METAΛΛΙΚΗ ΠΡΟΣΘΕΤΙΚΗ ΒΑΛΒΙΔΑ-ΑΥΤΟΝΟΜΗ ΝΟΣΟΣ?
Γ.ΔΡΟΣΟΣ
Καρδιοχειρουργική Κλινική
ΓΝΘ Γ. Παπανικολάου, Θεσσαλονίκη
Valve replacement since early 1960s improved outcome
of pts with valvular heart disease
90 000 valve substitutes each year in US
280 000 worldwide each year
Half mechanical, half bioprosthetic valves
Despite improvements in prosthetic valve design and
surgical procedures , valve replacement does not provide
a definitive cure
Disease is a medical condition associated with specific
symptoms and signs, caused by internal dysfunction or
external factors that produce clinical impairment of normal
function
Native valve disease is traded for “prosthetic valve
disease” ?
Replacement of a diseased heart valve with a prosthetic
valve exchanges the native disease for complications that
are peculiar to the prosthesis.
• epidemiological and clinical features
PROSTHETIC VALVE DISEASE
(long term complications)
Valve thrombosis
Systemic emboli
Bleeding – anticoagulation related
Structural Valve Degeneration
Infection
Hemolysis
Thrombosis of prosthetic heart valves: diagnosis and
therapeutic considerations
Acute or subacute presentation
Thrombus formation, pannus ingrowth, or combination
Pannus ingrowth (subvalvular annulus) in both bioprosthesis and
mechanical
Thrombus in mechanical valves due to inadequate antithrombotic
therapy or in bioprosthetic valves in the early postop period
0.3-1.3% per pt-yr obstructive valve thrombosis in mechanical
Raudart et al. Heart 2007;93:137–142
Late incidence and determinants of stroke after aortic and
mitral valve replacement
20% of pts have an embolic stroke by 15 years after valve
replacement
Intracranial bleeding event 0.2-0.3% per pt yr
RISK FACTORS
age>75 yrs, female, smoking, CAD, AF with aortic prostheses
mechanical type, advanced LV dysfunction with mitral prostheses
* No effect of 3 months anticoagulation in bioprostheses
No effect of aspirin adjunct
Ruel et al. Ann Thorac Surg 2004;78:77– 84
Anticoagulant-Related Hemorrhage
annual risk of a hemorrhagic event is 1% per pt-yr
more common with a mechanical due to excessive anticoagulation
Structural Valve Degeneration
Degenerative and atherosclerotic process- immune?
Extremely rare with mechanical valves
RISK FACTORS: younger age, mitral position, renal insufficiency, and
hyperparathyroidism
Hypertension, LV hypertrophy, poor LV function, and prosthesis size
for the aortic position
Most frequent cause of reoperation in bioprostheses
rate of failure of 10% at 10 years in pts>70yrs and 20-30% in pts <40 yrs
Infective Endocarditis
0.1-2.3 % per pt-yr, even with appropriate antibiotic prophylaxis
high mortality rates (30% to 50%)
Risk for early PVE is higher (5%) when for active endocarditis
Risk for late PVE is lower for mechanical than for bioprostheses
BIO: 0.49% per pt year for MV and 0.91% for AV
MECH: 0.18% per pt year for MV and 0.27% for AV
Medical treatment : in late PVE and in nonstaphylococcal infections
Surgery: failure of medical treatment; hemodynamically significant
prosthesis regurgitation, especially if associated with deterioration of
LV function; large vegetations; and development of intracardiac
fistulas
Piper et al. Heart 2001;85:590–593
Intravascular hemolysis in patients with new-generation
prosthetic heart valves: A prospective study
434 pts 1997-1998, Italy
Mild degrees of intravascular hemolysis common in normal
functioning prostheses (50-95% of mechanical)
26% in these series
Higher in double valve replacement
mitral position
Absence in stentless aortic bioprostheses
Low incidence in stented aortic bioprostheses
!!!TEE for early detection of subclinical periprosthetic leaks
Mecozzi et al. J Thorac Cardiovasc Surg 2002;123:550-6
Risk factors for valve-related complications after mechanical valve
replacement in 505 pts with long-term follow up
Carbomedics 505 pts 1988-2005, France
Implantation in the mitral position
Risk factors for bleeding
unstable INR
history of thromboembolic or bleeding events
The use of antiplatelet agents proved to be a protective factor
against thromboembolic events.
