Antibiotics for dental procedures not recommended for most

Antibiotics for dental procedures to prevent infective endocarditis (infection of the heart's inner lining) has been the standard of care for many years. Sufficient evidence that this is not necessary has prompted a change in the guidelines. First, a study published in BMJ (the British Medical Journal) assessed the result of stopping antibiotics for dental procedures in the UK. The authors determined to...

"...quantify the change in prescribing of antibiotic prophylaxis before invasive dental procedures for patients at risk of infective endocarditis, and any concurrent change in the incidence of infective endocarditis, following introduction of a clinical guideline from the National Institute for Health and Clinical Excellence (NICE) in March 2008 recommending the cessation of antibiotic prophylaxis in the United Kingdom."

They investigated the effects of the new guidelines that limited antibiotics for dental procedures by examining the number of prescriptions for antibiotic prophylaxis (amoxicillin or clindamycin) along with the number of cases of infective endocarditis throughout England. The results were comforting:

"After the introduction of the NICE guideline there was a highly significant 78.6% reduction in prescribing of antibiotic prophylaxis, from a mean 10 277 prescriptions per month to 2292. Evidence that the general upward trend in cases of infective endocarditis before the guideline was significantly altered after the guideline was lacking. Using a non-inferiority test, an increase in the number of cases of 9.3% or more could be excluded after the introduction of the guideline. Similarly an increase in infective endocarditis related deaths in hospital of 12.3% or more could also be excluded."

In other words, reducing the prescriptions of antibiotics for dental procedures did not significantly increase cases of infective endocarditis. Considering the major public health problem of antibiotic resistance from overuse this is welcome news. The authors conclude:

"Despite a 78.6% reduction in prescribing of antibiotic prophylaxis after the introduction of the NICE guideline, this study excluded any large increase in the incidence of cases of or deaths from infective endocarditis in the two years after the guideline."

This was followed by a study recently published in the Journal of the American College of Cardiology examining the incidence of infective endocarditis after antibiotics for dental procedures were limited in France. The authors intended to correct the paucity of...

"...data on changes in the epidemiology of IE since recent guidelines recommended restricting the indications of antibiotic prophylaxis of IE."

They conducted three 1-year population-based surveys in 3 French regions totaling 11 million inhabitants age and collected IE cases from all medical centers and analyzed incidence trends. Their data also supported the restrictions on antibiotics for dental procedures:

"IE incidence remained stable over time... Oral streptococci IE incidence did not increase either in the whole patient population or in patients with pre-existing native valve disease. The increased incidence of Staphylococcus aureus IE was not significant in the whole patient population but was significant in the subgroup of patients without previously known native valve disease."

Attention should always be paid to avoid pesky Staph infections, but it's interesting to note that oral Strep infective endocarditis did not increase even for those with pre-existing heart valve disease. The authors' conclusion supports the restriction of antibiotics for dental procedures:

"Scaling down antibiotic prophylaxis indications was not associated with an increased incidence of oral streptococcal IE. A focus on avoidance of S. aureus bacteremia in all patients, including those with no previously known valve disease, will be required to improve IE prevention."

And now we have the study, just published in the journal Circulation, on the incidence of infective endocarditis in the US after the American Heart Association introduced restrictions on antioboitics for dental procedures. The authors observe:

"The American Heart Association published updated guidelines for infective endocarditis (IE) prevention in 2007 that markedly restricted the use of antibiotic prophylaxis in certain at-risk patients undergoing dental and other invasive procedures. The incidence of IE caused by viridans group streptococci (VGS) in the United States after publication of the 2007 American Heart Association guidelines has not been reported."

They reviewed all definite or possible cases of VGS-IE cases diagnosed from January 1, 1999, through December 31, 2010 in Olmstead County, Minnesota and also examined the Nationwide Inpatient Sample hospital discharge database to determine the number of VGS-IE cases included between 1999 and 2009 to assess infective endocarditis incidences before and after the new guidelines. On the basis of their analysis the authors conclude:

"Despite marked changes in IE prevention guidelines that were published by the AHA in 2007 that restricted antibiotic prophylaxis to 4 patient groups with a high risk of complications from IE, the findings of our population-based investigation from Olmsted County suggest that the incidence of VGS IE after publication of these guidelines did not increase."

Although antibiotics for dental procedures are still recommended for some high risk patients—those with prosthetic valves, congenital heart disease, or a prior history of infective endocarditis—the updated guidelines are likely to have both individual and public health benefits.