Infective Endocarditis and Rheumatic Heart Disease Flashcards by Chloe Mackle

What is infective endocarditis?

Infection of the endocardium (inner layer of the heart)

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What structures might be infected by infective endocarditis?

Heart valves
Interventricular septum
Chordae tendinae
Intra-cardiac devices

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What is the change in the incidence and mortality of infective endocarditis in the last 30 years?

No change in either

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What is the general prognosis and mortality of infective endocarditis?

Poor prognosis

High mortality

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What factors affect the prognosis and morality from infective endocarditis?

Underlying cardiac disease
Micro-organism involved
Presence of complications
Patient characteristics

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What professions are involved in the collaborative approach to treating infective endocarditis?

Primary care physicians 
Acute medicine 
Cardiologists
Surgeons 
Microbiologists
Infectious disease 
Neurologist
Neurosurgeon
Radiologist
Pathologist

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What is the incidence of infective endocarditis?

3-10 episodes per 100,000 person years in general population
14.5 episodes per 100,000 person years in 70-80 year olds

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What is the difference in incidence of infective endocarditis between males and females?

Males : females

2:1

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Is the prognosis worse in males or females?

Females

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What percentage of people infected with infective endocarditis will not have an underlying structural heart disease?

Around 25%

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What are the potential epidemiologies of infective endocarditis?

Older patients with degenerative AS 
Rheumatic heart disease 
Health care associated
Invasive procedures
Intra-cardiac devices
Prosthetic valves
Mitral valve prolapse
Bicuspid aortic valve
Congenital heart disease 
IV drug abuse
Immunocompromise

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What are the potential pathophysiologies of infective endocarditis?

Adherence and invasion of non-bacterial thrombotic endocarditis
Mechanical disruption of valve endothelium

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What are the possible causes of mechanical disruption of the valve endothelium?

Turbulent blood flow
Electrodes
Catheters
Inflammation
Degenerative changes

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What percentage of people with infective endocarditis will have a physically normal endothelium?

25%

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When might bacteraemia be present in infective endocarditis?

Extra-cardiac infections
Invasive procedures e.g. oral, abdominal, genitourinary, intravascular catheters
Gingival disease

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How is infective endocarditis classified?

Acute, subacute or chronic
Early (< 1 year after surgery) or late (> 1 year after surgery)
Side of infection
Infected devices

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What is right sided infective endocarditis associated with?

IV drug abusers

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What are the presenting features of nosocomial/idiopathic infective endocarditis?

Signs and symptoms > 48 hours after hospitalisation

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What are the presenting features of non-nosocomial infective endocarditis?

Signs and symptoms < 48 hours after hospitalisation plus healthcare contact

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What factors might be associated with infective endocarditis?

Home-based nursing, IV therapy or haemodialysis < 30 days before onset
Acute care facility < 90 days before onset
Resident in nursing home or long-term care facility
IVDA

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What features might suggest infective endocarditis?

Variable presentation
High index of suspicion
Bacteraemic episode
Non-specific symptoms e.g. fever, fatigue, malaise

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What are the possible signs of infective endocarditis?

Congestive cardiac failure 
Vascular or immunological phenomena 
Immune complex deposition
Embolic phenomena 
Focal neurological signs
Peripheral embolus or abscess (30%)
Pulmonary embolus or abscess

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What are the signs of immune complex deposition?

Vasculitic rash - diffuse, non-blanching, petechial, purpuric
Roth spots - retinal haemorrhages, white/pale centre, coagulated fibrosis
Osler’s nodes - deep red spots, painful, raised, on finger plumps, palms and soles
Janeway lesions - flat, macular, echymotic, on palms and soles, non-tender
Nephritis

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What should prompt a high index of suspicion?

Fever
New murmur
Pyrexia of unknown origin when other diagnoses have been ruled out
Known IE causative organism isolated in culture 
Prosthetic material 
Previous IE 
Congenital heart disease
New conduction disorder
Immunocompromised
IVDA

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When might signs of infective endocarditis be absent?

Elderly After antibiotic treatment Immunocompromised IE involving less virulent or atypical organism

What should be done in the investigation of suspected infective endocarditis?

``` Markers of infection/inflammation FBC CRP ESR U&Es Blood culture prior to starting antibiotics Urinalysis ECG CXR Echocardiogram ```

What blood cultures should be taken in the investigation of infective endocarditis?

3 sets from different sites with > 6 hours in between In severe sepsis or septic shock then take 2 sets of bloods from different sites within 1 hour

What is the standard echocardiography protocol in infective endocarditis?

Transthoracic 1st line imaging If good quality TTE normal with low clinical suspicion then no TOE needed If TTE normal with high clinical suspicion then TOE Needed If TTE or TOE is normal but suspicion of IE remains high, repeat at 7-10 days If TTE positive then do TOE for complications, abscesses and measuring size of vegetation

When should TTE and TOE be repeated?

``` New complication New murmur Persisting fever Embolism Heart failure Abscess Atrioventricular block ```

In uncomplicated IE, when is an echo repeated?

To assess ongoing treatment for 'silent' complications and vegetation size To assess treatment success on completion - view valve morphology and cardiac function

Why might a patient with IE have negative blood cultures?

