitation
Case 3
72 y.o. male with a history of severe symptomatic
aortic stenosis deemed high risk for surgical AV
replacement who underwent a transcatheter aortic valve replacement (TAVR) 2months prior. He
presented with decompensated heart failure and
had a TTE and TEE performed for evaluation of
his AV prosthesis and paravalvular regurgitation.
22 Prosthetic Valves
287
a
The presence and severity of pathologic
paravalvular or transvalvular prosthetic regurgitation can be challenging to evaluate due to
the difculty visualizing color jets due to
acoustic shadowing, the often serpiginous
nature, and the eccentricity of paravalvular
regurgitation.
Evaluation by echo should include the
assessment of prosthesis position and stent/
leaet morphology in multiple views to identify
the etiology or mechanism of regurgitation.
b
Imaging should also include an adequate sweep
of the prosthesis to identify the origin and location of the regurgitant jet using color Doppler.
Grading the severity should include the use of
color and spectral Doppler and 3D imaging
assessment as recommended in published
guidelines [7].
Specic parameters essential to grading the
severity of aortic regurgitation following TAVR
or percutaneous prosthetic valve repair are listed
in Table22.2.
c
Studies have shown a higher incidence of
paravalvular regurgitation in transcatheter aortic
valve replacement compared to surgical aortic
valve replacement, and this has been shown to
have an impact on clinical outcomes with an
increased risk of recurrent hospitalization, cardiac death, and all-cause mortality with worsening severity [8, 9].
Fig. 22.9 Step by step analysis of aortic prosthetic valve
function. Panel A: LVOT diameter is measured from junction of the interventricular septum and sewing ring to
junction between anterior mitral leaet and posterior sewing ring. Panel B: CW Doppler of the AV prosthesis. Panel
C: PW Doppler of the LVOT
Measured variables suggest normal prosthetic valve
function:
Peak velocity=1.9m/s; Mean gradient=8.3mmHg
Calculated EOA = LVOT Area × LVOT VTI ÷ AV
VTI=2.2cm
Dimensionless index=LVOT VTI ÷ AV VTI=21.7cm ÷
37.8cm=0.57
2
TEE color Doppler images show paravalvular
regurgitation with a posterior origin surrounding
a balloon-expandable percutaneous valve (Videos
22.7 and 22.8).
Evaluation ofProsthetic Mitral Valves
The TTE evaluation of a patient with an MV
prosthesis requires a comprehensive 2D and
Doppler assessment of cardiac structure and
function. The specic spectral Doppler parameters essential to assess mitral prostheses are listed
in Table22.3.
Case 4
Patient with a history of symptomatic acute
severe mitral regurgitation due to a spontaneous
papillary muscle rupture who underwent an
emergent MV replacement with a bioprosthetic
valve.
TEE obtained intraoperatively following MV
replacement shows a well-seated bioprosthetic
288
Fig. 22.10 Surgical
specimen of excised
degenerative calcic
bioprosthetic aortic
valve (Courtesy of
S.Christopher
Malaisrie, MD)
G. A. Ayuba and V. Rigolin
Fig. 22.11 Surgical
specimen of excised
bioprosthetic aortic
valve with pannus
ingrowth (arrow)
resulting in pathologic
obstruction (Courtesy of
S.Christopher
Malaisrie, MD)
22 Prosthetic Valves
289
Fig. 22.12 Algorithm
for evaluation of aortic
Peak Prosthetic Aortic Jet Velocity > 3 m/s
valve prosthesis.
Adapted with
permission from Zoghbi
etal. [2]
DVI
≥ 0.30
0.25 – 0.29
Jet Contour
AT (ms) >100
Consider PrAV stenosis with
Sub-valve narrowing
Understimated gradient
Improper LVOT velocity*
Normal PrAV
EOA
Index
High FlowPPM
ab c
DVI
>100<100 <100
Suggests PrAV
Stenosis
DVI
< 0.25
Consider Improper
LVOT velocity**
Fig. 22.13 Evaluation of parameters for prosthetic AV
function assessment consistent with severe prosthetic
stenosis. Panel A: Measurement of the LVOT diameter.
