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Infective Endocarditis Prophylaxis'' Where are we now

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Title: Infective Endocarditis Prophylaxis'' Where are we now


1
Infective Endocarditis Prophylaxis.. Where are
we now?
  • Dr. Claire Healy

31st March 2009
2
Infective 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

4
Turbulent blood flow traumatises endothelium
Nonbacterial thrombotic endocarditis
Bacteraemia
Further deposition of fibrin and platelets
Underwood 2004
5
Causative organisms
  • Streptococcus Viridans (50)
  • e.g. S. mutans, S. sanguis
  • Enterococcus faecalis
  • Staphylococcus aureus
  • More uncommonly other bacteria, fungi

6
Pathology
  • Vegetations along valve edges
  • mass of fibrin, platelets and infectious
    organisms
  • MV gt AV gt TV

7
Clinical 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

8
Investigations
  • Normochromic normocytic anaemia
  • ? WCC white cell count
  • ? ESR erythrocyte sedimentation rate
  • Blood cultures repeated samples
  • Echocardiography

9
Mortality
  • Fatal if untreated
  • 6 sensitive streptococci
  • 30 Staph. aureus

10
Management
  • IV antibiotics 2/52
  • (benzylpenicillin and gentamicin before results)
  • Oral antibiotics 2-4/52

11
Dental treatment and infective endocarditis
  • Is there a link?

12
MAYBE.
  • 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.

13
BUT..
  • 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

14
Bacteraemia
  • How often they occur?
  • Magnitude?
  • Duration?

15
Frequency of bacteraemia
16
Magnitude of bacteraemia
17
Duration
  • Most positive blood cultures were within 10 mins
    after extraction
  • Only a small no. of positive blood cultures
    between 30-60 mins

18
Cumulative 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!

20
Role 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

21
Dental 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

22
Effect 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

23
Effect of chlorhexidine on bacteraemia
  • Most of evidence suggests no clear benefit

24
Clinical 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

26
Temporal 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

27
Previous prophylaxis regimes
  • Expert consensus opinion
  • Poor evidence base!

28
Problem
  • No Randomised Placebo-Controlled Double- Blind
    Trial
  • Ethical considerations
  • Large numbers required 6000 patients

29
Concerns 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

30
Concerns 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

32
Prophylaxis when?
  • A number of revised guidelines have recently been
    produced
  • BSAC (2006)
  • AHA (2007)
  • NICE (2008)
  • Australian (2008)

33
What 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

35
NICE
  • 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

36
AHA
  • 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

37
WHO?
  • Prosthetic heart valve
  • Previous infective endocarditis
  • Cardiac transplant recipients who develop cardiac
    valvulopathy
  • Certain congenital heart disease

38
WHO?
  • 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

39
WHEN?
  • 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

40
WHEN 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

41
WHAT?
  • 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

42
Prophylaxis
  • 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

43
Amoxycillin
  • Drug of 1st choice
  • Well absorbed from GIT
  • High serum concentrations
  • Few side-effects
  • BUT increasing resistance to penicillin
  • in viridans streptococci

44
Treatment planning
  • When prophylaxis required maximise treatment
    carried out long treatment sessions

45
Treatment plan
  • Non-allergic
  • Week 1 amoxycillin
  • Week 3 clindamycin
  • Week 5 amoxycillin
  • Week 7 clindamycin

46
Treatment plan
  • Allergic to penicillin
  • Week 1 clindamycin
  • Week 3 clindamycin
  • Wait 4 weeks
  • Week 7 clindamycin

47
Prevention
  • ..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

48
Benefits 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

50
Irish Situation
  • No chief dental officer
  • OLCHC AHA
  • DDSH in process of adopting AHA/BSAC guidelines
  • CDSH initially NICE, have now changed to AHA/BSAC

51
Irish attitudes to guidelines
  • NICE guideline on antibiotic prophylaxis against
    infective endocarditis attitudes to the
    guideline and implications for dental practice in
    Ireland
  • Ní Riordáin and McCreary BDJ (2009) 206E11
  • Postal survey of dentists, cardiologists and
    patients who have previously required prophylaxis.

52
Dentists (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

53
Cardiologists (20/54 responders)
  • 70 followed AHA5 followed NICE
  • 75 happy for GDP to implement change without
    consultation

54
Dental 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

55
In conclusion
  • Considerable changes have occurred in prophylaxis
    guidelines
  • Resistance to change expected
  • Changes will facilitate development of new
    evidence based guidelines
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