A 50-year-old man with no comorbidities requires aortic valve replacement. Either a mechanical or bioprosthetic valve could be used. A mechanical valve would require lifelong anticoagulation therapy. It would have a low risk of structural deterioration but higher risks of bleeding, thromboembolism, and reoperation. A bioprosthetic valve would avoid anticoagulation but have a higher risk of structural deterioration requiring reoperation. Long-term outcomes must be considered based on the patient's age, lifestyle, and risk tolerance for anticoagulation versus structural failure.

1. Valve selection
Weerachai Nawarawong M.D.

4. Children
Patients <40 yrs
High reoperation risk
Small annular size
Atrial fibrillation
Pregnancy desired
Patients > 70 yrs
High thromboembolism risk
High hemorrhage risk
Mechanical valve advantage
Tissue valve advantage
Akins CW: Ann Thorac Surg 1991,52:161-172

5. Which valve ?

6. • If one can choose the valve prosthesis
one would choose:
–“One valve for life”

7. 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

8. “Nine Commandments
for
prosthetic valve”
• Embolism Prevention
• Durability
• Ease and Security of Attachment
• Preservation of Surrounding Tissue Function
• Reduction of Turbulance
• Reduction of Blood Trauma
• Reduction of Noise
• Use of Materials Compatible with Blood
• Development of Methods of Storage and
Sterilization

9. Ideal valve
• Good hemodynamic
• Quiet
• Require no anticoagulation
• Last for life time
• Cheap
• Easy to implant

10. 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

11. 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) 5 10 15 20
survival rate (%) 85 66 53 38
re-operation (%) 22 62 85 95
* Circulation 1991; 84(suppl 3):III81-III88

12. Bleeding
and
thromboembolism
Durability
and
hemodynamic

13. Thromboembolism
and
Bleeding

14. Wall Street Journal 8//16//07
• Warfarin “is the second-most-likely drug,
after insulin, to send Americans to the em
ergency room”.
• By one estimate, it accounts for 43,000
ER visits a year in the U.S.

15. • Van der Meer :
– 42% more major bleeding complications for
every one-point increase in INR.
• The incidence from major bleeding
complications given in the literature varies
between 1.6% and 5.2 % increasing with a
ge

16. 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.)

17. Incidence Rates of Valve Thrombosis and Major and Total Embolisms: Effect
of Antithrombotic Treatment
Incidence Rates per 100 Patient-Years (95% Confidence Intervals)
Anticoagulation Valve Thrombosis Major Embolism Total Embollsm*
None 1.8 (0.9-3.0) 4.0 (2.9-5.2) 8.6 (7.0-10.4)
Antiplatelet 1.6 (1.0-2.5) 2.2 (1.4-3.1) 8.2 (6.6-10.0)
Dipyridamole 4.1 (1.9-7.2) 5.4 (2.8-8.8) 11.2 (7.3-15.9)
Aspirin 1.0 (0.4-1.7) 1.4 (0.8-2.3) 7.5 (5.9-9.4)
Coumadin 0.2 (0.2-0.2) 1.0 (1.0-1.1) 1.8 (1.7-1.9)
Coumadin and antiplatelet 0.1 (0.0-0.3) 1.7 (1.1-2.3) 3.2 (2.4-4.1)
(Circulation. 1994;89:635-641.)

18. 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.)

19. Types of prosthetic valves and thrombogenicity
Type of valve Model Thrombogenicity
Mechanical
Caged ball Starr­Edwards + + + +
Single tilting disc Bjork­Shiley,
Medtronic Hall + + +
Bileaflet St Jude Medical,
Sorin Bicarbon,
Carbomedics + +
Bioprosthetic
Heterografts Carpentier­Edwards,
Tissue Med (Aspire), Hancock II + to + +
Homografts +

22. • Mitral heart valve prostheses carry
a risk of embolism that is almost
twice as high as aortic valve prosth
eses
• Cannegieter SC, Rosendaal FR, Briet E (1994) Thromboembolic and bleeding
complications in patients with mechanical heart valve prostheses. Circulation 89 :635
–641

23. 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

24. Hemodynamic advantages

27. Comparison of mean pressure gradients for
commonly implanted prosthetic valves.
Gradient

28. Comparison of EOAs for commonly implanted
prosthetic valves.
EOA

29. Patient prosthesis mismatch

32. • 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 y
ounger 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 r
equiring aortic valve replacement? J Thorac Cardiovasc Surg. 2005;129:1041–1049.

