April 24, 2007 — Prophylactic antibiotic therapy for dental procedures is unlikely to prevent many cases of infective endocarditis and should be restricted to patients who would be at highest risk for the infection, such as those with prosthetic valves or certain congenital heart defects, according to updated guidelines by the American Heart Association (AHA) published online April 19 in the Publish Ahead of Print issue of Circulation.

"We've concluded that if giving prophylactic antibiotics prior to a dental procedure works at all — and there's no evidence that it does work — we should reserve that preventive treatment only for those people who would have the worst outcomes if they get infective endocarditis," noted Chair of the new guidelines writing group Walter R. Wilson, MD, from Mayo Clinic in Rochester, Minnesota, in a statement issued by the AHA. "This changes the whole philosophy of how we have constructed these recommendations for the last 50 years."

Based on an analysis of available literature, the document concludes that "random bacteremia" resulting from routine daily activities, such as chewing food or tooth brushing, is far more likely to cause IE [infective endocarditis] than bacteremia secondary to dental procedures.

"There should be a shift in emphasis away from a focus on a dental procedure and antibiotic prophylaxis toward a greater emphasis on improved access to dental care and oral health in patients with underlying cardiac conditions associated with the highest risk of adverse outcome from infective endocarditis and those conditions that predispose to the acquisition of infective endocarditis," write the authors of the updated guidelines.

Prophylactic antibiotics, the authors state, should not be given based on a lifetime risk for infective endocarditis but are recommended for high-risk patients undergoing "procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa." Such "high-risk" patients, according to the guidelines, include those with the following:

• Prior infective endocarditis
  
  
• Prosthetic cardiac valves
  
  
• Unrepaired cyanotic congenital heart defects, including palliative shunts and conduits
  
  
• Congenital heart defects completely repaired with prosthetic material or a device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure
  
  
• Repaired congenital defects with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device
  
  
• Cardiac transplants and development of cardiac valvulopathy

Patient groups that may have received routine antibiotic prophylaxis in the past but are no longer candidates for it include those with mitral and aortic valve disease, rheumatic heart disease, or structural disorders like ventricular or atrial septal defects or hypertrophic cardiomyopathy, according to the AHA statement.

The revised guidelines were developed with the participation of and have been endorsed by the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics.

Disclosures of relevant financial relationships for the writing group and the document's reviewers are included in the guidelines.

Circulation. Published online April 19, 2007.

The complete contents of Heartwire , a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.

Clinical Context

Study Highlights

• Few published studies address the magnitude of bacteremia associated with routine dental procedures, and no published data show that a greater bacteremic load is associated with a higher risk for infective endocarditis. Moreover, it is unclear if the duration of exposure to bacteremia affects the risk for infective endocarditis. These issues make it difficult to specify dental procedures for which antibiotic prophylaxis is more beneficial.
• A crude estimate of the risk for infective endocarditis associated with dental procedures in the United States is 1 case of infective endocarditis for every 14 million dental procedures. This risk rises to 1 case per 114,000 procedures among patients with a prosthetic valve and 1 case per 95,000 procedures among patients with previous infective endocarditis.
• No prospective, randomized, placebo-controlled studies have investigated the efficacy of antibiotic prophylaxis in prevention of infective endocarditis following dental procedures. Even if antibiotics were 100% effective in preventing infective endocarditis, the relative benefit of antibiotic prophylaxis would be small.
• The new guidelines call for antibiotic prophylaxis of infective endocarditis among high-risk patients undergoing manipulation of gingival tissue or the periapical region of teeth. High-risk patients also should receive prophylaxis if undergoing a procedure that will perforate the oral mucosa. Such procedures do not include routine anesthetic injections, adjustment of orthodontic appliances, or bleeding from trauma to the oral mucosa.
• Patients eligible for antibiotic prophylaxis prior to dental or other high-risk procedures include those with a prosthetic heart valve, previous infective endocarditis, and cardiac transplantation with subsequent valvulopathy, and patients with some forms of congenital heart disease (eg, unrepaired cyanotic disease, repaired heart defect using prosthetic material within 6 months of surgery, and repaired defects with residual defects near the site of prosthetic material).
• Amoxicillin at a dose of 2 g (or 50 mg/kg in children) is recommended for most patients requiring antibiotics. This medication should be given to patients 30 to 60 minutes before the procedure. High-risk adults with penicillin allergy may receive cephalexin, 2 g; clindamycin, 600 mg; or either azithromycin or clarithromycin, 500 mg.
• No antibiotic prophylaxis is necessary before routine bronchoscopy, but high-risk patients undergoing drainage of a known respiratory tract abscess should receive antibiotics before the procedure.
• Routine antibiotic prophylaxis is not necessary before routine gastrointestinal or genitourinary procedures, including esophagogastroduodenoscopy or colonoscopy. Again, antibiotics may be considered prior to procedures designed to treat infections in the gastrointestinal or genitourinary tracts.
• High-risk patients undergoing procedures on infected skin also may receive preprocedure antibiotic prophylaxis, and this antibiotic should be active against staphylococci.

Pearls for Practice

• The current guidelines state that patients eligible for antibiotic prophylaxis prior to dental procedures include those with a prosthetic heart valve, previous infective endocarditis, cardiac transplantation with subsequent valvulopathy, unrepaired cyanotic heart disease, or recently repaired (within 6 months) congenital cyanotic disease.
• The current guidelines state that high-risk patients may be considered for treatment with prophylactic antibiotics prior to manipulation of gingival tissue or the periapical region of teeth. High-risk patients also should receive prophylaxis if undergoing a procedure that will perforate the oral mucosa. Prophylactic antibiotics are necessary before gastrointestinal, genitourinary, or skin procedures only if these locations have known infection.

CME/CE Test