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Luis J. Castro, MD Vincent A. Gaudiani, MD
Audrey L. Fisher, MPH
Aortic Valve Replacement: Strategies to Improve Outcomes
(1998-2004)Sequoia Hospital
Redwood City, CA
Prosthesis-Patient Mismatch (PPM)
DefinitionDefinition: Valve Prosthesis too small relative : Valve Prosthesis too small relative
to patient’s body size to patient’s body size
ConsequenceConsequence: Persistence of abnormally : Persistence of abnormally
high postoperative gradients…the reason why high postoperative gradients…the reason why
we operate on patients with A.S. in the first we operate on patients with A.S. in the first
placeplace
Mismatch ???Mismatch ???
Gradient = Gradient = QQ22
K K EOA EOA22
Cardiac Output (mL/min)Cardiac Output (mL/min)
EOA (cmEOA (cm22))
Gradient (mmHg)Gradient (mmHg)
MouseMouse
5050
0.30.3
11
ElephantElephant
50 00050 000
5050
11
ElephantElephantMismatchMismatch
50 00050 000
0.30.3
11 000 00011 000 000
We are not created equal !
Are Big Valves Better?
Physics of flow through a tube:
Resistance 1/radius 4
small increase in size causes a significant reduction in LV work.
Definition of PPM Based on Indexed EOA of Prosthesis
Hanayama et al, Ann Thorac Surg 2002;73:1822–9Pibarot & Dumesnil JACC 2000; 36: 1131-41Pibarot & Dumesnil JACC 2000; 36: 1131-41
1.0 1.5 2.0 2.5 3.0 3.5
0
10
20
30
40
50
Postoperative Mean Gradient at Rest (mmHg)Postoperative Mean Gradient at Rest (mmHg)
Indexed internal Indexed internal geometric area (cmgeometric area (cm22/m/m22))
Indexed IGA vs. Projected Indexed EOA as Predictors of Gradients
StentedStentedStentlessStentless
r=0.35r=0.35
0.50 0.85 1.20 1.55
0
10
20
30
40
50
MismatchMismatch r=0.67r=0.67
Projected indexed Projected indexed EOA (cmEOA (cm22/m/m22))
Pibarot et al. Ann Thorac Surg 2001; 71: S265-8.Pibarot et al. Ann Thorac Surg 2001; 71: S265-8.
Impact of PPM on Clinical Outcomes
Less improvement in functional class Increased incidence of late cardiac
events Minimal regression of LVH Moderate impact on late mortality
(>7years) Major impact on perioperative mortality,
particularly if LV dysfunction presentPibarot & Dumesnil, JACC 2000; 36: 1131-1141Pibarot & Dumesnil, JACC 2000; 36: 1131-1141Blais et al, Circulation 2003;108: 983-988
PPM is Predictive of Congestive Heart Failure after AVR
1681 patients, mean follow-up 4.4 years1681 patients, mean follow-up 4.4 yearsIndependent predictors of CHF (NYHA 3-4 or CHF death):Independent predictors of CHF (NYHA 3-4 or CHF death): AgeAge Preop. NYHA classPreop. NYHA class Elevated diastolic pulmonary arterial pressuresElevated diastolic pulmonary arterial pressures Atrial fibrillationAtrial fibrillation Coronary artery diseaseCoronary artery disease SmokingSmoking Redo statusRedo status PPM (EOAI PPM (EOAI 0.80 cm0.80 cm22/m/m22): 60% increase in the risk of CHF): 60% increase in the risk of CHF
Ruel et al, JTCVS 2003; 127:149-159
Impact of PPM on LV Mass Regression
109 patients with a CEP bioprosthesis109 patients with a CEP bioprosthesis53% had PPM based on an indexed EOA 53% had PPM based on an indexed EOA 0.9 cm 0.9 cm22/m/m22
Tasca et al., Ann Thorac Surg, 79:505-510, 2005
-100
-80
-60
-40
-20
0
-77-7749 g49 g P=0.002P=0.002
-48-4847 g47 g
No PPM PPM
Independent predictors Independent predictors of greater LV mass regression:of greater LV mass regression:- Female GenderFemale Gender- Higher Preoperative LV massHigher Preoperative LV mass- Larger Indexed EOALarger Indexed EOA
Impact of PPM on Short-Term Impact of PPM on Short-Term Mortality after AVR (1266 pts)Mortality after AVR (1266 pts)
05
101520253035
NonSignificant
Moderate Severe
Short-term Short-term mortality mortality
(%)(%)
3%3% 6%6%
26%26%
P = 0.015P = 0.015
P < 0.001P < 0.001P P << 0.001 0.001
(Overall = 4.6%)
792 (62%)
Mismatch
# of pts 447 (36%) 27 (2%)EOAI (cmEOAI (cm22/m/m22)) > 0.85> 0.85 0.85 and > 0.650.85 and > 0.65 0.650.65
Blais et al, Circulation,108:983-988, 2003
Impact of Valve Prosthesis-Patient Mismatch on Short-Term Mortality After Aortic Valve Replacement
Claudia Blais, BSc; Jean G. Dumesnil, MD; Richard Baillot, MD, et al.Circulation. 2003;108:983.
