What are the current indications for peri‑operative antibiotic prophylaxis to prevent infective endocarditis in patients with cardiac lesions such as prosthetic heart valves, prior endocarditis, specific congenital heart diseases, or cardiac transplant with valvular abnormalities?

Antibiotic Prophylaxis for Infective Endocarditis Before Surgery

Antibiotic prophylaxis to prevent infective endocarditis is reasonable only for the highest-risk cardiac patients undergoing dental procedures that manipulate gingival tissue or perforate oral mucosa; prophylaxis is NOT recommended for gastrointestinal, genitourinary, or other non-dental surgical procedures, even in patients with prosthetic valves or prior endocarditis. 1, 2

Highest-Risk Cardiac Conditions Requiring Prophylaxis

Prophylaxis should be considered only for patients with the following cardiac conditions (Class IIa recommendation): 1, 3

• Prosthetic cardiac valves or prosthetic material used for cardiac valve repair 1, 3
• Previous history of infective endocarditis 1, 2
• Unrepaired cyanotic congenital heart disease, including palliative shunts and conduits 1, 4
• Completely repaired congenital heart defects with prosthetic material (surgery or catheter-based), but only during the first 6 months after the procedure 1, 4
• Repaired congenital heart disease with residual defects at or adjacent to prosthetic patches or devices that inhibit endothelialization 1, 4
• Cardiac transplant recipients with valve regurgitation due to structurally abnormal valves 1, 2

Procedures Requiring Prophylaxis

Dental Procedures ONLY

Prophylaxis is indicated only for dental procedures involving: 1, 3, 2

• Manipulation of gingival tissue 1, 3, 2
• Manipulation of the periapical region of teeth 1, 3, 2
• Perforation of the oral mucosa (including scaling and root canal procedures) 1, 2

Prophylaxis is NOT needed for: 1, 3, 2

• Local anesthetic injections in non-infected tissue 1, 2
• Treatment of superficial caries 2
• Removal of sutures 1, 2
• Dental X-rays 1, 2
• Placement or adjustment of removable prosthodontic or orthodontic appliances 1, 2
• Shedding of deciduous teeth 1, 2

Non-Dental Procedures: NO Prophylaxis

Critical distinction: Prophylaxis is NOT recommended for any of the following procedures, even in the highest-risk patients: 1, 4, 2

• Gastrointestinal procedures (gastroscopy, colonoscopy, esophagogastroduodenoscopy) 1, 2
• Genitourinary procedures (cystoscopy) 1, 2
• Respiratory procedures (bronchoscopy, laryngoscopy, endotracheal intubation) 1, 2
• Transesophageal echocardiography 1, 3, 2
• Vaginal or cesarean delivery 4, 2

This represents a major shift from older guidelines, as there is no convincing evidence that infective endocarditis is related to these procedures. 4, 2

Recommended Antibiotic Regimens for Dental Procedures

Standard Regimen (No Penicillin Allergy)

Amoxicillin 2 grams orally, given 30-60 minutes before the procedure 1, 3, 4, 2

• For children: 50 mg/kg orally 1, 2
• If unable to take oral medication: Ampicillin 2 grams IV/IM (adults) or 50 mg/kg IV/IM (children) 2

Penicillin Allergy

Clindamycin 600 mg orally or IV, given 30-60 minutes before the procedure 1, 3, 2

• For children: 20 mg/kg 1, 2
• Alternative options: Cephalexin 2 grams orally, OR azithromycin/clarithromycin 500 mg orally 4
• Avoid cephalosporins in patients with anaphylaxis, angioedema, or urticaria after penicillin exposure 1

Cardiac Surgery-Specific Prophylaxis

For patients undergoing cardiac surgery with prosthetic valve placement or prosthetic intravascular materials, perioperative prophylaxis is directed against staphylococci: 1

• First-generation cephalosporin is most commonly used (Class I, LOE A) 1
• Initiate immediately before the procedure 1
• Continue for no more than 48 hours postoperatively to minimize emergence of resistant organisms 1
• In hospitals with high prevalence of methicillin-resistant Staphylococcus aureus, vancomycin may be considered, though not proven superior to cephalosporins 1

Critical Pitfalls to Avoid

Patients already on chronic penicillin therapy (e.g., for rheumatic fever prophylaxis) likely harbor penicillin-resistant oral flora. 1 For these patients:

• Select clindamycin, azithromycin, or clarithromycin instead 1
• Avoid cephalosporins due to possible cross-resistance 1
• Ideally, delay dental procedures until 10 days after completing antibiotic therapy to allow normal oral flora to reestablish 1

Patients on anticoagulation: Avoid intramuscular injections for prophylaxis (Class I, LOE A). 1 Use oral regimens whenever possible, or intravenous antibiotics if unable to tolerate oral medications. 1

Coronary artery bypass graft or coronary stents: These patients do NOT require endocarditis prophylaxis for dental procedures (Class III, LOE C). 1

Rationale for Restrictive Guidelines

The dramatic narrowing of prophylaxis indications reflects several key principles: 2

• Infective endocarditis is more likely from daily activities causing random bacteremias (tooth brushing, chewing) than from medical/dental procedures 2
• Prophylaxis may prevent an exceedingly small number of cases, if any 2
• The risk of antibiotic-associated adverse effects exceeds the benefit from prophylactic therapy in lower-risk patients 2
• Optimal oral hygiene and regular professional dental care are more important than procedural prophylaxis for reducing endocarditis risk 3, 2

Patients should eliminate potential sources of dental sepsis at least 2 weeks before valve implantation when possible. 3