Washington, DC and Dallas, TX - The American College of Cardiology and American Heart Association (ACC/AHA) have issued a new focused update dealing with changes in the recommendations for antibiotic prophylaxis against infective endocarditis in patients with valvular heart disease [1].

The new guidelines, published online July 28, 2008 in the Journal of the American College of Cardiology and Circulation, are a departure from the 2006 recommendations; there is no longer a class I recommendation for prophylaxis against infective endocarditis, including among higher-risk patients undergoing dental procedures. According to the new 2008 valvular-heart-disease-focused update, prophylaxis is now a class IIa recommendation for high-risk patients undergoing dental procedures. The major changes made by the ACC/AHA writing committee in the updated recommendations include:

• The writing committee concluded that only a small number of infective-endocarditis cases would be prevented with antibiotics for dental procedures, even if such prophylactic therapy were 100% effective.
• Prophylaxis for dental procedures is reasonable (class IIa recommendation) for patients with underlying cardiac conditions that have the highest risk of adverse outcomes from infective endocarditis, such as those with prosthetic cardiac valves, those with previous infective endocarditis, and those with congenital heart defects.
• For these patients, prophylaxis is reasonable for dental procedures that involve manipulation of gingival tissue or the periapical region of the teeth or a perforation of oral mucosa.
• Prophylaxis is not recommended solely on the basis of lifetime risk.
• Administration of antibiotics to prevent endocarditis is not recommended for patients undergoing a genitourinary (GU) or gastrointestinal (GI) tract procedure.

The update writing committee, chaired by Dr Rick Nishimura (Mayo Clinic, Rochester, MN), concludes that infective endocarditis is more likely to result from bacteremia associated with daily activities than from dental, GU-tract, or GI procedures. The consensus among experts now is that such antibiotic prophylaxis in susceptible individuals does not prevent endocarditis enough to justify the downside of using such large quantities of antibiotics.

"The risk of antibiotic-associated adverse effects exceeds the benefit, if any, from prophylactic antibiotic therapy," write Nishimura and colleagues. "Maintenance of optimal oral health and hygiene may reduce the incidence of bacteremia from daily activities and is more important than prophylactic antibiotics for a dental procedure to reduce the risk of infective endocarditis."

The authors note that the recommendations might contradict longstanding assumptions in practice patterns, but the update includes the analysis of new data by experts in infective endocarditis. "Because this may cause consternation among patients, clinicians should be available to discuss the rationale for these new changes with their patients, including the lack of scientific evidence to demonstrate a proven benefit for infective endocarditis prophylaxis," concludes the ACC/AHA writing committee.