Prophylactic antibiotic treatment to prevent infective endocarditis: new guidance from the National Institute for Health and Clinical Excellence

For more than 50 years a consensus has existed that infective endocarditis (IE) is, to some extent, a preventable disease. Central to the prevention strategy has been the use of prophylactic antibiotic therapy for patients with predisposing cardiac conditions (PCCs) undergoing diagnostic and therapeutic procedures that are known to cause bacteraemia with common infecting organisms—in particular, oral streptococci and enterococci. Beyond this generic approach, expert opinion has differed over which PCCs are associated with a sufficiently high predisposition to, and which procedures expose patients to a sufficiently high risk of, developing IE to justify antibiotic cover—but the underlying principle of suppressing the bacteraemia associated with a wide range of diagnostic and interventional procedures has rarely been challenged. During recent years, however, there has been a departure from the consensus, based mainly on recognition that bacteraemia of intensity comparable to, and cumulatively far greater than, that from occasional dental procedures occurs during everyday life.

In 2006 a working group of the British Society for Antimicrobial Chemotherapy (BSAC) concluded that prophylactic treatment should be prescribed only for patients at particularly high risk either of developing endocarditis or of an adverse outcome should it occur. The following year the American Heart Association/American College of Cardiology (AHA/ACC) made similar recommendations but specified prophylaxis for only a limited list of dental procedures, and withdrew advice to cover gastrointestinal and urogenital interventions.

In response to the controversy provoked by the BSAC recommendations, the National Institute for Health and Clinical Excellence (NICE) was invited to re-examine the evidence and to develop a guideline for adoption by the National Health Service in England, Wales and Northern Ireland. Contrary to the expectations of many cardiologists, NICE proposed a still more radical departure from existing practice by concluding that prophylactic antibiotic treatment should not be utilised for any at-risk patient …