Endocarditis Prophylaxis

ENDOCARDITIS PROPHYLAXIS

The ACC/AHA guidelines regarding prophylac-tic antibiotic regimens in patients with prosthetic heart valves and other structural heart abnormali-ties have dramatically changed in recent years, decreasing the number of indications for antibiotic administration. The risk of antibiotic administra-tion is often considered greater than the potential for developing perioperative endocarditis. At pres-ent, the ACC/AHA guidelines suggest the use of endocarditis prophylaxis in the highest risk patients undergoing dental procedures involving gingival manipulation or perforation of the oral mucosa (class IIa); see Tables 21–14 and 21–15. Such con-ditions include:

·        Patients with prosthetic cardiac valves or prosthetic heart materials

·        Patients with a past history of endocarditis

·        Patients with congenital heart diseasethat is either partially repaired or unrepaired

·        Patients with congenital heart disease with residual defects following repair

·        Patients with congenital heart disease within 6 months of a complete repair, whether catheter-based or surgical

·        Cardiac transplant patients with structurally abnormal valves

Class III recommendations indicate that pro-phylaxis is not necessary for nondental procedures, including TEE and esophagogastroduodenoscopy, except in the presence of an active infection.

Endocarditis is believed to occur in areas of cardiac endothelial damage, where in cases of bacteremia, bacteria can be deposited and multiply. Areas of increased myocardial blood flow velocity lead to damaged endothelium, providing a template for bacterial adherence and growth. Indeed, the lat-est ACC/AHA guidelines do not suggest prophylaxis for genitourinary or gastrointestinal procedures; however, the AHA does note that it is reasonable to administer antibiotics to prevent wound infection. Moreover, they note that although prophylaxis is not suggested for respiratory tract procedures, it is a reasonable strategy in high-risk patients in whom an incision has been made in the respiratory tract (eg, in tonsillectomy).

In spite of these much reduced indications, the ACC/AHA notes that many patients and phy-sicians expect the administration of endocarditisprophylaxis in patients with valvular heart dis-ease, aortic coarctation, and hypertrophic car-diomyopathy. As always, the risk of antibiotic administration must be considered in offering prophylaxis to patients outside of the ACC/AHA high-risk category. Guidelines are ever chang-ing, and although not considered to be “standard of care,” they are increasingly present in medi-cal practice; furthermore, deviation from guide-lines often requires explanation as being outside of “evidenced-based” practice. Review of ACC/ AHA guidelines, which are now available online, are recommended when high-risk patients are encountered.