What antibiotic prophylaxis is recommended for patients with heart valve replacements (HVR) prior to dental procedures to prevent infective endocarditis?

From the Guidelines

For patients with heart valve replacements (HVR) undergoing dental procedures, amoxicillin 2 grams orally taken as a single dose 30-60 minutes before the procedure is the standard antibiotic prophylaxis recommended to prevent infective endocarditis. This recommendation is based on the guidelines from the American Heart Association, as outlined in the 2007 and 2008 updates 1. For patients allergic to penicillin, alternatives include clindamycin 600 mg orally, azithromycin or clarithromycin 500 mg orally, or cephalexin 2 grams orally (if the penicillin allergy is not an anaphylactic-type reaction), all taken as single doses 30-60 minutes before the procedure.

Key Points to Consider

• Prophylaxis is specifically indicated for dental procedures involving manipulation of gingival tissue, the periapical region of teeth, or perforation of the oral mucosa.
• Patients with prosthetic heart valves are at higher risk for developing infective endocarditis because bacteria can more easily adhere to artificial valve materials, forming biofilms that protect the microorganisms from the immune system.
• The most common causative organisms are viridans group streptococci, which are abundant in the oral cavity and can enter the bloodstream during dental procedures.
• The short-term antibiotic coverage aims to eliminate these bacteria from the bloodstream before they can colonize the prosthetic valve.

Additional Considerations

• The American College of Cardiology and the American Heart Association have emphasized the importance of maintaining optimal oral health and hygiene to reduce the risk of infective endocarditis, as outlined in the 2008 guidelines 1.
• Other international societies, such as the British Society for Antimicrobial Chemotherapy, have published similar recommendations for the prevention of infective endocarditis 1.
• The 2020 review of guidelines for dental antibiotic prophylaxis highlights the evolution of recommendations over time, with a focus on high-risk patients and procedures 1.

High-Risk Conditions

• Prosthetic cardiac valve or prosthetic material used for valve repair
• Previous infective endocarditis
• Unrepaired and palliated cyanotic congenital heart disease
• Completely repaired congenital heart disease with prosthetic materials during the first 6 months after the procedure
• Repaired congenital heart disease with residual defects at or near the site of the prosthetic patch or prosthetic device.

From the Research

Antibiotic Prophylaxis for Heart Valve Replacement Patients

• The American Heart Association (AHA) recommends antibiotic prophylaxis for patients with heart valve replacements (HVR) prior to dental procedures to prevent infective endocarditis 2, 3.
• The recommended antibiotics include amoxicillin (2 g) or clindamycin (600 mg) administered an hour before the dental procedure 3.
• However, some studies suggest that amoxicillin/clavulanic acid and moxifloxacin may be more effective due to their broad-spectrum activity and low rates of antibiotic resistance 2.
• European recommendations suggest that patients at high risk, including those with valvular prostheses, should receive prophylaxis before dental procedures involving manipulation of the gums 3.
• Proper oral hygiene and regular dental checkups are also essential for at-risk patients to prevent infective endocarditis 3.

Dental Procedures and Antibiotic Prophylaxis

• Dental procedures that involve manipulation of the gums, such as extractions and scaling, can cause transient bacteraemia and increase the risk of infective endocarditis 4.
• Antibiotic prophylaxis should be administered before these procedures to reduce the risk of bacteraemia and subsequent endocarditis 3, 4.
• The use of erythromycin and clindamycin for prophylaxis has been studied, and both antibiotics have been shown to be effective in eliminating bacteraemia after dental extraction 5.

Controversies and Uncertainties

• There is ongoing debate about the effectiveness of antibiotic prophylaxis in preventing infective endocarditis, with some studies suggesting that the benefits may not outweigh the risks 6.
• The incidence of bacterial endocarditis is low, but the mortality rate is high, making it essential to weigh the potential benefits and harms of antibiotic prophylaxis 6.
• Further research is needed to determine the optimal antibiotic regimen and to clarify the role of antibiotic prophylaxis in preventing infective endocarditis in patients with heart valve replacements 6.