Transcript INFECTIVE ENDOCARDITIS

INFECTIVE
ENDOCARDITIS
Manoj Kuduvalli
Definition
Bacterial or Fungal infection
within the heart (although
chlamydial and rickettsial
infections are known) ; the role
of viruses is unknown
ORIGINAL
CLASSIFICATION
(Prior to Antibiotic era)
Infective Endocarditis
Acute
Subacute
Virulent Organisms
Normal Valve
Death < 6 weeks
Relatively avirulent organisms
Abnormal valve
Indolent course
Current Criteria for Classification
Underlying Anatomy:
› Native Valve Endocarditis
› Prosthetic Valve Endocarditis
Infecting Organism
› Serves as basis for therapy and
prognosis
Native Valve Endocarditis
Underlying Predisposing Conditions
›› 60 - 80% of non IV Drug abusers have a
predisposing condition
› Mitral Valve Prolapse
30 - 50%
› Rheumatic Heart Disease 20 - 40%
› Degenerative Aortic and 20 - 30%
Mitral valve disease
› Congenital Heart Disease 10 - 20%
Native Valve Endocarditis
Microbiology
›› Streptococci
Viridans Streptococci
›› Staphylococci
50 - 70%
(50% of all Strep)
~ 25%
Mostly Coagulase +ve Staph. Aureus
Staph. Epidermidis
›› Enterococci
~ 10%
Native Valve Endocarditis
Microbiology
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Viridans Streptococci
Infect primarily abnormal
valves
Indolent clinical course
Highly sensitive to Penicillins
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Staph. aureus
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Infect normal and abnormal
valves
Fulminant course with rapid
destruction of valves and
multiple metastatic abscesses
Mostly resistant to Penicillins
and sensitive to penicillinase
resistant ß-lactams
Common with soft tissue
infections, and infected IV
catheters
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Native Valve Endocarditis
Microbiology
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Staph. Epidermidis
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Enterococci
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Indolent Course
Affects abnormal valves
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Normally affects
damaged valves
Recent history of
genitourinary or
gastrointestinal
manipulation, disease or
trauma
Usually sensitive to
Penicllin+Gentamicin
Resistant strains
prevalent
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Prosthetic valve endocarditis
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5 - 15% of all Infective Endocarditis
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Overall incidence 1 - 4%
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Risk of PVE peaks at 15 days postop. ,
then rapidly declines by 150 days
Prosthetic Valve Endocarditis
Classification
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Early ( < 60 days )
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Late ( > 60 days)
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Reflects perioperative
contamination
Incidence around 1%
Microbiology
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After endothelialization
Incidence 0.2 -0.5 % / pt. year
Transient bacteraemia from
dental, GI or GU
Microbiology
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– Staph (45 - 50%)
» Staph. Epiderm (~ 30%)
» Staph. Aureus (~ 20%)
– Gram -ve aerobes (~20%)
– Fungi (~ 10%)
– Strep and Entero (5-10%)
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– resembles native valve
endocarditis
IE in IV Drug Abusers
Right sided predilection
Tricuspid Valve
~ 55%
Aortic Valve
~ 25%
Mitral Valve
~ 20%
Pulmonary Valve
1 - 1.5%
Mixed Rt. And Lt. Side 5 - 6%
IE in IV Drug Abusers
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Skin most predominant source of infection
Also contamination of drugs and paraphernalia
70 - 100% of Rt. sided IE results in pneumonia
and septic emboli
Microbiology
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Staph aureus
Streptococci and Enterococci
Gram -ve bacilli
Fungi (Candida and Aspergillus
~60%
~20%
~10%
~5%
IE in adults with congenital
heart disease
Common defects
VSD
Bicuspid AV
PDA
PS
Coarctation of Aorta
Occurs in defects with
--mild or no hemodynamic consequences
--high gradients
--high velocity jets impinging on endocardium
Microbiology very important since
virulence of the infecting organism
is a significant factor in
determining the success rates of
both medical and surgical
treatment
Pathogenesis
Requires interaction between
› Host vascular endothelium
› Host haemostatic response
› Adventitiously circulating
organisms
Pathogenesis of Vegetations
Hemodynamic factors
predisposing to Infective
Endocarditis
 High
velocity abnormal jet stream
 Flow from high to low pressure
chamber
 Narrow orifice between two
chambers creating pressure gradient
Pathology
Local intracardiac
