Endocarditis: Preventive Measures

Endocarditis is a bacterial inflammation of the endocardium (inner lining of the heart) that is subacute or highly acute and is associated with a high mortality rate. Since bacteria from the oral cavity can enter the vascular system during dental procedures and cause transient bacteremia (presence of bacteria in the blood), there is a risk that these bacteria may cause endocarditis in patients with certain risk factors. Bacterial colonization of the endocardium should be prevented by so-called endocarditis prophylaxis in the form of prophylactic antibiotic administration. In patients at risk, turbulent flow is present at constriction sites or endocardial lesions in the heart. There, thrombi (blood clots) can become lodged on the endocardium, which in turn become colonized by the bacteria that cause endocarditis. According to a cohort study of approximately 139,000 subjects, the risk of developing infective endocarditis was increased by an average of 25% in the three months following an invasive dental procedure (compared with periods without such procedures). With antibiotic endocarditis prophylaxis, the incidence was 17% lower on average; without prophylaxis, it was 58% higher. A paradigm shift has taken place in endocarditis prophylaxis in recent years: the various professional societies have severely restricted their recommendations for antibiotic administration, which was previously routinely performed on a broad basis in patients with heart defects (including cardiac malformation, cardiac vitium) or valvular heart disease. The background to the change in approach is the following facts:

  • It must be assumed that everyday hygiene measures such as dental hygiene and even mastication itself regularly lead to bacteremia. Should a patient be susceptible to the development of endocarditis due to his general condition, only a very small percentage of endocarditis could be prevented with the passive administration of antibiotics in connection with dental treatment anyway.
  • The concept of endocarditis prophylaxis lacks appropriate standardized studies in humans that prove the effectiveness and efficiency of prophylaxis; rather, the approach is based on case reports, animal studies and partly inconsistent expert opinions.

In another point, the experts also agree: good oral hygiene and good dental care with fillings, if necessary dentures and freedom from inflammation of the periodontium are of great importance for the patients at risk as prophylaxis of infective endocarditis. Although dental care itself can also cause bacteremia, it is precisely for this reason that it is important to reduce the number of germs residing in the oral cavity to a minimum by exhausting all possibilities through excellent oral hygiene.

Indications (areas of application)

Prophylaxis is now recommended by all professional societies only for high-risk patients in whom endocarditis would most likely take a severe or lethal (fatal) course in the event of disease:

  • Patients with mechanical or biological heart valve replacement.
  • Patients with reconstructed valves made of alloplastic material (these materials are similar to bone tissue, but are manufactured synthetically) in the first six months after surgery; the material is completely covered with and integrated into endocardium after this time period
  • Patients with survived endocarditis, as they have a higher complication rate when new disease is present
  • Patients with congenital cyanotic heart defects (= heart defects with right-to-left shunt; these are characterized by cyanosis – bluish discoloration of the skin or mucous membranes – caused by bypassing the pulmonary circulation. ) who have not had surgery at all or who have had palliative care with a systemic-pulmonary shunt (connection between the systemic and pulmonary circulation)
  • Patients with operated cardiac defects with implanted conduits (with and without valves) or residual defects, resulting in turbulent flow, i.e., turbulent blood flow in the area of the prosthetic material
  • Any cardiac defect treated surgically or interventrally with prosthetic material during the first six postoperative months
  • Heart transplanted patients with cardiac valvulopathy (heart valve damage).

For above patients, the recommendation for antibiotic coverage is available for the following dental procedures:

  • All procedures on the gingiva (gums), such as scaling and periodontal surgery.
  • Intraligamentary anesthesia (ILA), in which anesthesia is provided by injecting a local anesthetic (local anesthetic) under high pressure of 90-120 newtons directly into the – bacterially colonized – desmodontal crevice (gap between tooth and bone)
  • All interventions in the area of the apices (the root tips), so for example the root tip resection.
  • All procedures that are associated with perforations of the oral mucosa (oral mucosa), such as trial excisions (removal of biopsies) or already the application of bands for fixed orthodontic appliances; all procedures of oral surgery.

Expressly excluded from endocarditis prophylaxis are:

  • Local anesthesia in tissue free of inflammation.
  • Dental X-ray
  • Suture removals
  • Insertion of removable orthodontic appliances
  • Adjustment of prosthetic anchorage elements
  • Lip trauma
  • Trauma of the oral mucosa (oral mucosa)
  • Physiological (natural) loss of deciduous teeth.

Contraindications

Cephalosporins should generally not be given if the patient has already suffered an anaphylactic event, angioedema (synonym: Quincke’s edema; this is a rapidly developing, painless, itchy edema (swelling) of the skin, mucosa, and adjacent tissues), or urticaria (hives) after penicillin or ampicillin administration. In addition, it follows from what has been said previously that prophylactic administration of antibiotics is not indicated outside the narrowly defined regimen of use.

The procedure

Antibiotic administration during dental procedures primarily targets viridans-group streptococci. The single dose is administered 30-60 min before the procedure. If this has not been done, subsequent administration up to 2 h postoperatively (after the procedure) is considered useful.

Drug group Active ingredient Single dose adult Single dose children
Aminopenicillins Amoxicillin 2 g p.o. 50 mg/kg bw p.o.
1st generation oral cephalosporins. Cefalexin 2 g p.o. 50 mg/kg bw p.o.
Aminopenicillins Ampicillin 2 g i.v. 50 mg/kg bw i.v.
Group 1 parenteral cephalosporins. Cefazolin 1 g i.v. 50 mg/kg bw i.v.
Group 3a parenteral cephalosporins. Ceftriaxone 1 g i.v. 50 mg/kg bw i.v.
Lincosamide Clindamycin 600 mg p.o./i.v. 20 mg/kg bw p.o./i.v.In penicillin/ampicillin allergy.

In oral abscesses (encapsulated collection of pus), involvement of Staphylococcus aureus must also be expected. Therefore, recommended in these cases are:

Possible complications

Major reasons for moving away from broad-based endocarditis prophylaxis are the potential allergic reactions to the administered antibiotic, including fatal anaphylaxis, which are significantly reduced by the paradigm shift. In addition, the emergence of bacterial resistance to the administered antibiotic is curtailed.