Infective Endocarditis and Rheumatic Heart Disease Flashcards
Infective endocarditis (IE) is an infection of either…..
Endocardium Heart valves (prosthetic or native) Interventricular septum Chordae tendinae Intra-cardiac devices
What is the endocardium?
The inner layer of the heart
Which gender gets IE? Which has a worse prognosis?
F > M
Females worse prognosis
What % of patients with IE have no underlying structural heart disease?
25%
Who gets IE?
Older patients (generative aortic stenosis) Rheumatic heart disease Health care associated Invasive procedures Intra cardiac devices No previously known valve disease Prosthetic valves Mitral valve prolapse Bicuspid aortic valve Congenital heart disease IVDU Immunocompromised
Cardiac risk factors for IE
MVP VSD AS Rheumatic heart disease Prosthetic heart valve Cardiac surgery for native IE Prior native IE Surgery for prosthetic IE Congenital Heart disease - Cyanotic - teratology of fallot - VSD - PDA - Eisenmenger syndrome - ASD, coarctation of aorta
Non cardiac risk factors for IE
IVDU Indwelling medical devices DM AIDS Chronic skin infections/burns Genitourinary infections of manipulation including pregnancy, abortion and delivery Alcoholic cirrhosis GI lesions Solid organ transplant Homeless, body live Pneumonia, meningitis Contact with contaminated food or infected farm animals Dog / cat exposure
Common organisms causing IE with IVDU
Staph aureus CNS B haemolytic strep Fungi Aeorobic gram -ve bacilli Polymicrobial
Common organisms causing IE with indwelling medical devices
S aureus
CNS
B haemolytic strep
Strep pneumoniae
Common organisms causing IE with DM
S aureus
B haemolytic strep
Strep pneumoniae
Common organisms causing IE with AIDS
Salmonella
S pneumoniae
S aureus
Common organisms causing IE via chronic skin infections / burns
Staph areus
B haemolytic strep
Fungi
aerobic gram -ve bacilli
Common organisms causing IE via GU infections
Enterococcus GBS Listeria monocytogenes Aerobic gram negative bacilli Neisseria gonnorhoea
Common organisms causing IE via alcoholic cirrhosis
Bartonella Aeromonas Listeria S pneumonia B haemolytic strep
Common organisms causing IE via GI lesions
Strep Bovis
Enterococcus
Clostridium septicum
Common organisms causing IE via solid organ transplant
S aureus
Aspergillus fumigatus
Candida
Enterococcus
Common organisms causing IE via homelessness and lice
Bartonella
Common organisms causing IE via pneumonia or meningitis
S pnuemoniae
Common organisms causing IE via contact with containerised milk or infected farm animals
Brucella
Pasteurella
Coxiella burnetti
Erysipelothrix
Common organisms causing IE through dog/cat exposure
Bartonella
Patueruella
C septicum
Possible pathologies of IE
- Adherence and invasion of non bacterial thrombotic endocarditis (a sterile fibrin platelet vegetation)
- Mechanical disruption of valve endothelium due to a variety of factors which favours infection by most types of organisms
- Physically normal endothelium (25%) - local inflammation
What can cause mechanical disruption of valve endothelium?
Turbulent blood flow/venturi effect Electrodes Catheters Inflammation (rheumatic carditis) Degenerative changes
Steps in bacterial colonisation in IE
- Exposed stromal cells and extracellular matrix proteins trigger deposition of fibrin-platelet clots to which streptococci bind
- Fibrin adherent streptococci attract monocytes and induce them to protect tissue factor activity (TFA) and cytokines; these mediators activate coagulation cascades, attract and activate blood platelets and induce cytokine, integrin and TFA production from neighbouring endothelial cells, encouraging vegetation growth
- Colonisation of inflamed valve - In response to local inflammation, endothelial cells express integrins that bind plasma fibronectin binding proteins, resulting in endothelial internalisation of bacteria, In response to invasion, endothelial cells produce TFA and cytokines, triggering blood clotting and extension of inflammation, and promoting formation of vegetation, internalised bacteria eventually lyse endothelial cells by secreting membrane active proteins such as haemolysins
Causes of transient bacteraemia
Brushing teeth
Bowel movements
Cardiac conditions at a higher risk of IE
Acquired valvular heart disease (stenosis, regurgitation)
Valve replacement
Structural congenital heart disease (not isolated ASD, fully repaired VSD or PDA, or closure devices that are endothelialised)
Hypertrophic cardiomyopathy
Previous IE
Which side of the heart is more affected in ICDU?
Right
Presentation of IE
FEVER (very common) Fatigue / malaise Weight loss Headache MSK pain Altered mentation MURMUR (very common) Peripheral stigmata petechiae Janeway lesions Oslers nodes Splinter haemorrhages Clubbing Neurological manifestations Roths spots Splenomegaly or infarct Vascular / immunological phenomena Embolic phenomena
What vascular / immunological phenomena can be seen in IE?
