Revised AHA Guidelines for Prevention of Endocarditis

The complex 1997 American Heart Association (AHA) recommendations for preventing infective endocarditis have guided practice during the past decade. However, experts have long acknowledged that the evidence to support the effectiveness of endocarditis prophylaxis is not compelling. For example, cumulative exposure to bacteremia from daily oral activities (e.g., chewing, brushing, flossing) is thousands of times greater than exposure from a few dental visits yearly. Thus, prophylaxis for dental procedures is likely to prevent only a tiny proportion of cases of endocarditis, at best.

In view of the limited evidence, the AHA has published a new guideline with the following key elements:

1. Prophylaxis is now recommended only for patients with these four conditions:

• prosthetic cardiac valve

• previous infective endocarditis

• certain types of congenital heart disease (see guideline for details)

• cardiac transplantation with valvulopathy

2. For patients with the conditions listed above, prophylaxis should be given only before:

• dental procedures that involve manipulation of gingival tissue or the periapical region of teeth, or perforation of oral mucosa (see guideline for dental procedures that do not require prophylaxis)

• incision or biopsy of respiratory tract mucosa

• procedures on infected skin or musculoskeletal structures

3. Prophylaxis is no longer recommended for gastrointestinal or genitourinary procedures. However, if urine is colonized by enterococcus, eradication before invasive urinary procedures is reasonable.

4. A single 2-g dose of amoxicillin, given 30 to 60 minutes before the procedure, remains the regimen of choice (see guideline for alternatives in cases of penicillin allergy or inability to take oral medication).