Heart Valve
selection
Weerachai Nawarawong M.D.
Inter-hospital conference
March 19, 2011
Mechanical valve advantage
Children
Patients <40 yrs
High reoperation risk
Small annular size
Atrial fibrillation
Pregnancy desired
Patients > 70 yrs
High thromboembolism risk
High hemorrhage risk
Tissue valve advantage
Akins CW: Ann Thorac Surg 1991,52:161-172
Which valve ?
• If one can choose the valve prosthesis one
would choose:
–“One valve for life”
Myths about Mechanical Valves
•
•
•
•
You’ll Never Need Another Operation
You can Live without Restrictions
Risks of TE/ACH are Minimal
Coumadin is Not a Problem
Ideal valve
•
•
•
•
•
•
Good hemodynamic
Quiet
Require no anticoagulation
Last for life time
Cheap
Easy to implant
Valve Prosthesis
• Mechanical
– types: caged-ball, tilting-disk, bi-leaflet
– advantage: durability
– limitation: thrombogenicity
• Bioprosthetic
– types: heterografts, homografts
– advantage: short term anticoagulation
– limitation: structural failure
• leaflet calcification & tissue degeneration leading to
valvular regurgitation
– Rate of porcine valve degeneration
26% (aortic), 39% (mitral) in 10 yrs
Homografts
• 1956 - first aortic valve homograft was
used in the descending thoracic aorta for
aortic regurgitation
• 1962 - first sub-coronary use
• High incidence of post-op failure *
(years)
survival rate (%)
re-operation (%)
5
85
22
10
66
62
15
53
85
* Circulation 1991; 84(suppl 3):III81-III88
20
38
95
Durability
and
hemodynamic
Bleeding
and
thromboembolism
Thromboembolism
and
Bleeding
Wall Street Journal 8//16//07
• Warfarin “is the second-most-likely drug,
after insulin, to send Americans to the
emergency room”.
• By one estimate, it accounts for 43,000 ER
visits a year in the U.S.
Incidence of major embolism
after
mechanical valve replacement
• Absence of antithrombotic therapy
– 4% per year
– plus 1.8% per year risk of valve thrombosis
• Antiplatelet therapy
– 2.2% per year
– plus 1.6% per year risk of valve thrombosis
• Wafarin therapy
– 1% per year
• 0.8% per year with an aortic valve
• 1.3% per year with a mitral valve
– plus 0.2% per year risk of valve thrombosis
• Incidence of major bleeding in patients treated with
warfarin
– 1.4 per 100 patient-years.
(Circulation. 1994;89:635-641.)
Incidence Rates of Valve Thrombosis and Major and Total Embolisms
With Coumadin Therapy: Effect of Valve Position
Incidence Rates per 100 Patient-Years
(95% Confidence Intervals)
Valve Position
Valve
Thrombosis
Major
Embolism
Total
Embolism*
Aortic
0.1 (0.1-0.2)
0.8 (0.7-0.9)
1.1 (1.0-1.3)
Mitral
0.5 (0.3-0.7)
1.3 (1.1-1.5)
2.7 (2.3-3.0)
Both
0.4 (0.2-0.7)
1.4 (1.0-1.9)
2.1 (1.6-2.7)
(Circulation. 1994;89:635-641.)
Types of prosthetic valves and thrombogenicity
Type of valve
Model
Thrombogenicity
Mechanical
Caged ball
StarrEdwards
++++
Single tilting disc
BjorkShiley,
Medtronic Hall
+++
St Jude Medical,
Sorin Bicarbon,
Carbomedics
++
Bileaflet
Bioprosthetic
Heterografts
Homografts
CarpentierEdwards,
Tissue Med (Aspire),
Hancock II
+ to + +
+
Zellner et al “Long term experience With the St.Jude Medical
Valve Prosthesis”
South Carolina,USA
AVR
418 pts, mean age 54.8yrs Re-operation inc. 1.0%/pt/y
Hemodynamic advantages
Gradient
Comparison of mean pressure gradients for
commonly implanted prosthetic valves.
EOA
Comparison of EOAs for commonly implanted
prosthetic valves.
Circulation 2009;119;1034-1048
Circulation 2009;119;1034-1048
Late Overall Survival and Freedom From Cardiovascular Death
Non significant PPM
Moderate PPM
Severe PPM
J. Am. Coll. Cardiol. 2009;53;39-47
• There are trends in the United States and
Europe toward the increasing use of tissue
rather than mechanical valves and toward
the use of bioprostheses in progressively
younger patients
•
Dagenais F, Cartier P, Voisine P, Desaulniers D, Perron J, Maillot R, Raymond G, Métras J, Doyle
D, Mathieu P. Which biologic valve should we select for the 45- to 65-year-old age group
requiring aortic valve replacement? J Thorac Cardiovasc Surg. 2005;129:1041–1049.
