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Infective Endocarditis and Current Premedication Prophylaxis Guidelines

INFECTIVE ENDOCARDITIS

Overview

Infective endocarditis is associated with microbial infection of the endocardial surface of the heart. The valves are particularly affected with vegetation that contains bacteria, platelets, and inflammatory cells. Infective endocarditis can present as acute bacterial endocarditis (ABE) or subacute bacterial endocarditis (SBE).

Premedicating the patient prior to dentistry, when premedication is called for or required, can prevent infective endocarditis. Premedication provides a high level of a recommended antibiotic in the blood prior to the dental procedure, and this helps destroy any bacterium that enters the bloodstream during invasive dentistry.

Acute Bacterial Endocarditis (ABE)

ABE is an aggressive type of endocarditis with galloping symptoms. It occurs within approximately seven days of an invasive dental procedure done without premedication, when premedication is required. ABE is common in the elderly and in IV drug users. Staphylococcus aureus, viruses, and fungi are the most common offending organisms causing ABE.

Subacute Bacterial Endocarditis (SBE)

SBE is the most common form of infective endocarditis, and streptococcus viridans is the most common offending organism. Symptoms and signs usually present insidiously within 2–3 weeks after an invasive dental procedure done without premedication, when premedication is required. SBE presentation can also occur 2–3 months later.

Infective Endocarditis Clinical Features

It is quite common for patients to experience “flu-like” symptoms at the start of the endocarditis. The symptoms associated with ABE are rapidly progressive; those associated with SBE are gradual in onset. Fever, anorexia, malaise, weight loss, night sweats, salmon-colored urine or hematuria, conduction abnormalities, new valvular regurgitation, and CHF are common findings associated with infective endocarditis.

Splinter hemorrhage of the fingernails, Roth’s spots (retinal hemorrhages), Osler’s nodes (painful red bumps on the fingertips), and Janeway lesions (nontender hemorrhagic nodules on the palms and soles) are common peripheral signs associated with infective endocarditis.

Infective Endocarditis Treatment

Any patient presenting with ABE or SBE is immediately hospitalized for treatment of the systemic infection and associated vital organ involvements. A maximum of three blood cultures are obtained to determine the offending organism (bacterial/viral/fungus), and the specific infection is then aggressively treated for 2–3 weeks with intravenous (IV) antibiotics (penicillin plus gentamycin, or vancomycin in the penicillin-allergic patient), antivirals, or antifungals, depending on the outcome of the blood cultures.

Symptomatic care is additionally provided for the associated symptoms and vital organ involvements (heart and kidneys). Post recovery, all patients with a past history of infective endocarditis (ABE or SBE), with or without valvular problems, must be premedicated prior to all invasive dental procedures, per the 2007 American Heart Association (AHA) guidelines. Any antibiotic listed in the AHA premedication guideline protocol can be used, depending on the patient’s allergy status and DDI with the patient’s routine medication list (Table 21.1).

Table 21.1 2007 American Heart Association (AHA) Recommended Antibiotic Prophylaxis Regimen

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PREMEDICATION PROPHYLAXIS

Conditions That Require AHA Premedication Prophylaxis

• Prosthetic heart valves
• Past history of infective endocarditis
• Unrepaired or incompletely repaired cyanotic congenital heart disease, including those with palliative shunts or conduits
• A completely repaired congenital heart defect with prosthetic material or device, during the first 6 months after the repair procedure. This is because epithelial overgrowth of the graft material usually occurs within the first 6 months of repair.
• Any repaired congenital heart defect with persistent residual defect at the site or adjacent to the site of a prosthetic patch or a prosthetic device. This defect is usually confirmed with an echocardiogram.
• Cardiac transplant patients who develop heart valve–associated problems.

In addition to the aforementioned conditions outlined by AHA as needing antibiotic premedication prophylaxis some non-cardiac conditions also require antibiotic premedication prophylaxis:

• Systemic intracranial hydrocephalic shunt: ventriculoatrial (VA) or ventriculovenous (VV).
• Systemic hemodialysis shunts (arteriovenous catheter or arteriovenous synthetic graft shunt): Do not monitor the blood pressure or draw blood from the arm with the shunt.
• Peritoneal dialysis: Only if the patient has an indwelling catheter.
• Synthetic graft materials (Dacron, Teflon, etc.) when used for extracardiac vascular repairs, as with aortic aneurysm and so on. Epithelial overgrowth of the graft material is never 100%, and some areas may stay denuded and promote infective endocarditis.
• Patients receiving cancer drugs through an infuse port or a Hickman catheter line.
• Patients with a history of cirrhosis and associated ascites need to be premedicated per AHA guidelines. The ascitic fluid is a good medium that can promote bacterial growth and increase the risk of infective endocarditis.
• Prosthetic joints: Per the December 2012 joint evidence-based clinical practice guideline (CPG) statement issued by the American Dental Association (ADA) and the American Academy of Orthopedic Surgeons (AAOS), there is “limited” evidence for joint prosthesis premedication prophylaxis in non-high-risk patients. “Limited” or “weak” evidence means that there is no real advantage in providing or not providing joint prosthesis prophylaxis. The dental provider should use his or her judgment for limited recommendations and independently decide on a case-by-case basi/>
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