Endocarditis Prophylaxis

I. What every physician needs to know.

Infective endocarditis (IE) is an uncommon but life-threatening disease. It occurs as a complication of bacteremia by organisms that can adhere to endocardial tissue including chambers, valves, and adjacent structures. Transient bacteremia from some of these organisms, such as viridans group streptococci, can occur during invasive medical or dental procedures. Certain structural cardiac abnormalities place patients at greater risk for developing infective endocarditis. Moreover, the consequences of IE are also more severe in patients with some types of cardiac disease.

Endocarditis prophylaxis seeks to prevent IE by administering antibiotics to high-risk patients when they undergo procedures that can induce bacteremia. The 2007 guideline from the American Heart Association (AHA), has been significantly simplified from previous updates and forms the basis for the recommendations in this chapter. When considering IE prophylaxis, providers should be aware that:

  • There is very little evidence that prophylaxis against IE is effective and recommendations are based on limited data and expert opinion.

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  • Even with appropriate IE prophylaxis, only an extremely small number of cases might actually be prevented.

  • Most cases of IE are not from invasive procedures, but rather from bacteremia related to routine daily activities such as tooth brushing, flossing, and chewing.

    Most of the cases of IE have not had a dental procedure within 2 weeks before onset of symptoms of IE.

  • The guideline substantially reduced the number of patients eligible for IE prophylaxis.

    The guideline reduced the list of cardiac conditions for IE prophylaxis to encompass only those considered to be high-risk cardiac conditions.

    Patients with mitral valve prolapse no longer require antibiotic prophylaxis.

    To be eligible for IE prophylaxis, a patient must meet criteria for both a high-risk cardiac condition and a specific procedure.

    The guideline no longer recommends antibiotics prior to gastrointestinal (GI) or genitourinary (GU) procedures to prevent IE, unless there is an active GI or GU infection in which case prophylaxis should be directed against enterococci.

II. Diagnostic Confirmation: Are you sure your patient has Endocarditis?


A. History Part I: Pattern Recognition:


B. History Part 2: Prevalence:


C. History Part 3: Competing diagnoses that can mimic Endocarditis.


D. Physical Examination Findings.


E. What diagnostic tests should be performed?


1. What laboratory studies (if any) should be ordered to help establish the diagnosis? How should the results be interpreted?


2. What imaging studies (if any) should be ordered to help establish the diagnosis? How should the results be interpreted?


F. Over-utilized or “wasted” diagnostic tests associated with this diagnosis.

It is rarely necessary to perform echocardiography just to determine whether a patient has a cardiac abnormality that would warrant IE prophylaxis.

III. Default Management.

Antibiotics to prevent IE should only be provided to patients with cardiac conditions associated with the highest risk of adverse outcomes from IE (See Table I) when they undergo a procedure that causes important bacteremia (See Table II). Neither the cardiac condition or the type of procedure alone is sufficient to warrant IE prophylaxis. Table III describes the recommended prophylactic antibiotic regimen.

Table I.
Previous infective endocarditis
Prosthetic heart valves or valve repair using prosthetic material
Certain congenital heart disease (CHD):

Unrepaired cyanotic CHD, including palliative shunts and conduits

Completely repaired CHD, using prosthetic material or device, during the first 6 months after the procedure

Repaired CHD with residual defect at or near a site where prosthetic material or device was used

Cardiac transplantation recipients who develop valve disease
Table II.
Dental: All dental procedures that manipulate gingival tissue or periapical region of teeth, or that perforate oral mucosa
Respiratory Tract: Procedures that involve incision or biopsy of respiratory mucosa
Skin and Soft Tissue: Procedures performed on infected skin or soft tissue
Table III.
Preferred Oral Antibiotic:

Amoxicillin 2 g PO (50 mg/kg in children)

Penicillin Allergy:

Cephalexin 2 g PO (50 mg/kg in children)

Clindamycin 600 mg PO (20 mg/kg in children)

Azithromycin 500 mg PO (15 mg/kg in children)

Clarithromycin 500 mg PO (15 mg/kg in children)

Unable to Take Oral Medication:

Ampicillin 2 g IV or IM (50 mg/kg in children)

Cefazolin 1 g IV or IM (50 mg/kg in children)

Ceftriaxone 1 g IV or IM (50 mg /kg in children)

Clindamycin 600 mg IV or IM (20 mg/kg in children)


All antibiotics are given as single dose 30-60 minutes prior to procedure

For patients undergoing procedures on infected skin or soft tissue, an agent active against Staphylococcus aureus should be considered, such as anti-staphylococcal beta-lactam, clindamycin, or vancomycin

Patients on chronic antibiotic therapy should receive IE prophylaxis with an antibiotic from a different class than the pre-existing agent

Antibiotics should be administered in a single dose 60 minutes prior to the procedure. If vancomycin is administered, it should be given 120 minutes prior to the procedure. Of note, this is a change based on 2013 antimicrobial prophylaxis guidelines jointly formulated by IDSA, SHEA, SIS, and AHSP. If the antibiotic is unintentionally not given before the procedure, it may be given within a 2-hour window postprocedure.

Special antibiotic situations

The current (2007) AHA guideline no longer recommends antibiotics prior to GI or GU procedures to prevent IE, unless there is an active GI or GU infection, in which case prophylaxis should be directed against enterococci.

