Revised AHA Guidelines for Prevention of Endocarditis

Revised AHA Guidelines for Prevention of Endocarditis

Allan S. Brett, MD

Journal Watch. 2007;6(6) ©2007 Massachusetts Medical Society
Posted 07/25/2007

Major changes include a narrowed list of cardiac conditions that warrant prophylaxis, and the elimination of gastrointestinal and genitourinary indications for prophylaxis.

Summary

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).

Comment

This new guideline will substantially reduce the number of people who receive endocarditis prophylaxis. Conspicuous changes from the previous guideline include the elimination of acquired valvular dysfunction (including mitral valve prolapse) from the list of cardiac conditions warranting prophylaxis, and the elimination of gastrointestinal and genitourinary indications for prophylaxis. In my view, primary care clinicians should read the full guideline so that they can knowledgeably advise patients and dentists who might resist these changes.