Prevention of infective endocarditis: a review of the American Heart Association guidelines

Abstract

Ever since the last American Heart Association (AHA) publication on prevention of infective endocarditis (IE) many medical societies and physicians have questioned the efficacy of prophylaxis in patients that undergo a dental, genitourinary (GU) or gastrointestinal (GI) procedures. In 1997 AHA recognize that most cases of IE were not related to invasive procedures but as a result of arbitrarily occurring bacteremia from routine daily activities as well as recognition of the possibility of IE prophylaxis failure. This assumptions as well as review of numerous published studies over the past two decades caused that AHA to revise the guidelines of 1997. Based on published series this new guidelines identify the following underlying cardiac conditions with an increase risk of IE and are the ones in which prophylaxis is recommended. They include (1) prosthetic cardiac valve or prosthetic material used for cardiac valve repair, (2) previous IE, (3) Congenital Heart Disease (CHD) including unrepaired cyanotic as well as palliative shunts and conduits, completely repaired congenital heart defect with prosthetic material or device during the first six months after the procedure, repaired CHD with residual defects and (4) cardiac transplantation recipients who develop cardiac valvulopathy. All dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa will require IE prophylaxis. Patients that undergo respiratory tract procedure that involves incision or biopsy of the respiratory mucosa will also required IE prophylaxis. In contrast to previous AHA guidelines, antibiotic prophylaxis to prevent IE is not recommended for GU or GI procedures. First line therapy recommended includes amoxicillin or ampicillin and if allergic to penicillin, clindamycin 600 mg or azithromycin 500 mg. Antibiotics should be administered in a single dose before the procedure, but the dosage may be administered up to two hours after procedure. This new AHA recommendation are more clear for healthcare providers regarding to which patient should undergo prophylaxis in comparison with previous ones and are expected to reduce antibiotic resistance that increased during the past years as a result of previous antibiotic prophylaxis for IE.