infectious process
Embolization
Immune complex
associated disease
Pathology
Intracardiac
infections
Leaflet
perforation
Rupture of
chordae
Valve ring
abscesses
Burrowing
abscesses
VSD
Conduction
abnormalities
Purulent
pericardial effusions
Fistulae
Aneurysm of
Sinus of Valsalva
Common sites of origin of extravalvular spread
Pathology
Initially affects
Valve leaflets in
native valve
endocarditis
Can extend into
annulus
Annulus in prosthetic
valve endocarditis
Due to presence of
sewing rim
Pathology 
Incidence
– Clinically
– Pathologically
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Embolic Phenomena
15 - 45%
45 - 65%
More with large mobile vegetations
– Fungi (Candida and Aspergillus)
– Group B and G Streptococci
– Staph aureus
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Result in
– Infarcts
– Abscesses
– Mycotic aneurysms
Pathology
Immune Complex Associated
 Glomerulonephritis
 Arthritis
 Osler’s
nodes
Clinical Features
Onset usually within 2 weeks of infection
› Indolent course
- Malaise
- Fatigue
- Night sweats
- Anorexia
- Weight loss
› Explosive course
- CCF
- S/o severe systemic sepsis
Clinical features
› Fever
- Usually < 39 °C, remittent
- May be absent in
- elderly
- severe debility
- CCF
- Already on antibiotics
› Murmurs
- Appearance of new murmur or true
change in existent murmur indicates
infection with virulent organism
Other Clinical Features
Splenomegaly
 Petechiae
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–
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~ 30%
20 - 40%
Conjunctivae
Buccal mucosa
palate
skin in supraclavicular regions
Osler’s Nodes
10 - 25%
 Splinter Haemorrhages
5 - 10%
 Roth Spots
~ 5%
 Musculoskeletal (arthritis)
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Complications
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Congestive Cardiac Failure (Commonest
complication)
» Valve Destruction
» Myocarditis
» Coronary artery embolism and MI
» Myocardial Abscesses
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Neurological Manifestations (1/3 cases)
» Major embolism to MCA territory
» Mycotic Aneurysms
~25%
2 - 10%
Complications
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Metastatic infections
– Rt. Sided vegetations
» Lung abscesses
» Pyothorax / Pyopneumothorax
– Lt. Sided vegetations
»
»
»
»
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Pyogenic Meningitis
Splenic Abscesses
Pyelonephritis
Osteomyelitis
Renal impairment d/t Glomerulonephritis
Diagnosis
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Blood Cultures
– Positive in 95% cases
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Other Laboratory Parameters
– Anaemia
– Leucocytosis (WCC may be normal in indolent
infection)
– Thrombocytopenia
–  ESR (may be absent in CCF and renal failure)
– Urine - Microscopic hematuria / proteinuria
Echocardiography
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Can demonstrate lesion / vegetation in 60 80% of cases
Difficult in prosthetic valve endocarditis
TOE better than TTE
Can demonstrate
– Morphology of valve
– Annular abscesses
– Hemodynamics of the valves
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Serial observations can contribute to decision
for surgery
Treatment
Medical
Surgical
Principles of Medical
Management
Sterilization of Vegetations with antibiotics
- prolonged
Slowly metabolising bacteria
due to high density, hence 
sensitivity
- high dose
Bacteria deep inside
vegetations
-bactericidal
Principles of Medical
Management
Acute onset, fulminant
-Within two to three hours of
clinical diagnosis.
-Take cultures, but do not wait
for results
Timing of Therapy
Subacute onset, or having
received recent antibiotic
-Within two to three days.
-Can wait for culture reports
Principles of Medical Management
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Isolation of organisms very important
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Therapy before isolation of organism
» Native valve endocarditis and in IV drug
abusers
 Directed
against Staph aureus
» Prosthetic valve endocarditis
 Broad
spectrum antibiotics directed against
– Staph aureus
– Staph epidermidis
– Gram –ve bacilli
Indications for Surgery
Left sided native valve endocarditis
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Valvular disruption leading to severe
insufficiency and CCF
Extravalvar extension
Embolization of vegetations
Failure of medical management
Positive blood culture and systemic signs of
infection after “adequate” antibiotic therapy
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Resistant organisms
such as MRSA, Fungi , Pseudomonas
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Echo detected vegetation > 1 cm ??