34. Reasons for increasing use of
Bioprosthesis
• Newer generation bioprosthesis are more durable and better.
• Reoperation rates for patients over 65 years of age are particularly
low with modern stented bioprostheses
• The risks of reoperation have continued to decrease
• Patients undergoing AVR today are older population than those
studied in the randomized trials.
• Young patients undergoing aortic valve surgery are often reluctant
to accept warfarin therapy and the activity constraints associated wit
h anticoagulants.
• There are some nonrandomized but relatively large comparative
trials that have shown apparent survival benefit for patients receivin
g bioprostheses, particularly for those over the age of 65 years .

35. Why bioprosthesis
• Better fixation technique
• Better anticalcification technique
• Better long term result in newer generation
valve
• Better surgical technique , redo less
dangerous

36. Durability

37. • Two historic randomized clinical trials compared
outcomes after valve replacement with a first-ge
neration porcine heterograft and the original Bjor
k-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.

38. • The Edinburgh trial
– a small survival advantage associated with a
mechanical valve in the aortic but not in the mitral pos
ition;
• 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.

46. • 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.

47. • 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 year
s 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.

48. • Advances in tissue fixation and
anticalcification treatment have resulted in
current-generation bioprostheses that hav
e superior durability

50. 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 prospe
ct 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.

53. 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.

54. Hancock Valve Durability Data

55. ACC/AHA VHD Guidelines: 2008

56. ACC/AHA VHD Guidelines: 2008

57. 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

58. O’Brien et al,2001
Aortic Homograft Durability vs Age: Freedom from Re-op

59. 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

60. The main indication for re-operation
of mitral valve prostheses
• Structural deterioration of (tissue) valves,
• Endocarditis,
• Para- valvular defects,
• Valve thrombosis,
• Pannus formation
• Residual or recurrent tricuspid incompetence.
• Progressive coronary artery disease

61. Risk factors for early mortality
after reoperation
• Emergency operation for thrombosis of a
prosthesis,
• Acute endocarditis,
• Acute valvular dehiscence with clinical
deterioration, and surgical problems.
• Older age and NYHA class also play a
major role

62. 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 %

63. 50-year-old man with no
comorbidities undergoing
aortic valve replacement

64. 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 re
operation.
• Valve-related mortality is
• 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%).
• Valve-related morbidity
– 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%),
• Cumulative 108.6% risk of valve-related morbidity or mortality (30.6%
mortality78% morbidity) over 30 years.
• 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.

65. 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
– 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%)
• 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).
• 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.

66. Projected Future Risks After Aortic Valve Replacement in a 50-Year-Old Man, Assuming
30-Year Survival
Mechanical Valve Bioprosthetic Valve
Replacement, % Replacement, %
Operative mortality 1.5
1.5
Death at reoperation (risk
of reoperationrisk of 2.1 5.8
death at reoperation) (10.8 for second
reoperation)
Valve-related mortality
(cumulative for 30 y) 27 29
Valve-related morbidity
(cumulative for 30 y) 78 12
Total risk of morbidity and 108.6 48.3
mortality over 30 y (59.1 if 2 reoperations)

67. Durable valve repair
possible
No
Yes
Life expectancy
<15 yr co morbidity
Life expectancy 15-30 yr
No co morbidity
Life expectancy >30 yr
No co morbidity
Accept risk of
reoperation
No coagulation
Minimal life style
change
No reoperation
Will take
anticoagulation
Accept life style
change
Tissue valve Mechanical valve
Physician
assessment
Patient
preference
Valve repair

68. • 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.
• “No one should test the depth of a river
with both feet.”
• Lawrence Bonchek, M.D