Texte de consensus: Prophylaxie de l'endocardite infectieuse

Estimated risk of endocarditis in adults with predisposing cardiac conditions undergoing dental procedures with or without antibiotic prophylaxis

BACKGROUND

Although antibiotic prophylaxis for infective endocarditis (IE) has been recommended for persons with predisposing cardiac conditions (PCCs) for many years, its efficacy, which has not been demonstrated, has been recently challenged. To assess its usefulness, we estimated the risk of developing IE after undergoing a dental procedure for which subjects would be eligible for prophylaxis, both in subjects having (protected procedure) or not having (unprotected procedure) received antibiotic prophylaxis.

METHODS

The number of French persons with PCCs, the annual number of dental procedures in which subjects would be eligible for antibiotic prophylaxis, and the number of procedures that were unprotected were estimated on the basis of a survey performed on a sample of 2805 subjects aged 25-84 years. The annual number of IE cases possibly due to an unprotected procedure was estimated on the basis of a 1-year epidemiological study of IE conducted in an area inhabited by 16 million people.

RESULTS

After standardization, extrapolation of results to the age-equivalent general population (39 millions subjects) indicated the following: first, 3.3% (95% confidence interval [CI], 2.6%-4%) of the subjects had PCC, 2.7 million (95% CI, 2.3-3.2 million) of whom had undergone at least 1 at-risk dental procedures within the survey year, and the procedures were unprotected in 62% of cases; second, 37 (95% CI, 18-68; 2.7%) of the 1370 annual IE cases in France were possibly related to unprotected procedures. Thus, the risks of developing IE were estimated to be 1 in 46,000 for unprotected procedures (1 in 10,700 and 1 in 54,300 for subjects with prosthetic and native valve PCC, respectively) and 1 in 150,000 for protected procedures.

CONCLUSIONS

A huge number of prophylaxis doses would be necessary to prevent a very low number of IE cases.

A critical appraisal of the quality of the management of infective endocarditis

OBJECTIVES

The purpose of this study was to assess the quality of the management of infective endocarditis.

BACKGROUND

Although many guidelines on the management of infective endocarditis exist, the quality of this management has not been evaluated.

METHODS

We collected data on all patients (116) hospitalized with infective endocarditis over 1 year in all hospitals in the Rhône-Alpes region (France).

RESULTS

Prophylactic antibiotics were not given before infective endocarditis to 8/11 cardiac patients at risk and who underwent an at risk procedure. Among the 55 cardiac patients at risk and with fever and who consulted a physician, blood cultures were not performed before antibiotic therapy was initiated for 32 patients. In-hospital antibiotic therapy was incorrect for 23 patients. The portal of entry was not treated for 16/61 patients with an accessible portal of entry. Among the 19 patients who had severe heart failure or fever persisting more than 2 weeks in spite of antibiotic therapy and who could have undergone early surgery, surgery was delayed for five, and not performed for three. Overall, the average score was 15/20.

CONCLUSIONS

More information on the management of infective endocarditis should be widely disseminated to the physicians' and the dentists' communities and to the patients at risk.

-Curative and preventive antibiotic therapy in infective endocarditis-

Durack's criteria, including echocardiographic manifestations, are the current standard for the diagnosis of infective endocarditis (IE). The most common microorganisms known to cause IE are streptococci and staphylococci, and therapeutic principles are based on an association of parenteral antibiotics, as far as possible bactericidal and prolonged. Treatment also includes the search for the source of infection and its eradication. IE with negative blood cultures requires special techniques to obtain the causal microorganisms. In about half of the cases, a nosocomial bacteriaemia results in IE in patients with a prosthetic valve. Surgery is mandatory in IE with complications and/or caused by particular microorganisms; surgery is essential in most patients with a prosthetic valve. Although the presence of specific links between some procedures and the occurrence of IE has not been clearly proven, a prevention policy is nevertheless justified, considering the morbidity and mortality. Prophylaxis is indicated in patients with the cardiac conditions at risk for IE. IE prophylaxis prevails over prophylactic antibiotics usually administered for surgery.

[Infectious endocarditis, risk factors, prevention. Research group for infectious endocarditis and jury of the consensus conference]

Infective endocarditis, resulting from deposition of circulating microorganisms during a period of bacteremia on damaged endothelial heart valves, remains a serious disease. Its overall incidence did not decline in recent years, 24 cases/year/million inhabitants, in France. This can be explained by a modification of the type of underlying cardiac conditions with regression of rheumatic fever and increase of degenerative heart diseases, prosthetic valves and mitral valve prolapse. The risk of bacterial seeding on a damaged valve remains difficult to evaluate, the highest risk being for patients with prosthetic valve, previous infective endocarditis and cyanotic congenital heart disease. A case-control study, done in 1991, confirmed that procedures are risk factors for infective endocarditis and that the multiplicity of procedures increases the risk. A French consensus conference on the prophylaxis of infective endocarditis has updated the recommendations for antibiotic prophylaxis. Two groups of cardiac patients were identified, based on the incidence and the severity of endocarditis occurring in patients with these conditions, 1) patients considered at risk which require specific prophylaxis, and 2) patients considered non at risk which do not require antibiotic prophylaxis. Procedures which require antibiotic prophylaxis are dental procedures and specific gastrointestinal and urologic procedures. As complex protocols are associated with poor compliance by practitioners and patients, the jury has aimed for simplicity and feasibility.