Infective Endocarditis

Question 1

what is the definition of endocarditis?

Answer 1

infection involvong the endocardal layer

Question 2

which sites of the endocardium can be infected in IE?

Answer 2

valvular structures (natuve or prosthetic)
chordae tendinae
septal defects
mural endocardium

Question 3

what is the mortality for IE?

Answer 3

15-30%

Question 4

is IE more common in males or females?

Answer 4

males

Question 5

does IE have a worse prognosis in males or females?

Answer 5

Females

Question 6

what are the health professionals involved in the care of IE patients?

Answer 6

Frontline /referring Doctors-Acute physicians/GPs
Cardiologist-Diagnostics
Microbiologist/Infectious disease team
Cardiothoracic surgeon
Radiologist
Neurologist /Neurosurgeons (for embolic events)
Reference centre(complicated Infective endocarditis)

Question 7

which groups of patient is IE seen in presently?

Answer 7

• Older patients with degenerative heart disease ( Aortic Stenosis)
• Healthcare –associated procedures
• Intra cardiac devices (ICD)
• Valve disease( Mitral valve prolapse, Bicuspid aortic valve)/Congenital heart disease
• Prosthetic valve
• IVDU
• Immunocompromised patients

Question 8

what are the risk factors for native valve IE?

Answer 8

Mitral valve disease
Rheumatic heart disease
Congenital heart disease
Degenerative  heart disease
Asymmetrical septal hypertrophy
Intravenous Drug abusers
Alcoholic cirrhosis
Diabetic mellitus
Indwelling medical devices

Question 9

which mitral valve disease increases the risk of IE?

Answer 9

mitral valve prolapse

Question 10

which congenital heart diseases increase the risk of IE?

Answer 10

Ventricular septal defect
Bicuspid aortic valve
Patent ductus arteriosus

Question 11

describe the pathophysiology of IE from endothelial disruption?

Answer 11

Normal valve endothelium is resistant to colonization and infection.

Mechanical endothelial disruption exposures extracellular matrix protein → production of tissue factors.
Deposition of fibrin and platelets→ Non-bacterial thrombotic endocarditis (NBTE).
NBTE facilitates bacterial adherence and infection.

Question 12

what can cause damage to the endothelium of heart valves causing possibly causing IE?

Answer 12

Turbulent blood flow (Venturi effect-low pressure)
Electrodes
Catheters
Inflammation (rheumatic carditis)
Degenerative valve disease

Question 13

describe the pathophysiology of IE from inflammation?

Answer 13

Endothelial inflammation without valve lesion may promote IE.

1. Inflammation of endothelial cell → expression of integrins (β1 family)
2. Integrins are transmembrane protein-binds circulating fibronectin to endothelial surface.
3. Staph aureus (other IE pathogens) carry fibronectin → binding proteins on their surface.
4. Adherent organisms trigger active internalization into valve endothelial cells.

Question 14

which invasive procedures can cause bacteraemia leading to IE?

Answer 14

• Dental procedures requiring manipulation( gingival /periapical region
• Dental procedures -perforation of oral mucosa
• GU and GI surgery
• Intravascular catheters

Question 15

which non-invasive activities can cause bacteraemia leading to IE?

Answer 15

(chewing and tooth brushing)-low grade bacteraemia of short duration but with high incidence.

Question 16

what general things can cause bacteraemia leading to IE?

Answer 16

• invasive procedures (eg. dental procedures)
• extra-cardiac infections
• non-invasive activities

Question 17

what are the main causative organisms of IE?

Answer 17

Viridans group streptococci
Staphylococcus aureus
 Enterococci 
Coagulase-negative staphylococci
 Haemophils  parainfluenzae

 Actinobacillus 
Streptococcus bovis
Fungi
Coxiella burnetii, 
Brucella species, 
Culture-negative Haemphilus species, Actinobacillus,actinomycetemcomitans, Cardiobacterium hominis, eikenella corrodens and Kingella species (HACEK)

Question 18

how can IE be classiified?

Answer 18

• Acute(days/weeks) or subacute(weeks to months)
• Nidus(localization) of infection± intra-cardaic material
• Mode of acquisition (IVDU, Healthcare or community)
• Active Infective endocarditis
• Recurrence (relapse or reinfection)

Question 19

how can IE be classified according to localization?