Bourguignon et al. The Journal of Heart Valve Disease 2011;20:673-680
STS NATIONAL DATABASE – SAMPLE DATA 2009
AVR
mechanical 14%
Mean age 68.4 yrs
60yrs <50%< 79yrs
4.7% endocarditis – 70% elective
Operative mortality 3%
In-hospital mortality 2.6%
Anticoagulation complications 1.7%
bioprosthetic 85%
MVR
bioprosthetic 65%
mechanical 34%
Mean age 62.3 yrs
53yrs <50%< 73yrs
19% endocarditis – 59% elective
Operative mortality 5%
In-hospital mortality 4.7%
Anticoagulation complications 2.4%
http://www.sts.org/sts-nationaldatabase/database-managers/adult-cardiac-surgerydatabase/adult-cardiacsurgery-database
BIOLOGICAL VERSUS MECHANICAL
Aortic or mitral position (worse survival in MVR)
Isolated first time or double or reop
Large series – retrospective / prospective
Operating time frame (surgical and valve design evolution)
Infective endocarditis
(not appropriate to generalize – different
baseline and evolution of disease)
Edinburgh Heart Valve Trial
Veterans Affairs Cooperative Study on Valvular Heart
Disease
(Randomized trials)
Different era of surgical technique
Compared prosthetic valves that are no longer implanted
Outcomes 15 yrs after valve replacement with a
mechanical vs a bioprosthetic valve: final report of the
Veterans Affairs Randomized Trial
Hancock vs Bjork-Shiley 575 pts 1977-1985 Colorado, Arizona, Illinois,California
Mortality – lower for mech AVR (66% vs 79%, p < 0.02)
Primary valve failure in pts <65 yrs
bio vs mech, 26% vs 0%, p<0.001 for AVR
44% vs 4%, p=0.0001 for MVR
Reoperation - higher for bioprosthetic AVR (p =0.004)
Bleeding - more frequently in pts with mechanical valve
Thromboembolism - similar
Valve-related complications - similar
Hammermeister et al. J Am Coll Cardiol 2000;36:1152– 8
Twenty year comparison of a Bjork-Shiley mechanical
heart valve with porcine bioprostheses
Porcine bioprosthesis vs Bjork-Shiley 541 pts 1975-1979, Edinburgh
No difference in survival
Improved survival for mech with the original prosthesis
intact after 8–10 yrs for MVR and 12–14 yrs for AVR
Increased reoperation for porcine bioprosthesis
Bleeding more common in mechanical
No difference in thromboembolism and endocarditis
Oxenham et al. Heart 2003;89:715–721
Twenty-year comparison of tissue and mechanical valve
replacement
Hancock-Carpentier vs mech St Jude 2533 pts 1976-1992, California
Multivariable analysis - type does not affect survival
Analysis by age or CAD - similar long-term survival
Risk of hemorrhage - higher only in mech AVR
Thromboembolism rates - similar
Reoperation rates - higher in tissue/ increase with time
Valve complications - higher in mech AVR
- cross over in tissue after 7yrs for
MVR and 10yrs for AVR
Khan et al. J Thorac Cardiovasc Surg 2001;122:257-69
AVR
MVR
Khan et al. J Thorac Cardiovasc Surg 2001;122:257-69
Risk-corrected impact of mechanical vs bioprosthetic on
long-term mortality after AVR
Large metaanalysis in 17439 pts
mechanical and biologic valve
mean age
(58 vs 69 yrs)
mean follow-up
(6.4 vs 5.3 years)
CABG
(16% vs 34%)
endocarditis
(7% vs 2%)
death rate
(3.99 vs 6.33 %/pt-year)
Death rate corrected for age, NYHA class III and IV, and
CABG left valve type with no effect.
