Infective Endocarditis and Antibiotic Prophylaxis

• Infective endocarditis - pathogenesis:

  Bacteraemia -> erosion on endocardium -> implantation on endocardium -> vegetations
• Toxic features of infective endocarditis:

  • Pyrexia (most frequent symptom) (fever)
  • Sweats
  • Malaise, weight loss
  • Chronic anaemia, leukocytosis, high ESR (erythrocyte sedimentation rate)
  • Splenomegaly

  
• Cardiac features of infective endocarditis:

  • Arrhythmias (depending on where the damaged area is)
  • Deteriorating valve function
  • Changing murmurs
  • Heart failure
• Septic emboli (infected embolus that can travel around different parts of the circulation):

  • Limbs (iliac artery)
  • Cerebral
  • Cardiac (left anterior descending artery)
• Immune complexes:

  • Immune complexes can lodge in the kidney, leading to...
  • Glomerulonephritis -> loin pain, haematuria (blood in the urine)
• Immune complexes:

  • Immune complexes can lodge in the kidney, leading to...
  • Glomerulonephritis -> loin pain, haematuria (blood in the urine)
• Osler's nodes - sign of infective endocarditis:

  • Osler's nodes are red-purple lumps - raised and tender
  • Pain often precedes them
  • Present on fingers and/or toes
  • Last for hours to several days

  
• Splinter haemorrhages are a sign of infective endocarditis

  
• Janeway lesions are a sign of infective endocarditis. They are irregular, non-tender haemorrhagic macules located on the palms, soles, thenar and hypothenar eminences of the hands (side of thumb and side of little finger), and plantar surfaces of the toes. They typically last for days to weeks, and are usually seen with the acute form of bacterial endocarditis.

  
• Diagnosis of infective endocarditis:

  • Clinical features
  • Blood cultures (aerobic and anaerobic)
  • Imaging
• General examination of pt with infective endocarditis:

  • General look: 'Earthy' look, pallor, 'toxic' face
  • Pyrexia
  • Tachycardia, and other arrhythmias
  • Skin lesions
  • Absent pulses (embolic)
  • Eyes: sub-conjunctival haemorrhages, unilateral blindness (embolic)
• Blood cultures in are negative in 14% of cases of infective endocarditis.
• Treatment of infective endocarditis:

  • Antimicrobial treatment
  • Choice and length of antimicrobial treatment - dictated by pathogen-isolated from culture
  • Surgery
  • Management and prevention of complications
• Antibiotic prophylaxis = giving somebody a dose of antibiotics prior to a procedure that may be considered to produce a bacteraemia, leading to predisposition in some patients with cardiac problems to develop endocarditis
• Rationale for antibiotic prophylaxis:

  • Standard practice for 50 years
  • Infective endocarditis is life-threatening
  • Infective endocarditis follows bacteraemia
  • Some dental procedures cause bacteraemia
  • Causes of infective endocarditis following dental procedures
  • Infective endocarditis can be caused by oral organisms
  • These organisms are sensitive to antibiotics
• Scope of NICE guideline on antibiotic prophylaxis for infective endocarditis: To provide evidence-based recommendations to guide healthcare professionals in the appropriate care of people considered to be at increased risk of infective endocarditis who may require antimicrobial prophylaxis before an interventional procedure. Recent update.
• Antibiotic prophylaxis against infective endocarditis is not routinely recommended:

  • For people undergoing dental procedures
  • BUT Lancet paper (end 2014) called this into question
  • Recent change in NICE guidance - high and medium risk groups
• Increased risk of infective endocarditis - high risk SDCEP:

  • Previous infective endocarditis
  • Any form of prosthetic heart valve/prosthetic material used in valve repair
  • Any type of cyanotic congenital heart disease
  • Any type of congenital heart disease repaired using prosthetic material for first 6 months or for life if residual problems remain
• Risk of infective endocarditis - moderate risk - SDCEP:

  • Previous history of rheumatic fever
  • Patients with valvular heart disease
  • Patients with unrepaired congenital abnormalities of the heart valves
• SDCEP guidelines:

  • Importance of good oral hygiene
  • What signs to look out for in infective endocarditis
  • Patient management flowchart
  • Template letter for cardiologist
• Arguments 'against' prophylaxis:

  • No consistent association between having an interventional procedure and the development of infective endocarditis
  • Regular toothbrushing almost certainly presents a greater risk of infective endocarditis than a single dental procedure
  • The clinical effectiveness of antibiotic prophylaxis is not proven - but may be necessary
  • Antibiotic prophylaxis against infective endocarditis for dental procedures is not cost effective and may lead to a net loss of life
• Patient advice - healthcare professionals should offer people clear and consistent advice about prevention including:

  • Benefits and risks of antibiotic prophylaxis
  • The importance of maintaining good oral health
  • Symptoms that may indicate infective endocarditis and when to seek expert advice
  • Risks of undergoing invasive procedures such as body piercing or tattooing
  • Importance of good oral health
• Conclusions:

  • Endocarditis is a disease with which dental practitioners need to be familiar with
  • Antibiotic prophylaxis is currently not routinely indicated for bacteraemia producing dental procedures - but there are subtleties to the debate
  • Liaise if in doubt