Answer 19

• left-sided native valve IE
• left-sided prosthetic valve IE (PVE) (early <1 year after surgey, late >1 year after surgery)
• right-sided IE
• device related IE (permanent pacemaker or cardioverter-defibrillator)

Question 20

how can IE be classified according to mode of acquisition?

Answer 20

1. Health-care associated IE: nosocomial (signs/symptoms after 48hrs in hospital) and non nosocomial (signs/ symptoms less than 48hrs in hospital and residient in nursing home, long-term care facility, hospitalised <90 days earlier, home nursing or IV therapy, haemodialysis or IV chemotherapy)
2. Community-acquired IE- signs in hospital < 48hrs after admission and not fulfillig criteria above
3. IVDA IE

Question 21

what is active IE?

Answer 21

-IE with persistant fever and positive blood cultures
-active inflammatory morphology found at surgery
-patient stillunder antibiotic therpy
histopathological evidence of active IE

Question 22

what are the classifications of recurrent IE?

Answer 22

relapse- same infection microorganism < 6months aftere initial episode
reinfection- infection with different microorgansim or same microorganims but >6monthd after initial infection

Question 23

is the presentation of IE consistent or varied?

Answer 23

varied

Question 24

which patients have an atypical presentation in IE?

Answer 24

elderly

immunocompromised

Question 25

what are the signs of acute IE?

Answer 25

- fever - embolic signs/symtpoms - decompensated (functional deterioration when healthy before) HF

Question 26

what are the signs of subacute IE?

Answer 26

- fever - non-specific constitutional symptoms or palpitation - immunologic/vascular phenomena.

Question 27

what are the common symptoms of IE?

Answer 27

``` Fever/chills Night sweats, malaise, fatigue, anorexia, weight loss Weakness Arthralgia Headache Shortness of breath ```

Question 28

what are constitutional symptoms?

Answer 28

a group of symptoms that can affect many different systems of the body.

Question 29

what are rhe clinical signs of IE?

Answer 29

``` Cardiac murmur (regurgitant murmur) with signs of heart failure Janeway lesions Osler nodes Roth spot Meningeal signs Splinter haemorrhage Cutaneous infarcts Vasculitic rash ```

Question 30

which signs of IE are from immune complex deposition?

Answer 30

Osler nodes | Roth spots

Question 31

what are Janeway lesions ?

Answer 31

Haemorrhagic ,macular, painless plaques with predilection for palms and soles.

Question 32

what are Osler nodes?

Answer 32

Small ,painful nodular lesion found on pads of fingers or toes

Question 33

what will lead you to suspect IE?

Answer 33

1. new regurgitant murmur 2. embolic events of unknown origin 3. sepsis of unknown origin (esp. if IE causative organism) 4. fever with: - intracrdiac material - previous history of IE - other predisposition to IE (immunocompromised, IVDA) - predisposition and recent intervantion with associated bacteraemia - evidence of congestive heart failure - new conduction disturbance - positive blood cultures with typical IE causative organisms or positive serology for hronic Q fever - vascular or immunological phenomena: embolic event, Roth spots, splinterhaemorrhages, Janewya lesions, Osler's nodes - foval or non-specific neurological symptoms or signs - evidence of pulmonary embolism/infiltration (right sided IE) - peripheral abscesses (renal, splenic, cerebral, vertebral) of unknown cause

Question 34

what are the investigations for IE?

Answer 34

-Blood culture- Timing. 3 sets and sites 30mins apart. +/- cultures -FBC.ESR/CRP- elevated acute inflammatory makers -U+Es- renal failure -Urinalysis- +ve for blood -ECG: PR interval prolongation ≥200ms -CXR: Pulmonary congestion or abscess. Further Imaging for subgroups – MSCT,MRI,18F-FDG -PET/CT and Leucocyte SPECT/CT –detect silent vascular phenomena/ endocardial lesions -Echocardiography ( transthoracic (TTE) ± transesophageal (TOE)

Question 35

why are FBC and CRP blood tests carried out for in IE?

Answer 35

elevated acute inflammatory markers

Question 36

why are U+Es carried for IE?

Answer 36

to look for renal failure caused by embolic events

Question 37

why is an ecg carried out in IE?

Answer 37

to look for prolongation of PR interval

Question 38

why is CXR carried out for IE?

Answer 38

look for pulmonary abscess or congestion

Question 39

what are the 2 major ESC 2015 Modified Duke's criteria for IE?