Reasons for increasing use of
Bioprosthesis
• Newer generation bioprosthesis
–
–
–
–
more durable and better.
Better fixation technique
Better anticalcification technique
Better long term result in newer generation valve
• The risks of reoperation have continued to
decrease
• Patients undergoing AVR today are older
population
• Young patients are often reluctant to accept
warfarin therapy and the activity constraints
associated with anticoagulants.
• There are survival benefit for patients receiving
bioprostheses, in age > 65 years .
Durability
• Two historic randomized clinical trials compared
outcomes after valve replacement with a firstgeneration porcine heterograft and the original
Bjork-Shiley tilting-disc mechanical valve:
– The Edinburgh Heart Valve Trial, conducted
between 1975 and 1979 with an average follow-up of
12 years,
– The Veteran Affairs (VA) Cooperative Study on
Valvular Heart Disease, conducted between 1979
and 1982 with an average follow-up of 15 years.
• The Edinburgh trial
– a small survival advantage associated with a
mechanical valve in the aortic but not in the mitral
position;
• both trials showed
– increased bleeding associated with mechanical valves
– increased reoperation with tissue valves;
– structural failure of tissue valves and overall
thromboembolic complications were greater after
mitral than after aortic valve replacement.
• A meta-analysis of 32 articles evaluated
mortality from 15 mechanical and 23 biological
valve series including 17,439 patients and 101,
819 patient-years of follow-up.
– no difference in riskcorrected mortality between
mechanical and bioprosthetic aortic valves regardless
of patient age
– choice between a tissue and mechanical valve should
not be based on age alone.
•
Lund O, Bland M. Risk-corrected impact of mechanical versus bioprosthetic valves on long-term
mortality after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;132:20 –26.
• Retrospective study comparing mechanical and
tissue aortic valve replacement in 3062 patients
with combined follow-up of 22 182 patientyears
– age but not valve type was predictive of valve-related
mortality.
– reoperation was higher after tissue aortic valve
replacement only for patients ≤60 years of age,
– combined valverelated morbidity was higher after
mechanical valve replacement for all patients 40
years of age.
•
Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ.
Performance of bioprostheses and mechanical prostheses assessed by composite of valve-related complications to
15 years after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;131:1267–1273.
Hypothetical model for the structural deterioration of bioprosthetic valves
• Advances in tissue fixation and
anticalcification treatment have resulted in
current-generation bioprostheses that
have superior durability
Freedom from structural valve
deterioration
• Carpentier-Edwards pericardial aortic valve (age 65)
– 94% at 10 years
– 77% at 15 years
– 10% chance that a 65-year-old patient would require reoperation
before 80 years of age.
• Third-generation bioprostheses may be even more durable, with
– 92.8% at 12 years (mean age of 54 years)
• In addition, advances in myocardial protection and cardiac surgical
techniques have led to lower risks at reoperation, making the
prospect of redo valve surgery less dangerous.
•
•
Banbury MK, Cosgrove DM III, White JA, Blackstone EH, Frater RWM, Okies JE. Age and valve size effect on the
long-term durability of the Carpentier-Edwards aortic pericardial bioprosthesis. Ann Thorac Surg. 2001;72:753–
757.
Bach DS, Metras J, Doty JR, Yun KL, Dumesnil JG, Kon ND. Freedom from structural valve deterioration among
patients 60 years of age and younger undergoing Freestyle aortic valve replacement. J Heart Valve Dis. In press.
Freedom from structural valve
deterioration after 15 years
• 2nd generation Hancock II aortic
valve
– 81.5% ( age 65 years)
• 1st generation Hancock bioprosthesis.
– 57.4% (age 69 years )
•
•
David TE, Ivanov J, Armstrong S, Feindel CM, Cohen G. Late results of heart valve replacement
with the Hancock II bioprosthesis. J Thorac Cardiovasc Surg. 2001;121: 268–278.
Cohn LH, Collins JJ Jr, Rizzo RJ, Adams DH, Couper GS, Aranki SF. Twenty-year follow-up of the
Hancock modified orifice porcine aortic valve. Ann Thorac Surg. 1998; 66(suppl):S30 –S34.
Hancock Valve Durability Data
ACC/AHA VHD Guidelines: 2008
ACC/AHA VHD Guidelines: 2008
M.O’Brien et al “The Homograft Aortic Valve:29 yrs”
J. Heart V. Dis 2001;10:334-345
1,022 patients mean age 47yrs: Actuarial Survival
O’Brien et al,2001
Aortic Homograft Durability vs Age: Freedom from Re-op
Reasons for tissue valve
•
•
•
•
Expected life expectancy < 10-12 yrs
Anticoagulation contraindicated.
Patient cannot or will not take anticoagulant.
Patient at increased risk for bleeding with
anticoagulation.
