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