Panel B: PW Doppler of the LVOT. Panel C: CW
Doppler of the aortic valve prosthesis
Measured variable suggest severe bioprosthetic aortic
Calculated EOA = LVOT Area X LVOT VTI ÷ AV
VTI=0.7cm
2
Dimensionless index= LVOT VTI ÷ AV VTI 16.2cm ÷
123.7cm=0.13
Mean gradient=55mmHg; Peak velocity=4.72m/s
Acceleration Time: 108ms
stenosis
Table 22.2
Doppler Parameters required for evaluation of aortic regurgitation after TAVR
Mild AR Moderate AR Severe AR
Vena contracta width (cm) <0.3 0.31–0.59 >0.6
2
Vena contracta area (cm
Circumferential extent (%) <10 11–29
Flow convergence Small or
) <0.10 0.11–0.29
Intermediate Large
≥0.30
≥30%
absent
PHT (ms) >500 200–500 <200
Diastolic ow reversal in descending
aorta
Regurgitant volume (ml) <30 30–59
Regurgitant fraction (%) <30 30–49
EROA (cm
2
) <0.1 0.1–0.29
Absent or brief Brief Prominent holodiastolic ow
reversal
≥60
≥50
≥0.3
Adapted from Zoghbi etal. [7]
290
G. A. Ayuba and V. Rigolin
Table 22.3
PHT (ms) <130 130–200 >200
Peak velocity (m/s) <1.9 1.9–2.5 >2.5
Mean gradient (mmHg)
DI: VTI
EOA (cm
Adapted from Zoghbi etal. [2]
Fig. 22.14 CW
Doppler assessment of a
bioprosthetic mitral
valve showing normal
prosthetic gradient
Spectral Doppler parameters required for evaluation of mitral prosthetic function
Normal Possible stenosis Signicant stenosis
6–10 >10
1–2 <1
prMV
2
)
/VTI
≤5
lvot
<2.2 2.2–2.5 >2.5
≥2.0
MV with normal diastolic leaet excursion and
laminar ow across the prosthesis (Videos 22.9
and 22.10) and normal prosthetic hemodynamic
assessment by spectral Doppler evaluation
(Fig.22.14) consistent with a normal functioning
MV prosthesis.
Prosthetic Mitral Valve Dysfunction: Stenosis
Case 5
Patient who presented with acute decompensated
heart failure. Echo demonstrated severe bioprosthetic mitral stenosis (Figs.22.15 and 22.16 with
corresponding Videos 22.11 and 22.12). The
patient underwent a subsequent transcatheter
valve-in-valve procedure given the elevated risk
for a redo MV surgery (Fig.22.17).
Gated CT can complement echo imaging for
the evaluation of leaets/occluder motion and
visualization of potential causes of prosthetic
valve dysfunction such as thrombus, vegetation,
or pannus formation [2].
Prosthetic Mitral Valve Dysfunction: Regurgitation
Case 6
56 y.o. male with history of mechanical mitral
valve replacement presenting with fever of
101.2°F and chills × 3days with positive blood
cultures for staph aureus.
22 Prosthetic Valves
291
a
b
Fig. 22.15 Examples of stenotic mitral prostheses: Panel
A: TEE showing a calcied stenotic bioprosthetic mitral
valve with restricted leaet opening at end diastole
(arrow). Panel B: 3D image of a mitral valve prosthesis
with restricted leaet motion at end diastole
Given clinical concern for endocarditis, he
underwent a TEE, which showed dehiscence of
his bi-leaet mechanical mitral valve with signicant perivalvular regurgitation along the lateral aspect of the prosthetic valve (Fig. 22.18,
Videos 22.13, 22.14, 22.15 and 22.16).
Evaluation ofProsthetic Pulmonic
andTricuspid Valves
Although data on right-sided prosthetic valves
are limited, the same principles and concepts of
prosthetic evaluation and native valve dysfunction govern their assessment.
Prosthetic Valve Endocarditis
Prosthetic valve endocarditis occurs due to
microbial infection of a prosthesis and may
present as vegetation characterized by an oscillating mass on the valve or supporting structures, dehiscence of the valve with new valvular
regurgitation, or abscess formation. The estimated in-hospital mortality rate remains at
15–20%; thus, accurate and timely diagnosis
to enable prompt and effective management is
vital [10].
The modied Duke criteria is the current standard for the diagnosis of infective endocarditis
and includes pathologic, imaging, and clinical
ndings [10–12].
Case 7
Patient with endocarditis of a bioprosthetic AV
(Fig.22.19 with corresponding Videos 22.17 and
22.18).