• INR difficult to control
• Poor compliance
• Difficult follow up
Reoperation
• Single mitral valve re-replacement
– elective
– normal left and right ventricular function
– risk 1.5 % .
• The peri-operative mortality with
–
–
–
–
emergency operation up to 40%,
double valve replacement to 22%,
with poorer NYHA class, (from 2.2% to 15.5%),
concomitant procedures to 16 %
50-year-old man with no
comorbidities undergoing
aortic valve replacement
Mechanical aortic valve replacement
•
•
Anticipated, operative mortality is 1.5% EuroSCORE regardless of the
prosthesis implanted.
After mechanical valve replacement,
–
–
0.3%/y chance of reoperation,yielding a 9% risk of reoperation if the man lives
to be 80 years of age.
chance of death at reoperation is 24%,assuming that reoperation is done on an
emergency basis at 65 years of age, yielding a 2.1% chance of death at
reoperation.
•
Valve-related mortality is
•
Valve-related morbidity
•
Cumulative 108.6% risk of valve-related morbidity or mortality (30.6%
mortality78% morbidity) over 30 years.
•
•
•
•
•
–
–
–
–
0.5%/y for a patient 51 to 60 years of age
1.1%/y in patients 61 years of age,
yielding a cumulative risk of valverelated mortality of 27% over 30 years: (10 0.5%)(20
1.1%).
2.2%/y for a patient 51 to 60 years of age,
2.7%/y for a patient 61 to 70 years of age,
2.9%/y for a patient 71 years of age,
yielding a cumulative risk of valve-related morbidity of 78% over 30 years, (10
2.2%)(10 2.7%) (10 2.9%),
Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ. Performance of bioprostheses and mechanical
prostheses assessed by composite of valve-related complications to 15 years after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;131:
1267–1273.
Roques F, Michel P, Gladstone AR, Nashef SAM. The logistic EuroSCORE. Eur Heart J. 2003;24:1–2.
Bioprosthesis valve replacement
•
•
At least 1 anticipated reoperation before 80 years of age. If reoperation occurs at 65
years of age (15 years after initial surgery), operative risk is 5.8%,assuming that
surgery is done electively.
The anticipated risk of valve-related mortality after bioprosthetic valve replacement
is
–
–
–
–
0.6%/y for a patient 51 to 60 years of age,
1.0%/y for a patient 61 to 70 years of age,
1.3%/y for a patient 71 years of age,
yielding a cumulative risk of valve-related mortality of 29% over 30 years: (10 0.6%)(10
1.0%)(10 1.3%), similar to that after mechanical valve replacement.
•
Valve-related morbidity
•
Cumulative 48.3% risk of valve-related morbidity or mortality— 36.3% mortality12%
morbidity— over 30 years.
Even if the patient required a second reoperation, the cumulative risk increases by
only 10.8% (calculated at 75 years of age).
•
•
–
–
–
–
0.3%/y for a patient 51 to 60 years of age,
0.4%/y for a patient 61 to 70 years of age,
0.5%/y for a patient age 71 years of age,
yielding a cumulative risk of valve-related morbidity of 12% over 30 years—(10 0.3%)(10
0.4%) (10 0.5%)
Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet
GJ. Performance of bioprostheses and mechanical prostheses assessed by composite of valverelated complications to 15 years after aortic valve replacement. J Thorac Cardiovasc Surg.
2006;131: 1267–1273.
Projected Future Risks After Aortic Valve Replacement in a 50-Year-Old Man,
Assuming 30-Year Survival
Mechanical Valve
Replacement, %
Operative mortality
Death at reoperation (risk
of reoperationrisk of
death at reoperation)
reoperation)
1.5
2.1
Bioprosthetic Valve
Replacement, %
1.5
5.8
(10.8 for second
Valve-related mortality
(cumulative for 30 y)
27
29
Valve-related morbidity
(cumulative for 30 y)
78
12
Total risk of morbidity and
mortality over 30 y
108.6
48.3
(59.1 if 2 reoperations)
Durable valve repair
possible
Yes
No
Physician
assessment
Life expectancy
<15 yr co morbidity
Patient
preference
Life expectancy 15-30 yr
No co morbidity
Accept risk of
reoperation
No coagulation
Minimal life style
change
Tissue valve
Life expectancy >30 yr
No co morbidity
No reoperation
Will take
anticoagulation
Accept life style
change
Mechanical valve
Valve repair
• If the patient’s characteristics do not sway
the balance in favor of any particular valve
substitute,
• The surgeon should use the valve most
familiar to him.
• Lawrence Bonchek, M.D
What will be the future ?
Transcatheter Aortic Valve
Replacement
Transapical (2005)
Minimally Invasive Redo
Xenograft Replacement
+
=
(T. Walther. AHA 2006)
“In the future ,Valve selection
will continue to change pending
on new technological
development”