If the possibility of established IE exists before the procedure, draw blood cultures first, then administer antibiotics. Otherwise there may be a delay and treatment of a concomitant case of IE.

For cardiac surgery patients, prophylaxis should be given immediately before the operative procedure, repeated during the prolonged procedure to maintain serum concentrations, and continued for 48 hours postoperatively. Therapy should be directed against Staphylococcus. A first-generation cephalosporin may be used, but consider patterns of the institution.

If the patient is already on an antibiotic that is recommended for IE prophylaxis, select an antibiotic from a different class to avoid encountering resistance.

A. Immediate management.


B. Physical Examination Tips to Guide Management.


C. Laboratory Tests to Monitor Response To, and Adjustments in, Management.


D. Long-term management.


E. Common Pitfalls and Side-Effects of Management.

Common pitfalls

There are conditions and scenarios where antibiotic prophylaxis for IE is not indicated. They include the following:

  • Dental procedures and scenarios

    Anesthetic injections through non infected tissue

    Dental X-rays

    Placement of removable dental appliances

    Adjustment of orthodontic appliances

    Placement of orthodontic bracket

    Shedding of deciduous teeth

    Bleeding from mouth trauma

  • GI and GU procedures

    Esophagogastroduodenoscopy (EGD)


    Endoscopic retrograde cholangiopancreatography (ERCP)


  • Cardiac procedures and scenarios

    Coronary artery bypass graft (CABG)

    Coronary stent placement

    Cardiac transplantation

    Isolated atrial septal defect

    Surgical repair of atrial septal defect, ventricular septal defect, or patent ductus arteriosus (without residual lesions after six months)

    Mitral valve prolapse

    Previous Kawasaki disease

    Previous rheumatic heart disease

    Cardiac pacemakers

    Acquired valvular dysfunction


Side effects of management

Antibiotics used in IE prophylaxis can cause adverse reactions. Consequences may include rash, diarrhea, and GI disturbances, but are usually self-limited. Fatal anaphylaxis is possible, but no reports of such an occurrence from the administration of penicillin based on AHA guidelines has been reported. There has been only one case report of Clostridium difficile colitis after a dose of clindamycin.

Antibiotic use is also associated with facilitating proliferation of resistant organisms. Multidrug resistant viridans group streptococci and enterococci have increased dramatically over the past 20 years. This has reduced the efficacy and number of antibiotics available for the treatment of IE.

IV. Management with Co-Morbidities.


A. Renal Insufficiency.


B. Liver Insufficiency.


C. Systolic and Diastolic Heart Failure.


D. Coronary Artery Disease or Peripheral Vascular Disease.


E. Diabetes or other Endocrine issues.


F. Malignancy.


G. Immunosuppression (HIV, chronic steroids, etc).


H. Primary Lung Disease (COPD, Asthma, ILD).


I. Gastrointestinal or Nutrition Issues.


J. Hematologic or Coagulation Issues.


K. Dementia or Psychiatric Illness/Treatment.


V. Transitions of Care.

A. Sign-out considerations While Hospitalized.


B. Anticipated Length of Stay.


C. When is the Patient Ready for Discharge.


D. Arranging for Clinic Follow-up.


1. When should clinic follow up be arranged and with whom.


2. What tests should be conducted prior to discharge to enable best clinic first visit.


3. What tests should be ordered as an outpatient prior to, or on the day of, the clinic visit.


E. Placement Considerations.


F. Prognosis and Patient Counseling.

The recommendations on preventing IE have been evolving for 50 years. Patients may have particular expectations regarding antibiotic use prior to procedures and may express concern over the changes to those routines. They can be re-educated and counseled using the points in Table IV. In particular, they should be counseled that maintenance of good oral hygiene may reduce the risk of bacteremia and IE, and this may be more important than the antibiotics for a dental procedure.

Table IV.
IE is much more likely to result from exposure to random bacteremia associated with daily activities than from bacteremia caused by a dental, GI tract, or GU tract procedures.
Prophylaxis may prevent an exceedingly small number of cases of IE, if any, from prophylactic antibiotic therapy.
The risk of antibiotic-associated adverse events exceeds the benefits, if any, from prophylactic antibiotic therapy.
Maintenance of optimal oral health and hygiene may reduce the incidence of bacteremia from daily activities and is more important than prophylactic antibiotics for a dental procedure to reduce the risk of IE.

VI. Patient Safety and Quality Measures.

A. Core Indicator Standards and Documentation.


B. Appropriate Prophylaxis and Other Measures to Prevent Readmission.


VII. What's the evidence?

Wilson, W, Taubert, KA, Gewitz, M, Lockhart, PB. “Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group”. Circulation. vol. 116. 2007 Oct 9. pp. 1736-54.

Nishimura, RA, Otto, CM, Bonow, RO, Carabello, BA. “2014 AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines”. Circulation. vol. 129. 2014 Jun 10. pp. 2440-92.

Bratzler, DW, Dellinger, EP, Olsen, KM, Perl, TM. “Clinical practice guidelines for antimicrobial prophylaxis in surgery”. Am J Health Syst Pharm. vol. 70. 2013 Feb 1. pp. 195-283.

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