Splinter haemorrhages Vasculitic rash Roths spots Oslers nodes Janeway lesions Nephritis
What is a Vasculitic rash like?
Diffuse
Non blanching
Petechial
Purpuric
What are oslers nodes?
Deep, red spots Painful Raised Finger pulps Palms/soles
What are janeway lesions?
Flat, macular Echymotic Palms / soles Non tender Pathognomonic
What are the embolic phenomena possibly seen in IE?
Focal neurological signs Peripheral embolus / abscess (30%) - renal - cerebral - splanchnic - vertebral Pulmonary embolus/abscess - right sided IE
What would give you a high index of suspicion of IE? Fever with……
New murmur Pyrexia of unknown origin Known IE causative organism Prosthetic material (PPM, ICD, prosthetic valve, baffle/conduit) Previous IE Congenital heart disease New conduction disorder Immunocompromised/IVDA
Diagnosis of IE may be absent in….
Elderly
After antibiotic treatment
Immunocompromised
IE involving less virulent/atypical organisms
Markers of infection/inflammation
FBC (neutrophilia)
CRP
ESR
What does CRP stand for?
C-reactive protein
What does ESR stand for?
Erythrocyte sedimentation rate
Investigations for IE
FBC, CRP, ESR U + Es Blood cultures (prior to Ax) Urinalysis ECG CXR ECHO
What blood cultures need to be done?
3 sets from different sites with 6 or greater hours In between
For severe sepsis / septic shock, 2 sets from different sites within 1 hour
What would a CXR show in IE?
HF
Pulmonary abscess
Types of ECHO
TTE - transthoracic
TOE - transoesophageal
What % of IE has +ve blood cultures?
85%
Causes of IE with -ve blood cultures
Prior Ax Tx
Fastidious organisms (fastidious gram -ve baciili HAEK group, nutritionally variant streptococci)
Intracellular bacteria
What are the HACEK group?
Haemophilus parainfluenzae H aphrophilus H paraphrophilus H influenzae Actinobacillus actinomycetemoitans Cardiobacterium hominis Eikenella corrodens Kingella kingae K dentrificans
What are the intracellular bacteria that can cause IE? What % of IE is this?
5%
Coxiella burnetti
Bartonella
Chlamydia
Most common streptococci causing IE
Strep viridans
What is the cause of health care associated IE?
Staph aureus
Staph epidermidis
What bacteria is most likely to cause IE with a native valve?
strep viridans (25-65%) staph aureus (20-48%)
What bacteria is most likely to cause IE if the patient is an IVDU?
staph aureus (50-60%) B haemolytic strep (10-25%)
What bacteria is most likely to cause IE if have a prosthetic valve at 2 months?
Staph epidermidis (33%) Staph aureus (22%)
What bacteria is most likely to cause IE if prosthetic valve present for 2 - 12 months?
Staph epidermidis
What bacteria is most likely to cause IE if prosthetic valve present for >12 months?
Strep viridans (31%) Staph aureus (18%)
What is the criteria used to diagnose IE?
Modified Duke Criteria
What is the modified duke criteria?
Major criteria
1. Identifying organism
2. Providing evidence of infection anywhere within the heart
Minor criteria
1. Focus on the endocarditis complex of clinical findings
What are the major criteria for the modified duke criteria?
- Blood cultures +ve for IE
- 2 separate blood cultures with typical organisms consistent with IE
- organisms consistent with IE from persistently +ve blood cultures (all 3 or majority of >4 separate cultures of blood)
- single +ve blood culture for coxiella burnetti - Evidence of endocardial involvement
- Positive ECHO
- new valvular regurgitation / murmur
What would be involved in a +ve ECHO?
Any endocardial surface, including normal myocardium
Intracardiac / device mass
Para-annular abscess
New dehiscence of prosthetic valve
What are the minor criteria for the modified duke criteria?
Predisposition - predisposing heart condition - Injection drug use Fever Vascular phenomena Immunologic phenomena Microbiological evidence
What is a common event that may happen before presenting with IE?
Recent dental appointment
What are the vascular phenomena with IE?
Major arterial emoboli Septic pulmonary infarcts Mycotic aneurysm Intracerebral haemorrhages Conjunctival haemorrhages Janeway lesions
What are the immunologic phenomena that can occur in IE?
Glomerulonephritis
Oslers nodes
Roth spots
Rheumatoid factor
What microbiological evidence would be needed for the minor criteria for IE?
+ve blood cultures (do not meet major criterion)
Serological evidence of active infection with organism consistent with IE
What things in the modified duke criteria mean definite IE?
2 major
1 major and 3 minor
5 minor
What things in the modified duke criteria mean possible IE?
