0817 NICE guidelines on antibiotic prophylaxis to prevent infective endocarditis

In March 2008 the British National Institute for Health and Clinical Excellence (NICE) published controversial guidelines that no longer recommend antibiotic prophylaxis for dental (or respiratory) procedures, citing gastrointestinal and genitourinary procedures as the only ones that warrant prophylaxis, and only if there is suspected infection at those sites. These guidelines follow debate that has taken place over the past few years, particularly in respect of the need for prophylaxis in the case of dental procedures. In fact the evidence for risk of bacterial infection after dental procedures is weak, and was historically based on logic that said a) bacteraemia provokes endocarditis; b) bacteraemia often follows invasive procedures; and c) in animal models, antibiotics before bacterial challenge reduce the risk. Clinical reviews indicate that most cases of infective endocarditis are not related to invasive procedures and that dental treatment in the preceding 3 months was no more likely to have taken place in patients with infective endocarditis than in controls. At best, dental prophylaxis has been estimated to reduce a risk from 1/46000 to 1/150000. Other countries (France, USA) have also published guidelines in the recent past: all recognize the need to consider prophylaxis in high risk patients (in which morbidity and mortality exceed 50%). This group includes patients with previous infective endocarditis, valve replacement, prosthetic systemic or pulmonary shunt or conduit, and congenital heart disease. Staph aureus is currently regarded as being the major pathogen (rather than oral Streptococci) and one-third of cases of prosthetic valve and S aureus cases are nosocomial in origin. While some might argue that the rarity of cases related to dental procedures and oral Strep is merely the result of practice that has been entrenched over the years, opinion appears to be swinging against routine prophylaxis for at-risk patients undergoing dental procedures. There appears to be agreement that procedures involving other sites (gastrointestinal, genitourinary, ?respiratory) still require prophylaxis, with NICE specifying that this should only apply if there is infection at those sites.

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Cochrane Database Syst Rev 2004; 2: CD003813
Heart 2006; 92: 879-85
Clin Infect Dis 2006; 42: e102-7