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