Title: Infective Endocarditis Prophylaxis'' Where are we now
1Infective Endocarditis Prophylaxis.. Where are
we now?
31st March 2009
2Infective endocarditis
- Infection of endocardium
- acute
- subacute
- chronic
- Annual incidence 1.7 6.2 per 100,000 cases
3- Occurs on
- Defective valves
- Prosthetic valves
- Congenital heart defects e.g.
- Ventricular septal defect
- Patent ductus arteriosus
- Normal valves
- 40 with IE have
- Normal heart
- Undiagnosed defect
4Turbulent blood flow traumatises endothelium
Nonbacterial thrombotic endocarditis
Bacteraemia
Further deposition of fibrin and platelets
Underwood 2004
5Causative organisms
- Streptococcus Viridans (50)
- e.g. S. mutans, S. sanguis
- Enterococcus faecalis
- Staphylococcus aureus
- More uncommonly other bacteria, fungi
6Pathology
- Vegetations along valve edges
- mass of fibrin, platelets and infectious
organisms - MV gt AV gt TV
7Clinical Features
- Malaise, fever, night sweats, weight loss,
anaemia - Valve destruction ? heart failure
- ? new/changing
murmurs - Embolic events ? abscesses in brain, liver
- Immune complex deposition ? vasculitis
-
? arthralgia -
? glomerulonephritis
8Investigations
- Normochromic normocytic anaemia
- ? WCC white cell count
- ? ESR erythrocyte sedimentation rate
- Blood cultures repeated samples
- Echocardiography
9Mortality
- Fatal if untreated
- 6 sensitive streptococci
- 30 Staph. aureus
10Management
- IV antibiotics 2/52
- (benzylpenicillin and gentamicin before results)
- Oral antibiotics 2-4/52
11Dental treatment and infective endocarditis
12MAYBE.
- Viridans group part of normal oral flora
- Antibiotic prophylaxis prevents viridans group
experimental endocarditis in animals - In some cases temporal relationship between IE
development and dental treatment.
13BUT..
- Activities of daily living, e.g. eating,
toothbrushing, flossing, produce bacteraemia - Magnitude of bacteraemia after dental procedures,
toothbrushing etc. less than that necessary to
produce IE in experimental animals - Contradictory studies on effect of antibiotic
prophylaxis on level of bacteraemia after dental
procedures
14Bacteraemia
- How often they occur?
- Magnitude?
- Duration?
15Frequency of bacteraemia
16Magnitude of bacteraemia
17Duration
- Most positive blood cultures were within 10 mins
after extraction - Only a small no. of positive blood cultures
between 30-60 mins
18Cumulative risk
- Cumulative exposure of 5370 minutes of
bacteraemia over 1 month in dentate patients from
chewing food, toothbrushing, flossing - 6-30 minutes with single extraction
- Gunteroth 1984 Am J Cardiol 54797-801
19- Toothbrushing twice daily for 1 year has a 154
000 greater risk of producing bacteraemia than a
single extraction - Roberts GJ 1999 Pediatr Cardiol 20317-325
- Dentists are innocent!
20Role of oral hygiene
- Available evidence supports importance of good OH
in preventing IE - Patients with poor OH have similar levels of
bacteraemia before extraction as after extraction
21Dental procedures
- Old guidelines cover bleeding-prone procedures
- No data to support visible bleeding during dental
treatment as a predictor of bacteraemia - No evidence base to decide what procedures might
require prophylaxis
22Effect of antibiotics on bacteraemia
- Controversial
- Recent studies suggest amoxycillin may reduce
frequency and duration of bacteraemia but does
not eliminate it - No evidence that any reduction reduces risk of IE
23Effect of chlorhexidine on bacteraemia
- Most of evidence suggests no clear benefit
24Clinical studies
- 1. 2 year case control study
- The Netherlands
- Compared IE cases with controls with matched
cardiac defect - Both groups had similar dental treatments in
preceding 180 days - 5/25 cases who developed IE within 30 days of
dental treatment did so despite adequate
prophylaxis - Van der Meer 1992 Lancet
25- 2. Multicentre case-control study
- - US study
- - Controls without IE were more likely to have
undergone dental procedure than cases of IE - Strom 1998 Ann Intern Med
26Temporal association between IE and dental
procedure
- Many reviews and case reports included cases with
dental treatment up to 6 months prior to IE - Time frame between bacteraemia and IE estimated
at - 78 within 7 days
- 85 within 14 days
27Previous prophylaxis regimes
- Expert consensus opinion
- Poor evidence base!
28Problem
- No Randomised Placebo-Controlled Double- Blind
Trial - Ethical considerations
- Large numbers required 6000 patients
29Concerns with antibiotic use
- Hypersensitivity reactions
- Anaphylactic deaths gt IE deaths?
- Fatal anaphylactic reactions in 15-25/106 who
receive dose of penicillin - Of those with prior penicillin use, 1/3 previous
allergy, 2/3 no previous allergy - AHA not aware of any case of fatal anaphylaxis in
previous 50 years
30Concerns with antibiotic use
- Resistance
- Widespread use promotes emergence of resistant
viridans group strep and enterococci - Results in decreased efficacy of treatments for
IE - Cost
31- PROPHYLAXIS??
