Transcript INFECTIVE ENDOCARDITIS and valvular vegetations

INFECTIVE ENDOCARDITIS
and valvular vegetations
Alex Yartsev 30/03/2010
Pathological definitions
INFECTIVE ENDOCARDITIS
• The colonization or invasion of heart valves or
the mural endocardium by a microbe
VEGETATIONS
• Masses of thrombotic debris and organisms,
attached to valves or myocardial tissue, and
destructive to that tissue
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
A vegetation
Subacute Mitral
Endocarditis,
Strep viridans
Acute endocarditis of
congenitally bicuspid aortic
valve, by Staph aureus
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
Acute IE or Subacute IE?
• Definition dependent on virulence and course
ACUTE: 10-20% of cases
• Infection of a normal valve
• Rapidly progressing, usually Staph Aureus
• Rapidly destructive, necrotising, ulcerative
SUBACUTE – 80-90% of cases
• Infection of a previously diseased, deformed valve
• Slowly progressing, usually Streptococcus
• Gradually destructive, more like erosive
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
There are 3 main pathogens
Defective valves:
– 60% of cases its Streptococcus viridans
Normal valves
– Staph Aureus especially if the valve belongs to an IV drug user
Prosthetic valves:
- Staph epidermitis
OTHER ORGANISMS: Enterococci, Haemophilus, Actinobacillus,
Cardiobacterium, Eikenella, Kingella… All oral organisms
In 10-15% of cases, no organism is found.
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
A Word About Streptococci
• Alpha hemolytic: reduce iron from hemoglobin
– Strep pneumoniae, Strep viridans
• Beta hemolytic: lysis of whole RBCs
– Group A: S.pyogenes  rheumatic fever
– Group B: S.agalactiae  neonatal meningitis
– Group C: S.equi  “distemper of horses”
– Group D: Enterococci
– Group G: S.canis  dog saliva
Predisposing factors
FOREMOST:
Anything that predisposes to bacteraemia
Dental procedures, oral infections,IV drug use,
surgery, IV cannulas, central lines,
huge obvious infections elsewhere, or minute
trivial areas of slightly broken skin
Predisposing factors
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Rheumatic heart disease
Mitral valve prolapse
Degenerative calcific valvular stenosis
NORMAL bicuspid aortic valve
Prosthetic valves
Unrepaired and repaired congenital defects
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
Complications
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Brain abscess
Lung abscess
Heart failure
Glomerulonephritis (immune complexes)
Emboli  anywhere
Common clinical Features
• Fever, chills, rigors
• New heart murmr
• New onset of heart failure signs/symptoms
Problems otherwise unexplained:
• Brain abscesses
• Lung abscesses
• Glomerulonephritis
Uncommon clinical features
• Roth spots
(Retinal hemorrhages)
• Janeway lesions
(painless microabscesses )
Oslers nodes
(painful immune complex deposits)
Robbins and Cotran Pathologic Basis Of Disease (8th ed)
Tally and O’Connor
Populations at risk
• IV drug users: usually tricuspid valve
• Valve replacement patients
• Patients with repaired or unmanaged septal
defects
• Past history of rheumatic heart disease
Preventative measures
• COCHRANE:
“There remains no evidence about whether
penicillin prophylaxis is effective or ineffective
against bacterial endocarditis in people at risk
who are about to undergo an invasive dental
procedure. “
Diagnosis
• Duke criteria: MAJOR citeria
– Streptocucus viridans in blood culture
– Staph aureus in blood culture in absence of
primary focus
– Persistently positive blood culture: organism
consistent with infective endocarditis from
• Blood cultures drawn more than 12 hours apart, or
• all of three, or majority of four or more separate blood
cultures, with the first and last drawnat least 1 hour
apart
– Evidence of Endocardial involvement: +ve ECHO
Diagnosis: Duke Criteria
Need 2 major
Or 1 major and 3 minor
Or 5 minor criteria
• MAJOR CITERIA
– Positive blood culture, for a characteristic organism
– Echo identification of a valvular mass or partial separation
of an artificial valve
Diagnosis: Duke Criteria
• MINOR CITERIA
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Predisposing heart lesion
IV drug use
Vascular lesions eg. splintr hemorrhages or petechiae
Immunological phenomena eg. Oslers nodes, Roth spots
Single culture positive for an unusual organism
Echo findings consistent with but not diagnostic of
endocarditis
TTE or TOE?
• TTE for aortic valve
• TOE for mitral, pulmonary, tricuspid
• TTE less sensitive for vegetations than TOE
Practical Management
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Delay of diagnosis = lower survival
Three sets of cultures before antibiotics;
Then, commence empiric therapy
Continue for 6 weeks
Ohs Intensive Care Manual 6th ed; Therapeutic Guidelines
Empirical antibiotics
• Therapeutic Guidelines suggest:
– Benzylpenicillin 1.8 g q4h,
PLUS
– Flucloxacillin 2g q4h
PLUS
– Gentamicin 6mg/kg daily
ALSO
– Add Vancomycin if the pt has a prosthetic valve or the
infection is hosptial-acquired
Good Evidence
• COCHRANE:
“There remains no evidence about whether
penicillin prophylaxis is effective or ineffective
against bacterial endocarditis in people at risk
who are about to undergo an invasive dental
procedure. “
Most people still use ampicillin or clindamycin
Antibiotics for the prophylaxis of bacterial endocarditis in dentistry: Oliver et al, 2008