Edward Evans MD FACC Desoto Heart Clinic Disclosures • Medtronic: • St. Jude Medical: speaker speaker.

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Transcript Edward Evans MD FACC Desoto Heart Clinic Disclosures • Medtronic: • St. Jude Medical: speaker speaker.

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Edward Evans MD FACC
Desoto Heart Clinic
Disclosures
• Medtronic:
• St. Jude Medical:

speaker
speaker


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Year

Surgeon

Description

Valvular Surgery

1960

Dwight Harken

1st successful aortic valve replacement
(AVR). A caged ball valve was used

1960

Starr and
Edwards

1st successful mitral valve replacement
(MVR) using caged-ball valve of their own
design.

1960-67

Approx. 2000 Starr-Edwards valves
implanted

1962

Heimbecker

Toronto. 1st clinical implant of an aortic
hemograft valve.

1962

Daniel Ross

1st successful aortic valve homograft
implant

1964

Duran and
Gunning

Aortic valve replacement with xenograft
porcine aorti valve (formaldehyde-fixed
xenografts->tissue degradation and
calcification).

1971

Carpentier

Xenograft valves fixed with
glutaraldehyde and mounted on a stent
to produce a bioprosthesis


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4

1858 - Improved bottle stopper conceptual impetus for the first successful ball
and cage design


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1960s - Commercially Available Valves

• Caged-ball valves were
improved and became
commercially available
1960: Harken implanted a double-cage ball
valve into aortic annulus

1960: first implant of the Starr-Edwards
valve - mitral position (first sold in 1965)

5


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Prosthetic Heart Valve
Management


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Prosthetic Heart Valve
Management





Post-operative surveillance
Prevention of infection
Prevention of thrombosis
Management of complications


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Surveillance
• Initial post-op visit:
– H&P, CXR, EKG –class 1
– 2D echo – class 1
if unsatisfactory…other studies
– Labs: CBC, INR


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Surveillance
• Later visits: (patients without
complications)
– Routine follow-up yearly. Earlier if
clinical change—Class I
– Routine serial echo—Class IIb
• Echo if change in exam
• New regurgitation—echo every 3-6
months.


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Prevention of Infection
• Class I
• Class I
• Class I
– 2% risk of infection at 14 days with no
prophylaxis.

• Dental procedures
• Invasive Respiratory procedures with
incision or biopsy
• Surgery involving infected skin or
musculoskeletal tissue


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Prevention of Infection
30-60 min before procedure

• Amoxicillin 2g PO/Ampicillin 2g
IV/IM
• Cephalexin 2g PO
• Azithromycin 500mg PO
• Clindamycin 600mg PO or IV
• Cefaxolin or Ceftriaxone 1g IV/IM


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Anticoagulation
• Mechanical valves:
– Risk of thromboembolic event
• Untreated: up to 8% per year
• Treated: less than 2% per year

– Mitral greater risk than aortic
– Higher risk early post-operatively

• Bioprosthetic valves:
– 0.7% per year risk


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Anticoagulation
• All valves require anticoagulation
– Duration
– Agent(s)

• Valve type and position
• Patient risk factors





Atrial fibrillation
Previous thromboembolic event
Hypercoagulable state
Low EF < 30%

• Contraindications


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Anticoagulatioin
• Aspirin 75-100mg daily
– All patients – class 1
– Use alone with bioprosthetic AVR and
MVR with no risk factors

• Coumadin (INR 2.0-3.0)
– Mechanical AVR bileaflet, no risk
factors
– Bioprosthetic
• First 3 months – class 2a
• Long term with risk factors.


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Anticoagulation
• Coumadin (INR 2.5-3.5)
– All others
• Starr-Edwards run higher >3.0


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Anticoagulation
• Events while at target:
– INR 2-3: increase to 2.5 to 3.5
– INR 2.5-3.5: increase to 3.5 to 4.5

• Short term interruption:






Bileaflet AVR no risk factors: No bridge
Bridge all others with UFH
LMWH is class 2b
FFP in emergencies
No vitamin K


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Complications






Structural valve deterioration
Non-structural Valve Dysfunction
Thrombosis and Embolism
Valvular endocarditis
Hemolysis


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Structural Valve Dysfunction


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Structural Valve Dysfunction
Mechanical
• Primary failures rare now. Led to
discontinuation of certain valves
• Now mainly valve ring-tissue
interface
• Mechanisms:
– Valve dehiscence
– Perivalvular regurgitation
– Tissue in growth (pannus) and
thrombosis


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Structural Valve Dysfunction
Bioprosthetic
• Incidence 20-30% at 10 years, 50%
at 15 years
• Tissue degeneration
• Secondary calcification
– Stenosis increasing after 6 years
– More likely with MVR, youth,
pregnancy, and chronic renal failure

• Perforation
• Perivalvular regurgitation


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Nonstructural Valve
Dysfunction
• Clinically significant obstruction in
the setting of normal prosthetic
function
• Patient prosthetic mismatch
• Occurs mostly in older women
• Thrombus and Pannus


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MILD/NONE
(non significant)

MODERATE

SEVERE

0.65

0.85
Indexed EOA
(cm2/m2)


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Combined Impact of PPM and LV
Dysfunction on Short-term Mortality

80

67%

60

P<0.001

40
20
0

16%

7%
P=0.05

3%
Non
significant

P<0.00
1

5%

23%

P=0.0
8

P<0.00
1

Moderate

Severe


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Thrombosis and Embolism
• Incidence 0.6% to 2.3% per patient
year
– Anticoagulated mechanical rate same as
unanticoagulated bioprosthetic
– Mitral position greater risk than aortic
– Tricuspid greatest risk

• Intrinsic thrombogenicity of valve
materials, flow turbulence and
stagnation, shear stresses, risk factors


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Valve thrombosis
• Echo, TEE, Fluoroscopy, MRI/CT
• Thrombolysis





70-90% effective
Mortality 4-12% acutely
Better for right sided valves
Duration < 24hours

• Surgery
– Class 2a for large clot, NYHA 3-4
– Class 1 small clot, failure or
contraindications to lysis


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Embolism
• Mechanical valves
– No anticoagulation: 4% per year
– Aspirin: 2% per year
– Coumadin (therapeutic) 1% per year
– Mitral valves twice the risk of aortic
valves


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Prosthetic valve endocarditis
• Yearly risk 0.5% despite prophylaxis
• Highest risk MVR
• No difference mechanical and
bioprosthetic
• Risk greatest in first 6 months
• Usually involves the valve ring
• Substantial mortality


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Prosthetic Valve Endocarditis
• Medical
– Hospitalize at CV surgery center
– Delay antibiotics until organism
identified
– TEE
– Prolonged antibiotics with ID guidance

• Surgery
– Heart failure, abscess, dehiscence,
relapsing infection, failed antibiotic


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Macroangiopathic hemolytic
anemia
• Anemia post operatively






Microcytic
Increased LDH
Decreased haptoglobin
NO suspicion of ITP/TTP
Schistocytes

• May lead to heart failure
• Transfusion dependent anemia
• Potential need for re-do valve surgery


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Summary
• Prosthetic valves are not a cure for
valvular disease
• Associated with large number of
potential medical management
issues
• Careful post-operative valvular
surveillance is important


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Questions?