Lund et al. J Thorac Cardiovasc Surg 2006;132:20-6
bioprosthetic valve series mean age of 71 to 74 years
thromboembolism varied from 1.40% to 6.45% per pt-year.
bleeding rates ranged from nearly nothing to 1.18%/pt-year
Dogma that biological valves are not thrombogenic and do not
require AC treatment
BUT a bioprosthetic valve does not protect
1. from the “normal occurrence” of gastrointestinal, urogenital,
and cerebral bleeding
2. from the “background rate” of stroke
3. from requiring oral AC treatment for the usual (nonprosthetic
valve) indications, and more than 20% of pts have been
reported to be taking oral warfarin at a mean of 2.6 to 5.8
years after AVR
Lund et al. J Thorac Cardiovasc Surg 2006;132:20-6
AVR: a prospective randomized evaluation of mechanical vs
biological valves in patients ages 55 to 70 yrs
Carpentier vs St Jude-Carbomedics 310 pts 1995-2003, Italy
No difference in the survival rate at 13 years
Valve failure more frequent in bio (p=0.0001)
Reoperation more frequent in bio (p=0.0003)
Thromboembolism - similar
Bleeding - similar
Endocarditis - similar
Valve-related complications - similar
Stassano et al. JACC 2009;54;1862-1868
Treatment of Endocarditis With Valve Replacement: The Question
of Tissue Versus Mechanical Prosthesis
1964-1995 306 pts (209 NVE
97 PVE)
Operative mortality 18%
Survival 44±5% NVE
16±7% PVE at 20 yrs
Moon et al. Ann Thorac Surg 2001;71:1164 –71)
Age >60 yrs
For pts < 60yrs, overall long-term
survival was similar in those who
received a mechanical or a biologic
valve
Age <60 yrs
Moon et al. Ann Thorac Surg 2001;71:1164 –71)
In younger patients, the long-term
reoperation rate was higher with
bioprosthetic valves than with
mechanical, but, as patient age
increased, the freedom from
reoperation rates converged.
Age >60 yrs
Age <60 yrs
Mechanical valves are more
suitable for younger pts
with NVE
Moon et al. Ann Thorac Surg 2001;71:1164 –71)
AVR for active infective endocarditis: 5-year survival comparison of
bioprostheses, homografts and mechanical prostheses
1998-2000
167 pts
PROSPECTIVE STUDY
Nguyen et al. European Journal of Cardio-thoracic Surgery 37 (2010) 1025—1032
5 yr death rate hazard ratio
Nguyen et al. European Journal of Cardio-thoracic Surgery 37 (2010) 1025—1032
• outcome affected by prosthetic valve hemodynamics,
durability, and thrombogenicity
BUT
complications can be prevented or impact minimized by
•
•
•
•
optimal prosthesis selection
modifiable risk factors
careful medical management after implantation
careful follow-up after implantation
Pibarot et al. Circulation 2009, 119:1034-1048
SELECTING PROSTHETIC VALVE
1. Patient’s age
2. Patient preference
3. Life expectancy
increasing to 17 yrs for a 65-year- old white man in US
mortality from chronic debilitating or fatal diseases in elderly
long life span makes SVD almost inevitable in elderly
4. Contraindication for warfarin
5. Comorbidities
In favor of mechanical valve
(1) preference of a mechanical valve, no warfarin contraindication
(2) already on anticoagulation
(3) at risk of accelerated SVD (young, hyperparathyroidism, renal
insufficiency)
(4) <65 yrs of age and long life expectancy
In favor of bioprosthesis
(1) preference of bioprosthesis
(2) good-quality anticoagulation is unavailable (contraindication or
high risk,compliance problems, lifestyle)
(3) >65 yrs of age and/or limited life expectancy
(4) woman of childbearing age