Endocarditis
Heather Patterson
PGY-2 EmergJune 6 2007
Objectives
• History and Epidemiology• Pathophysiology• Risk Factors• Duke Criteria• Management
History
• 1825: First described • 1846: Realized vegetations where
bacterial• 1932-40: Supportive treatment until this
time when ABx first used
Epidemiology
• 10,000-50,000 new cases per year in US• Mean age 55y• M:F = 2:1 – 9:1• Rheumatic heart disease less common
than nosocomial, prosthetic valve, IVDU
Epidemiology
• Native Valve:– >50yo– M>F– 60-80% with predisposing cardiac disease– Staph aureus in 50-60%
Epidemiology
• IVDU:– 20% have
abnormal underlying valve pathology
– R vs L
Pathophysiology
• Thrombus formation:– Subacute - often
thrombus is preexisting or damage to valve is preexisting
– Acute – bacteria can cause thrombus, +/- prior valve damage, rapid progression
• Organism Adherence– Circulating
bacteria/fungus adhere and colonize
– Accelerated plt aggregation
– Platelets coat and protect bacteria from immune response
Pathophysiology
• Valve Invasion:– Immune response
damages valve leaflets, chordae tendinae
• Systemic effects:– Infectious
microemboli• CNS• Myocardium• Renal• Pulmonary
– Vasculitis
Microorganisms
• Congenital valve disease & MVP:– Strep viridans– Strep milleri
• IVDU & prosthetic valves– Coag neg staph
• Other– Gram neg bacilli
• HACEK—haemophilus, actinobacillus, cardiobacterium, eikenella, kingella
– Candida– Aspergillus
Risk Factors
• IVDU– R vs L sided?– Recurrence up to
40%
• Prosthetic heart valves– First yr- 1-4%
develop IE– 0.5-4% risk each
subsequent year– Type of valve not a
determinant of risk
• Pacemakers/ICDs
• Indwelling caths
• History of IE– 2.5-9% of pts recur
Risk Factors
• Structural heart disease– Up to ¾ of all IE have structural disease
present at the time of diagnosis– Rheumatic:
• Older studies show this is the most common
– Mitral value prolapse with regurgitation• 5-8x the risk of general population• Reported in 22-29% of cases
– Aortic valve disease• Reported in 12-30% of cases
Risk Factors
• Congenital Heart Disease– Seen in 10-20% of IE cases– Most common lesions:
• Bicuspid aortic valve• PDA• VSD• Coarctation• TOF
Risk Factors
• 2401 pts followed for 40,000 days• Rates of IE in patients with AS, PS, VSD• Results:
– Overall incidence was 35x the general population rate
– AS• Risk increased with gradient across the valve
– PS:• Lowest risk of the conditions studied. (1/592
patients)
– VSD• Size of defect not related to risk of IECirculation 1993 Feb;87(2 Suppl):I121-6.
Duke Criteria
• Any one of the following:– Direct evidence of IE on histologic exam– Gram stain/cultures of specimens– Two major criteria– One major and 3 minor criteria– Five minor criteria
Duke Criteria
• Major criteria– Positive blood cultures
x2 (12 hours apart)• Strep viridans• Strep bovis• HACEK group• Community acquired
Staph or entercoccus
– Persistent bacteremia by cultures >12h apart
Duke Criteria
• Major criteria– Evidence of endocardial
involvement with new murmur
• Single positive culture for Coxiella burnetti OR Antiphase 1 IgG Ab titre >1:800
Duke Criteria
• Major criteria– Positive ECHO
• Oscillating intracardiac mass on valve or supporting structures, regurgitant jets or prosthetic material
• New partial detachment of prosthetic valve
• New valvular regurgitation or increase or change
• Abscess
NOTE: TEE recommended for prosthetic valves
Duke Criteria
• Minor criteria– Predisposing cardiac disease– IVDU– Fever>38– Vascular phenomena
• Arterial emboli• Septic pulmonary infaracts• Mycotic aneurysms• Intracranial hemorrhage• Conjunctival hemorrhage• Janeway lesions
Duke Criteria
• Minor criteria– Immune phenomena
• Osler’s nodes• Roth spots• Positive rheumatoid factor• Glomerulonephritis
– Microbiological evidence• Positive culture not meeting major criteria• Serologic evidence of active infection with organism
that causes IE
– ECHO• Non diagnostic but abnormal
Duke Criteria
• Sensitivity: 99%• Specificity: 95%
Clinical Presentation
• Most often nonspecific and varied presentation– High index of
suspicion
• Classic triad:– Fever– Anemia – Murmur
• Most common symptoms:– Intermittent fever
(85%)– Malaise (95%)
• Others: – Weakness,
anorexia, myalgias
– SOB, CP, cough, – HA, neuro
symptoms
Investigations
• CBC– Leukocytosis– Mild anemia
• Elevated ESR, CRP• Blood culture x 3-4 • U/A:
– microscopic hematuria (secondary to emboli)
• EKG– conduction
abnormality possible if abscess develops
• ECHO– TTE: Native valve– TEE: Recommended
for prosthetic valves• superior to TTE; NPV
95%
Management
Vanco 15mg/kg then 500mg q6h
AND
Gent 1-3mg/kg then 1mg/kg q8h
Ceftriaxone 1-2g q12h AND
Gent 1-3mg/kg then 1mg/kg q8h
OR
Management
• Surgical Indications:– Severe CHF due to valve incompetence– Paravalvular leak around prosthetic valve– Fungal endocarditis– Persistent bacteremia despite abx