7%p=0.05
16%p<0.001
67%p<0.001
3%5%
p=0.08
23%p<0.001
0%10%20%30%40%50%60%70%
Mor
talit
y
Non significant Moderate Severe
Valve prosthesis-patient mismatchiEOA < 0.65iEOA = 0.65 - 0.84iEOA > 0.85
LVEF 40%
LVEF < 40%
A l l A o r t ic V a lv e P r o c e d u r e s1 9 9 8 - 2 0 0 4 ( n = 1 3 1 2 )
S t a n d a r d A V R7 2 % ( 9 4 1 )
A R E1 7 % ( 2 2 6 )
A o r t ic R o o t R e c o n s t r u c t io n
1 1 % ( 1 4 5 )
How to Avoid Mismatch
Achieve proper sizing in all patients: Ask for the patient’s BSA to anticipate a minimum valve
size that gives the patient at least 0.85 cm2/m2 of valve area
At the time of operation, if the appropriate valve sizer fits or the annulus is larger– use the minimum valve size or larger
If the sizer is too big – decide on aortic root enlargement (ARE) or aortic root reconstruction (AoRR)
Valve Sizing (stented valves)
BSA approx 1.5 (50 kg) size 21 or larger
BSA approx 1.75 (75 kg) size 23 or larger
BSA approx 2.0 (>90 kg) at least size 25
Valve Sizing (Poor EF’s)
BSA approx 1.5 (50 kg) at least size 23
BSA approx 1.75 (75 kg) at least size 25
BSA approx 2.0 (>90 kg) at least size 27
How do you choose AVR or ARE?
Use ARE if: ARE for 1-2 sizes larger… You can sew Dacron graft to the
aortotomy Speed matters There is a lot of calcium around
the coronary ostia
How do you choose ARE or AoRR?
Use AoRR if: You need the largest orifice
possible The coronary ostia are not calcified The root is a terrible mess
Choice of Valve Conduit
We use a homograft for acute endocarditis
We use the Freestyle valve as a root for most other applications
Ross operation for Children
Risk of Anticoagulation Related Hemorrhage
The composite linearized rate of anticoagulation related hemorrhage in several large series averages 0.9 – 2.5% per year.
Akins, Ann Thor Surg61:806, 1996
Operative Results
First Op(n=887)
Reop(n=326) p-value
Operative Death (30 day) 4.1% 3.1% NS
Cerebrovascular Accident 4.7% 4.0% NSVent > 24h 11.9% 16.3% NSReexploration for bleed 4.6% 5.2% NSComplete Heart Block 7.7% 9.8% NSRenal Failure 3.4% 6.7% .027Postop LOS 8.4 9.7 <.001
Choice of Valve
In our hands, the risk of reoperation and the risks of coumadin are about equal, so we encourage the patient to decide on tissue v. mechanical valve replacement.
Prostheses Types Used: AVR or ARE
Tissue95%
Mechanical5%
Prostheses Types Used: AoRR
Tissue77%
Mechanical5% Homograft
18%
Aortic Valve Prostheses Types by Year
0255075
100125150175200225250
1998(n=138)
1999(n=171)
2000(n=161)
2001(n=196)
2002(n=211)
2003(n=186)
2004(n=249)
HomograftMechanicalStentlessStented Bio
Introduction of Introduction of MosaicMosaic
Root enlargement (ARE)
70 y.o. woman, critical A.S., severe dyspnea, chronic Afib, Cr=4.0.
Wt 91kg., BSA = 1.89, annular diameter by TEE is 20.5mm.
Probable ARE vs. AoRR to achieve iEOA = 0.85.