- IF AND WHEN
32Prophylaxis when?
- A number of revised guidelines have recently been
produced - BSAC (2006)
- AHA (2007)
- NICE (2008)
- Australian (2008)
33What are guidelines?
- Clinical guidelines are recommendations on the
appropriate treatment and care of people with
specific diseases and conditions. - They are based on best available evidence
34- Stassen L, Rahman N, Rogers S, Ryan D, Healy C,
Flint S. Infective endocarditis prophylaxis and
the current AHA, BSAC, NICE and Australian
guidelines. - Journal of the Irish Dental Association 2008
54264-270
35NICE
- National Institute for Clinical Excellence
independent UK organisation that assesses
clinical and cost-effectiveness evidence and
produces guidelines on healthcare issues -
- 2008 guidelines
- No prophylaxis indicated
36AHA
- Prophylaxis for those with worst outcome if
develop IE - e.g. prosthetic valve viridans strep endocarditis
mortality 20 - native valve viridans strep endocarditis
mortality 5
37WHO?
- Prosthetic heart valve
- Previous infective endocarditis
- Cardiac transplant recipients who develop cardiac
valvulopathy - Certain congenital heart disease
38WHO?
- Certain congenital heart disease
- Unrepaired cyanotic CHD (includes palliative
shunts and conduits) - Completely repaired congenital heart defect with
prosthetic material or device within 1st 6 months
of procedure - Repaired CHD with residual defect at /adjacent to
site of a prosthetic patch / device
39WHEN?
- All dental procedures that involve manipulation
of gingival tissue or the periapical region of
teeth or perforation of the oral mucosa, - e.g.
- Extraction
- Periodontal probing, scaling, root planing and
surgery - Biopsy
- Suture removal
- Subgingival restorations
- Orthodontic band placement
40WHEN NOT?
- LA through non-infected tissues
- Dental radiographs
- Placement of removable appliances
- Placement of orthodontic brackets
- Shedding of primary teeth
- Trauma to lips/oral mucosa
41WHAT?
- BSAC guidelines
- One hour pre-op (gt10 years)
- Amoxycillin 3g po
- If penicillin allergic, clindamycin 600mg po
- Allergic to penicillin and unable to swallow
capsules, azithromycin 500mg po - Alternatively intravenous options
- Pre-operative chlorhexidine (0.2) mouthrinse
42Prophylaxis
- Appropriate prophylaxis for appropriate
treatments - Check for drug allergy
- Check for antibiotic treatment in last 4 weeks
no antibiotic prescribed more than twice in 1
month - 0.2 chlorhexidine MW 5 mins before procedure
- If patient is on Warfarin, antibiotics may
interfere with INR
43Amoxycillin
- Drug of 1st choice
- Well absorbed from GIT
- High serum concentrations
- Few side-effects
- BUT increasing resistance to penicillin
- in viridans streptococci
44Treatment planning
- When prophylaxis required maximise treatment
carried out long treatment sessions
45Treatment plan
- Non-allergic
- Week 1 amoxycillin
- Week 3 clindamycin
- Week 5 amoxycillin
- Week 7 clindamycin
46Treatment plan
- Allergic to penicillin
- Week 1 clindamycin
- Week 3 clindamycin
- Wait 4 weeks
- Week 7 clindamycin
47Prevention
- ..an underemphasis on maintenance of good oral
hygiene and access to routine dental care, which
are likely more important in reducing the
lifetime risk of IE than the administration of
antibiotic prophylaxis for a dental
procedure AHA 2007 - oral hygiene
- diet advice
- fluoride
48Benefits of new guidelines
- Simplified and greater clarity than old
guidelines - Fewer patients require antibiotic prophylaxis
- Will stimulate prospective studies on assocation
between IE and dental treatment and allow
development of further evidence-based guidelines - Reduce litigation
49- Studies necessary to establish effect of new
guidelines on incidence of IE - IE uncommon, so may be years before effect seen
50Irish Situation
- No chief dental officer
- OLCHC AHA
- DDSH in process of adopting AHA/BSAC guidelines
- CDSH initially NICE, have now changed to AHA/BSAC
51Irish attitudes to guidelines
- NICE guideline on antibiotic prophylaxis against
infective endocarditis attitudes to the
guideline and implications for dental practice in
Ireland - Nà Riordáin and McCreary BDJ (2009) 206E11
- Postal survey of dentists, cardiologists and
patients who have previously required prophylaxis.
52Dentists (290/500 responders)
- Current guidelines followed
- 78 used BSAC
- 17 used AHA
- 1 used NICE
- Intention to implement NICE
- Immediate implementation 17
- Required clearance from cardiologist/GMP 59
- Required guidance from official body 19
53Cardiologists (20/54 responders)
- 70 followed AHA5 followed NICE
- 75 happy for GDP to implement change without
consultation
54Dental patients (34/50 responders)
- 2/3 concerned re NICE guidelines
- Only 9 happy for GDP to implement them
- 79 required verbal/written confirmation from
cardiologist
55In conclusion
- Considerable changes have occurred in prophylaxis
guidelines - Resistance to change expected
- Changes will facilitate development of new
evidence based guidelines