1 major
3 minor
Treatment of IE
Antibiotics IV
+/- Surgery
When should Ax for IE be started?
As soon as blood cultures taken
What does the choice of Ax for IE depend on?
Have they received prior Ax? Native or prosthetic valve Local epidemiology of organisms Local antibiotic resistance Specific culture negative pathogens
What do slow growing, dormant microbes need?
Prolonged therapy - 6+ weeks
Removal of prosthetic material
Treatment of IE if native valve and for how long
Gentamicin and amoxicillin and vancomycin
4 WEEKS
Causative organisms of IE if native valve
Staph
Strep
HACEK species
Bartonella
Treatment of IE if native valve and sepsis
Gentamicin and vancomycin
Treatment of IE if prosthetic valve and for how long
Gentamicin and vancomycin and rifampicin
6 WEEKS
Causative organisms of IE with prosthetic valves
MSSA
MRSA
Non HACEK -ve pathogens
Who should rifampicin also be givenfor?
Prosthetic valves
S/Es of gentamicin
Ototoxic
Nephrotoxic
Treatment of MSSA causing IE in a native valve and for how long
Flucloxacillin 4 weeks
Treatment of MSSA causing IE if prosthetic valve and for how long
Flucloxacillin
Rifampicin
Gentamicin
6 weeks
Treatment of IE caused by strep and for how long
Benzylpenicillin 4 - 6 weeks
Treatment of IE caused by strep if penicillin allergy and for how long
Vanc 4 - 6 weeks
Gent > 2 weeks
Treatment of IE caused by enterococcus and for how long
Amoxycillinn and Gent (4 - 6 weeks) OR Gent and BenPen (4 - 6 weeks) OR if penicillin allergy Vanc and Gent (4-6 weeks)
Who are the most worrying group of patients with IE?
Those caused by fungal infection
How do patients get IE caused by fungi?
PVE
IVDU
Immunocompromised
What does PVE stand for?
Prosthetic valve endocarditis
Which fungi cause IE?
Candida
Aspergillus
Mortality of fungi causing IE
Very high (>50%)
Treatment of fungi causing IE
Dual anti fungals
Valve replacement
Complications and Indications for surgery in IE
HF Fistula formation Leaflet formation Uncontrolled infection Enlarging vegetation despite Tx Abscess formation AV heart block Embolism Prosthetic valve dysfunction / dehiscence Embolism and vegetation > 10mm Isolated vegetation >15mm
What would indicate an uncontrolled infection?
Persisting fever, + ve blood cultures > 7 - 10 days Inadequate Ax Tx Resistant organisms Infected lines Locally uncontrolled infection Embolic complications Extracardiac site of infection Adverse reaction to Ax
What is the most severe form of IE?
PVE
Treatment of PVE
Take out prosthetic material
IV Ax
Who gets prophylaxis of IE?
Those at highest risk of IE and at risk of highest adverse outcomes of IE
What is important in the prophylaxis of IE?
Good oral hygiene
Regular dental review
Is antibiotic prophylaxis recommended for IE?
NO
When should prophylaxis for IE be offered?
An Ax that covers organisms that cause IE
If the person is at risk of IE
Is receiving Antimicrobial therapy
Due to undergoing a GI or GU procedure
At a site where there is suspected infection
What % of IE are due to healthcare associated IE?
30%
Mortality of IE
9.6 - 265
Poor outcomes in IE if….
Older Prosthetic valve IE Insulin dependent DM Comorbidity IVDU Presence of complications S aureus, fungi or gram -ve bacilli ECHO findings - HF, periannular complications
Criteria for urgent valvular replacement in IE
Severe congestive cardiac failure
Overwhelming sepsis despite Ax therapy (+/- perivalvular abscess, fistulae, perforation)
Recurrent embolic episodes despite Ax therapy
Pregnancy
What valve is most commonly affected in IVDUs who have IE?
Tricuspid valve
What is an ECG change diagnostic of rheumatic fever?
Prolonged PR interval
Why does rheumatic fever occur?
Develops following an immunological reaction to recent (2 - 6 weeks ago) strep pyogenes infection
Diagnostic criteria for rheumatic fever
Evidence of recent strep infection
2 major criteria
1 major with 2 minor criteria
How can you get evidence of recent streptococcal infection?
Raised or rising streptococci Abs
Positive throat swab
Positive rapid group A streptococcal antigen test
Major criteria for diagnosis of rheumatic fever
Erythema marginatum (10% of children, rare in adults)
Syndenhams chorea (often late feature)
Polyarthritis
Carditis and valvulitis (e.g. pancarditits)
Subcutaneous nodules
Minor criteria for diagnosis of rheumatic fever
Raised ESR or CRP
Pyrexia
Arthralgia (not if arthritis major criteria)
Prolonged PR interval
