Controversy Over Antibiotic Prophylaxis for Infective Endocarditis

John G. Bartlett, MD


April 06, 2009

This article reviews the recent controversy over antibiotic prophylaxis guidelines to prevent infective endocarditis in the United Kingdom.

Antibiotic Prophylaxis Against Infective Endocarditis: New Guidelines, New Controversy?

Bogle RG, Bajpai A
Br J Cardiol. 2008;15:279-280

Article Summary

In 2004, the Royal College of Physicians/British Cardiac Society published guidelines on the use of antibiotic prophylaxis for patients undergoing dental procedures. New guidelines were published in 2006 by the British Society for Antimicrobial Chemotherapy.[1,2] These guidelines were welcomed by most dentists but deplored by cardiologists. Then came NICE, the National Institute for Health and Clinical Excellence, which was charged with clarifying the issue. NICE is a national organization appointed by statute, and recommendations from this group have substantial clout as national standards. The NICE review set out to answer the following questions: Which cardiac conditions are associated with the greatest risk for infective endocarditis (IE)? Are dental procedures associated with acute IE? Does antibiotic prophylaxis prevent IE?

The resulting NICE guidelines concluded that patients with heart disease were at increased risk for IE, but the NICE review did not produce convincing evidence that antibiotic prophylaxis was cost-effective. Their calculations, which were based on amoxicillin prophylaxis, indicated that the cost of preventing a single case would be about £12 million. In the absence of good evidence for clinical effectiveness they recommended against antibiotic prophylaxis regardless of the cardiac lesion.

This editorial review of the NICE guidelines likened the contributing data to the Dead Sea scrolls, calling them "fragmented, imperfect, subject to various interpretations and mainly missing." The editorial concluded that supporting data were based primarily on expert opinion, which accounts for the difference between the British guidelines and those by the American Heart Association.

The review authors noted that comments from the dental community favored the new recommendations, but cautioned that this was a "very significant shift in current clinical practice," and some believed that the step was too great. A survey of cardiologists prior to the release of the NICE guidelines indicated that 94% thought there was a moderate risk for endocarditis and 96% believed that it was unsafe not to give antibiotic prophylaxis to such patients.

The editorialists' conclusion is that the NICE guidelines are not enforceable by law, but they may direct cardiologists who do not believe in them to comply with them anyway because any "potential legal action could be robustly defended."