O.R. Case
How Have We Faired?
A l l A o r t ic V a lv e P r o c e d u r e s1 9 9 8 - 2 0 0 4 ( n = 1 3 1 2 )
S t a n d a r d A V R7 2 % ( 9 4 1 )
A R E1 7 % ( 2 2 6 )
A o r t ic R o o t R e c o n s t r u c t io n
1 1 % ( 1 4 5 )
Preoperative Characteristics:All AVR, ARE, & AoRR
0102030405060708090
100
Mean Age% NYHA 3+ % Female % PrevSurg
% EF < 30
AVR
ARE
AoRR
Proportion of Isolated Cases
45%
55%50% 50%
41%
59%
0%
10%
20%
30%
40%
50%
60%
AVR ARE AoRR
IsolatedNon-isolated
Concomitant Procedures:All AVR, ARE, & AoRR
0%5%
10%15%20%25%30%35%40%45%50%
CAB MVV/R Oth Procs
AVR ARE AoRR
Intraoperative Time:Isolated AVR, ARE, & AoRR
59
74
89
46
60
75
0102030405060708090
Tim
e (m
inut
es)
CPB X-Clamp
Iso AVR(n=297)Iso ARE(n=62)Iso AoRR(n=35)
Iso AVR X-Clamp Time National Average = 73.0 min (STS 2004)
% of Patient-Prosthesis MismatchStandard AVR vs. ARE
Standard Standard AVRAVR
AREARE
iEOA < 0.85 cm2/m2
1.6%
iEOA < 0.85 cm2/m2
1.4% No Statistical Difference in Mismatch
Mosaic Valve Size Distribution:Sequoia vs. National
05
10152025303540
Prop
ortio
n of
Pat
ient
s
19 21 23 25 27 29Labeled Valve Size (mm)
SeqMosaic(02)Nat'lMosaic
N = 820
Postoperative Outcomes:All AVR, ARE, & AoRR
2.6%
0.0%
3.8%
6.2%
4.4%
5.3%
0%
1%
2%
3%
4%
5%
6%
7%
8%
CVA Reop Bleed
AVRAREAoRR
Operative Mortality by Aortic Procedure (All Inclusive)
3.4%
5.5%
9.0%
0.0%
2.0%
4.0%
6.0%
8.0%
10.0%
12.0%
AVR ARE AoRR
NS
(p=.003)
NS – not significant at p = 0.05
Operative Mortality by Isolated Aortic Procedure
3.1%
4.4%
2.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
Iso AVR(n=384)
Iso ARE(n=90)
Iso AoRR(n=50)
No significant differences between groups at p = 0.05
Operative Mortality by Age All Aortic Procedures
0%
1%
2%
3%
4%
5%
6%
7%
% M
orta
lity
0-49(n=98)
50-64(n=238)
65-79(n=586)
80+(n=265)
Age Group
Impact of LV dysfunction?
Preoperative Characteristics:All AVR by EF
0102030405060708090
100
Mean Age % NYHA 3+ % Female % Prev Surg % Prev MI
EF>40mean=56.2%
EF<40mean=32.9%
*All significant at p=0.01
Concomitant Procedures by EF
0%5%
10%15%20%25%30%35%40%45%50%
CAB MVV/R Tricuspid
EF>= 40EF<40
*Significant at p=0.01
*
*
EF>40EF<40
% of Patient-Prosthesis MismatchBy Left Ventricular Function
EFEF>>4040 EF<40EF<40
iEOA < 0.85 cm2/m2
0.6%
iEOA < 0.85 cm2/m2
2.1%
0%
5%
10%
15%
20%
25%
30%
35%
40%
% P
atie
nts
19 21 23 25 27 29 31+Valve Size (mm)
EF>=40
Valve Size HistogramBy Left Ventricular Function
EF>40EF<40
Average iEOA:EF>40 = 1.22EF<40 = 1.27*Significant at p=0.01
Sequoia Hospital: 1998-2004Operative Mortality by EF for All AVR
4.3%5.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
EF > 40 (n=901) EF < 40 (n=380)
Not statistically different at p = 0.01
Conclusions
Value of AVR for Aortic Stenosis is relief of left ventricular outflow obstruction.
Mismatch can be avoided without increasing operative mortality by choosing the correct operation
Strategy to maximize iEOA in patients with impaired ventricular function can improve operative outcomes in this “high-risk” group