Answer 39

- Blood cultures positive for IE | - imaging positive for IE

Question 40

for blood cultures to be positive for IE what must the result be?

Answer 40

- Typical microorganisms consistent with IE from 2 separate blood cultures: - Microorganisms consistent with IE from persistently positive blood cultures: - Single positive blood culture for Coxiella burnetii or phase I IgG antibody titre >1:800

Question 41

what are are the imaging results that can be used for a positive diagnosis of IE?

Answer 41

1. Echocardiogram positive for IE:• Vegetation • Abscess, pseudoaneurysm, intracardiac stula •Valvular perforation or aneurysm • New partial dehiscence of prosthetic valve 2. . Abnormal activity around the site of prosthetic valve implantation detected by 18F-FDG PET/CT (only if the prosthesis was implanted for >3 months) or radiolabelled leukocytes SPECT/CT. 3. Definite paravalvular lesions by cardiac CT.

Question 42

what are the minor criteria in ESC 2015 Modified Duke's Criteria?

Answer 42

1. Predisposition such as predisposing heart condition, or injection drug use. 2. Fever defined as temperature >38°C. 3. Vascular phenomena (including those detected only by imaging): major arterial emboli, septic pulmonary infarcts, infectious (mycotic) aneurysm, intracranial haemorrhage, conjunctival haemorrhages, and Janeway’s lesions. 4. Immunological phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor. 5. Microbiological evidence: positive blood culture but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with IE.

Question 43

what is the combinations of major and minor criteria for definite IE diagnosis?

Answer 43

2 major 1 major + 3 minor 5 minor

Question 44

what is the combinations of major and minor criteria for possible IE diagnosis?

Answer 44

1 major + 1 minor | 3 minor

Question 45

what must be considered before treatment of IE is given?

Answer 45

- 3 sets of blood culture - whether patient has had previous antibiotic therapy - native or prosthetic valve - place of infection (community etc) and local epidemiology for antibiotic resistance and specific genuine culture negative pathogens

Question 46

what are the 3 antibiotics given in community-acquired native valve or late (>12 months post surgery) prosthetic valve endocarditis (not penicillin allergic)?

Answer 46

``` ampicillin with flucloxacillin, cloxacillin or oxacillin with gentamicin ```

Question 47

what are the 2 antibiotics given in community-acquired native valve or late (>12 months post surgery) prosthetic valve endocarditis ( penicillin allergic)?

Answer 47

vancomycin with gentamicin

Question 48

what are the 3 antibiotics given in for ealry PVE or nosocomial and non-nosocomial healthcare associated endocarditis?

Answer 48

``` vancomycin with gentamicin with rifampin (3-5 days later) ```

Question 49

what are the patient characteristic which can be used to predict a poor outcome in IE?

Answer 49

older age prosthetic valve IE dibetes mellitus comorbidity

Question 50

what are the clinical complications of IE which can be used to predict a poor outcome?

Answer 50

``` heart failure renal failure more than a moderate area of ischaemia stroke brain haemorrhage septic shock ```

Question 51

which microorgansims cause a poor outcome in IE?

Answer 51

staph aureus fungi non-HACEK gram negative bacilli

Question 52

what are the echo findings which can predict a porr outcome of IE?

Answer 52

``` periannular complications severe left-sided valve regurgitation low left ventricular ejection fraction pulmonary hypertension large vegetations severe prosthetic valve dysfunction premature mitral valve closure and other signs of elevated diastolic pressures ```

Question 53

what are the complications and indications for srugery in IE?

Answer 53

heart failure- (valvular regurg.) uncontrolled infection (perivavular abscess) prevention of systemic embolisation (migration of cardiac vegetation to brain/spleen from left IE

Question 54

which patients are given prophylaxis for IE?

Answer 54

1. patients with any prosthetic valve 2. patients with a previous episode of IE 3. patients with CHD: a) cyanotic CHD b) any type of CHD repaired with prosthetic material up to 6 months after procedure. (lifelong if residula vegetations of shunt)

Question 55

what are the preventative measures for IE?

Answer 55

- Strict dental and cutaneous hygiene. Dental follow-up twice a year. - Disinfection of wounds. - Eradication or decrease of chronic bacterial carriage :skin, urine etc - Curative antibiotics for any focus of infection. - No self-medication with antibiotics. - Strict infection control measures for any at-risk procedures. - Discourage piercing and tattooing. - Limit the use of infusion catheters and invasive procedures when possible.