Indications for Surgery
Right sided native valve endocarditis
Indications differ because:
- Consequences of valve disruption and emboli are less
- Success with antibiotics seems to be better
--Failure of medical treatment
--CCF, with its complications
Indications
(elective)
--Recurrent pulmonary emboli
with complications
--Extravalvar spread (rare)
Indications for surgery
Prosthetic valve endocarditis
Early infection almost always require
surgery
 Late infection
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Antibiotic therapy succeeds more often with
Bioprosthesis compared to mechanical valves
CCF due to prosthesis
dysfunction
Indications
Multiple emboli
Persistent infection
Indications for Surgery
Special situations
AIDS
Not usually indicated since life
expectancy due to AIDS very poor
HIV +ve patient without AIDS
IV Drug Abusers
No change in indications since enough
number survive > 10 years
When to operate ?
As soon as there is a major indication
Valid reasons for delay
Acute CNS injury
--Hemorrhagic infarct (Wait for
10 days to allow healing)
--Coma (very poor prognosis )
Renal failure due to Glom’nephritis
Follow through the acute phase
(Prerenal failure -- early operation)
Principles of operation
Repair or Replacement ?
(More important with mitral valves)
Repair contemplated only if:
--Infection well controlled
--Repair structurally feasible after
involved tissue excised
Principles of operation
Early operation once indicated
 Preop. knowledge of morphology of valve
 Good exposure (may be difficult in
mitrals)
 Excision and debridement of all infected
or involved tissue even if extensive
reconstruction or permanent pacing
required
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Principles of operation
Look for extravalvar extension
 If present, evacuate abscess cavity and
repair with biological material such as
autologous or bovine pericardium
 Suture valve onto clean and relatively
strong tissue
 Temporary pacing leads
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Stented
Bioprosthesis
Mechanical
Which
Prosthesis?
Stentless
Bioprosthesis
Homograft
Choice of prosthesis
Important factor is location of infection
-- Infection of cusps only:
Choice does not matter, since all infected
tissue is usually excised
-- Perivalvar extension:
No choice between mechanical and stented
bioprosthesis (both with cloth sewing rims)
Homograft, maybe stentless bioprosthesis
have lesser incidence of infection
Choice of prosthesis
Mechanical v/s Bioprosthetic
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No difference in linearized rates for recurrent
or residual infection (~1-2% per patient year)
No difference in operative mortality and
complication free survival
Infected bioprosthesis more easily sterilized
(since infection initially involves leaflets)
However, infection in bioprosthesis may hasten
SVD due to damage to leaflets
Choice of prosthesis
Homograft v/s others
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Hazard function for recurrent
endocarditis has only low constant phase
and has no high early hazard phase like
other prosthesis
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Homograft best choice if valved conduit
is required for root replacement ( > 50%
annular dehiscence or aortoventricular
discontinuity)
Postoperative Antibiotics
To continue for 6 weeks if
› Operated for --Acute fulminant infection
--Failure of medical therapy
--Resistant organisms
› Excised valve yields positive cultures
› Periannular involvement
› Valve culture –ve, but organisms seen on
histology
› Positive blood cultures 3 – 4 days postop.
Results of Treatment
Native valve endocarditis
Medical Management
Mortality 10 – 60 %
Risk Factors
Virulent organisms s/a MRSA, G-ve bacilli, fungi
CCF
Persistence of systemic sepsis
Major septic embolus
Extravalvar extension
Acute renal failure
Results of Treatment
Native valve endocarditis
Surgical Management
Hospital Mortality 5 – 20%
Risk factors
Virulent organisms
Perivalvar extension
Intractable CCF
Renal and multiorgan failure
Results of Treatment
Native valve endocarditis
Surgical Management
Recurrent Endocarditis ~ 2%
Most occurs within 2 months post op.
Same organism
No fresh source of infection
Perivalvar leaks 3-7%
Results of Treatment
Prosthetic valve endocarditis
Medical Management
Mortality ~ 70%
Risk factors
Valve incompetence or perivalvar leak
Early postoperative onset
Virulent organism
Results of Treatment
Prosthetic valve endocarditis
Surgical Management
Hospital Mortality 0 –22%
Risk factors
Early postoperative infection
Virulent organism
Perivalvar extension
Delay in operation
Results of Treatment
Prosthetic valve endocarditis
Surgical Management
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Long term results differ from valve
replacement for NVE or other lesions
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Have comparatively unfavourable rates
of late death, recurrence of infection and
reoperation
Antibiotic Prophylaxis
Protocol usually followed recommended by Dajani et al in
JAMA 1990
Recommended in following conditions
Prosthetic valves
Previous history of infective endocarditis (even without
underlying heart disease)
Most congenital heart diseases
Rheumatic or other acquired valve disease
IHSS
MVP with MR
Thank you!