Prior antibiotic treatment Fastidious organism Intracellular bacteria

85% of all IE patients with positive blood cultures will have one of what three organisms?

Streptococci Enterococci Staphylococcus

What are the streptococci species which might be cultured in IE?

Milleri Anginosus ``` ORAL; Sanguis Mitis Salivarius Mutans Germella Morbillorum ```

What are the nutritionally variant defective streptococci which have been reclassified and might be cultured in IE?

Abiotrophia | Granulicatella

What is group D streptococcus associated with?

GI tract

What are the enterococci species that might be cultured in IE?

Faecalis Faecium Durans

What are the staphylococcal species that might be cultured in IE?

Aureus Coagulase negative Epidermidis

If a blood culture in a patient with suspected IE comes back negative due to prior antibiotic treatment, what is the most likely causative organism?

Oral streptococcus or coagulase negative staphylococcus (CNS)

What fastidious organisms might cause IE?

Nutritionally variant streptococci Fastidious gram negative bacilli - HACEK group Brucella Fungi

What percentage of IE is caused by intracellular bacteria?

What intracellular bacteria might be responsible for IE?

Coxiella burnetii Bartonella Chlamydia

How can intracellular bacteria be identified?

Serological testing Cell culture Gene amplification PCR

What are the major Duke Criteria?

Blood cultures positive for IE - typical organisms consistent with IE from 2 separate blood cultures - organisms consistent with IE from persistently positive blood cultures - single positive blood culture for Coxiella burnetii Evidence of endocardial involvement - positive echocardiogram - new valvular regurgitation/murmur

What are the minor Duke Criteria?

Predisposition - predisposing heart condition - injection drug use Fever Vascular phenomena - major arterial emboli - septic pulmonary infarcts - mycotic aneurysm - intracerebral haemorrhage - conjunctival haemorrhage - Janeway lesions Immunological phenomena - glomerulonephritis - Osler's nodes - Roth spots - rheumatoid factor Microbiological evidence - positive blood cultures that do not meet major criteria - serological evidence of active infection with organism consistent with IE

How many Duke Criteria are needed to diagnose IE?

Definite: - 2 major - 1 major and 3 minor - 5 minor Possible: - 1 major - 3 minor

What are the treatment options for IE?

Antibiotics Aminoglycosides Surgery Removal of prosthetic material

What does the choice of antibiotic for IE treatment depend on?

``` Prior received antibiotics Native or prosthetic valves Dates of any surgeries Knowledge of local epidemiology and antibiotic resistance Specific culture-negative pathogens ```

What organisms are responsible for native valve IE?

Staphylococci Streptococci HACEK species Bartonella species

What antibiotic treatment is given for IE of native valves?

4 weeks of: IV gentamicin 1mg 12 hourly and IV amoxicillin 2g 4 hourly Substitute amoxicillin for vancomycin if penicillin allergic

When is IV vancomycin used to treat IE of native valves?

If penicillin allergic Sepsis MRSA

What antibiotic treatment is given for IE of prosthetic valves?

6 weeks of: | IV gentamicin and IV vancomycin

When is Rifampicin used to treat IE of prosthetic valves?

MSSA MRSA Non-HACEK G-negative pathogens

What are the disadvantages of gentamicin?

Nephrotoxic | Ototoxic

How is gentamicin dosed?

Dosing to actual body weight or ideal body weight if obese

What investigations are repeated throughout treatment?

Daily FBC, U&Es and CRP ECG every 1-2 days Echo weekly

What patients are usually affected by fungal IE?

PVE IVDA Immunocompromised

How is fungal IE treated?

Dual anti-fungals Valve replacement Anti-fungal therapy often maintained long-term, sometimes lifelong

What are the complications/indications for surgery in IE?

``` Heart failure Fistula formation Leaflet perforation Uncontrolled infection Enlarging vegetation Abscess formation Atrioventricular heart block Embolism Embolism and vegetation > 10 mm Isolated vegetation > 15mm Prosthetic valve dysfunction/dehiscence ```

Why might there be an uncontrolled infection?

``` Inadequate antibiotic treatment Resistant organisms Locally uncontrolled infection Infected lines Embolic complications Extra-cardiac site of infection Adverse reaction to antibiotics ```

What would indicate an uncontrolled infection?

Persistent fever and positive blood cultures after 7-10 days

What is the incidence of prosthetic valve endocarditis?

1-6% of valve prosthesis Incidence of 0.3-1/2% per patient per year 10-30% of all cases of IE

What is prosthetic valve IE associated with?

Difficulties in diagnosis Difficulties with optimal therapeutic strategy Poor prognosis Removal of prosthetic material Medical therapy alone is associated with high mortality and risk of recurrence

What are the cardiac conditions at highest risk of IE?

``` Acquired valvular heart disease e.g. stenosis, regurgitation Valve replacement Structural congenital heart disease Hypertrophic cardiomyopathy Previous IE ```

What percentage of cases of IE are healthcare associated?

30%

What is the in-hospital mortality of IE?

9.6-26%

Infective Endocarditis and Rheumatic Heart Disease Flashcards

(65 cards)