Prosthetic valve endocarditis has a lower incidence of vegetations compared to native valves
and has a higher incidence of annular abscess and
paravalvular complications, so the threshold for
early TEE assessment in these patients should be
low [11, 13].
Annular abscess is a life-threatening complication that requires surgical management and is
associated with conduction disease resulting in
heart block and a mortality rate of ≥40% [11, 13]
(Fig. 22.20 with corresponding Videos 22.19,
22.20, 22.21 and 22.22).
Other indications for early surgery for patients
with infective endocarditis include heart failure,
persistent bacteremia, infection with highly resistant organisms, or recurrent emboli with persistent vegetations [1, 11, 13].
Recognizing normal structure and function of
prosthetic valves is important to help identify the
presence of dysfunction or pathology. The aortic
root may be thickened in the early months
(3–6months) following aortic valve replacement
due to postop hematoma and edema, which may
be mistaken for an aortic root abscess. As such,
corroboration with an early post-operative study
is benecial [2] (Fig.22.21).
PET/CT is useful for evaluating patients with
equivocal TEE ndings and assessing complications such as annular abscess, as it is less affected
by shadow artifacts that may be seen on ultrasound [2, 11].
292
G. A. Ayuba and V. Rigolin
a
b
Fig. 22.16 Diastolic ow acceleration across the MV
prosthesis (Panel A). Spectral Doppler of the mitral prosthesis showing a peak velocity of 2.6m/s, a mean gradient
of 17mmHg at HR 65bpm, VTI=113ms and pressure
half time of 301ms (Panel B). Not shown are the LVOT
VTI=25cm and LVOT diameter=2.3cm that are used to
Prosthetic Valve Thrombosis
Mechanical Valve Thrombosis
The annual rate of prosthetic valve thrombosis with mechanical valves ranges from 0.1%
to 5.7% [1]. Mechanical valve thrombosis can
occur acutely or subacutely, resulting in valve
calculate the SV of LVOT=104 ml. The Dimensionless
index: MV VTI/LVOT VTI (113 ÷ 25 = 4.5). In the
absence of signicant mitral and aortic regurgitation, the
SV of LVOT can be used to calculate the MV
EOA. EOA = SV/VTIpv = 104/113 = 0.9 cm
parameters point to severe stenosis
2
. All
dysfunction, and is typically associated with
subtherapeutic anticoagulation with a vitamin
K antagonist (VKA). Patients may present with
shortness of breath due to acute valve dysfunction or embolic phenomena.
Mechanical valves require the use of lifelong
anticoagulation with a VKA at an appropriate
ab
22 Prosthetic Valves
Fig. 22.17 3D image of
new bioprosthetic valve
within old prosthesis
(valve-in-valve) with
noted non-restricted
pliable leaets at end
diastole
Fig. 22.18 TEE image
with the arrow showing
lateral periprosthetic
mitral regurgitation at
the site of dehiscence
293
Fig. 22.19 Vegetation on a bioprosthetic AV (arrow, panel A) resulting in valve destruction and valvular regurgitation
on color Doppler interrogation (arrow, panel B)
294
ab
Fig. 22.20 TEE image showing prosthetic valve endocarditis in the aortic position complicated by annular abscess
(arrow, panel A) and valve dehiscence resulting in posterior perivalvular regurgitation on color Doppler (panel B)
Fig. 22.21 Post op AV
replacement with
annular thickening due
to edema (arrow)
G. A. Ayuba and V. Rigolin
INR goal based on valve type and position. The
need for life-long anticoagulation with mechanical valves is a major consideration when electing
a strategy for valve disease management [14, 15].
An INR target of 2.5 (range, 2.0–3.0) is indicated for most patients with mechanical valve
prostheses in the aortic position; however, a
higher target of 3.0 (range, 2.5–3.5) is recom-
mechanical valves [14, 15]. There is a newer gen-
eration mechanical aortic valve prosthesis that
requires a lower INR target of 1.5-2.0.
By echo, mechanical prosthetic valve thrombosis is diagnosed by an abnormally elevated
velocity or gradient across the prosthesis, with
either limited leaet motion or attached mobile
densities consistent with thrombus.
mended if patients have risk factors associated
with a higher risk of thromboembolism, such
as left ventricular dysfunction, atrial brillation, prior thromboembolism, and ball-in-cage
Case 8
22 y.o. female with a history of MV replacement
with a bileaet mechanical prosthetic valve pre-