Q & A With Dr. Adam J. Waldman on Orlando Medical News

Q & A With Dr. Adam J. Waldman

By: ADAM J. WALDMAN, MD

My patient has mitral valve prolapse with moderate regurgitation and had taken antibiotics prior to dental visits for years. She heard that there were new guidelines. What is the current recommendation?

In the past, antimicrobial prophylaxis was recommended for a variety of procedures in patients with certain cardiac conditions. This is despite the fact that no prospective, randomized trial has ever proven that such therapy is beneficial. The previous recommendations were based upon guidelines published by the American Heart Association (AHA) in 1997. For many years, there has been considerable debate among healthcare providers on whom to give antimicrobial prophylaxis to, and whether or not it was efficacious. Due to this, the AHA revised their guidelines this year with several important changes.

In 1955, the AHA released its first guideline in regards to antimicrobial prophylaxis in regards to infective endocarditis (IE). Between 1955 and 1997, they released nine guidelines, which chronologically reflected changes in infectious patterns, patient characteristics, antibiotic resistance, and surgical advances. These guidelines seemed to become more complex, and contained more ambiguities with each subsequent publication. The most recent guidelines from 1997 risk stratified patients, according to their underlying cardiac condition and type of procedure (and subsequent risk of bacteremia).

Unfortunately, these guidelines have never been evidence-based, mainly because there has never been (and probably never will be) a randomized, placebo controlled, multicenter, double-blinded study specifically addressing this topic. Previous guidelines were mainly based on expert opinion and assumptions. If certain procedures cause bacteremia, and bacteremia can cause IE, which can be a potentially fatal illness, then why not give antibiotics to prevent this from happening?

Currently, your patient with mitral valve prolapse and MR would no longer be recommended for prophylaxis. There are other patients for whom endocarditis prophylaxis is no longer recommended, including patients with bicuspid aortic valves, acquired aortic or mitral valve disease (e.g., MVP with MR), and hypertrophic cardiomyopathy.

I have a patient with a previous aortic valve replacement with a mechanical valve prosthesis. The valve is functioning normally. Does the guideline change his endocarditis prophylaxis management?

No, your patient should still receive antimicrobial prophylaxis. Antibiotics are recommended for patients with the conditions listed (Table 1) who are undergoing dental procedures that involve the gingival tissues or periapical region of teeth or perforation of the oral mucosa. The list of GI, GU and other procedures contained by the new guidelines has diminished as well, and I would refer you to the full paper for complete details.

Whereas the prior guidelines recommended prophylaxis for patients with moderate to high risk conditions, the new guidelines recommend prophylactic therapy only for those patients with cardiac conditions that have the highest risk of adverse outcomes for IE.

Conditions where antimicrobial prophylaxis is recommended per the new guidelines:

Prosthetic heart valves, bioprosthetic and homograft valves.

Previous IE.

Unrepaired cyanotic congenital heart disease, including palliative shunts and conduits.

Completely repaired congenital heart defects with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first six months after the procedure.

Repaired congenital heart disease with residual defects at the site or adjacent to the site of the prosthetic device

Cardiac valvulopathy in a transplanted heart.

The oral antibiotic of choice for patients not allergic to penicillin is amoxicillin given as a single dose of 2 grams (for adults) given 30 to 60 minutes prior to the procedure. If unable to take oral, ampicillin is suggested. Patients with allergies to penicillin or ampicillin should be given either a first generation cephalosporin, clindamycin or a macrolide. If allergic, and unable to take oral, the recommended choice would be cefazolin, ceftriaxone, or clindamycin.

The new guidelines for IE prophylaxis have markedly changed with the recent release. What was the rationale for the current revision?
Several factors led to this current revision of the guidelines, which would decrease significantly the use of prophylactic antibiotics compared to before.

Rationale for current revision:

IE is much more likely to result from frequent exposure to random bacteremias associated with daily activities (eg, tooth brushing) than from the infrequent bacteremia caused by a dental, GI, or GU procedure.

Prophylaxis may prevent an exceedingly small number of cases of IE, if any, in individuals who undergo these procedures.

The risk of antibiotic-associated adverse events exceeds the benefit, if any, from prophylactic antibiotic therapy.

Maintenance of optimal oral health and hygiene may reduce the incidence of bacteremia from daily activities and is therefore more important than prophylactic antibiotics for a dental procedure to reduce the risk of IE.

Infective endocarditis is a relatively rare, but serious infection that has a significant amount of morbidity and mortality associated with it. Many fewer patients will receive antimicrobial prophylaxis under these new guidelines. There is sure to be considerable debate among healthcare providers and patients about these new guidelines. Each patient is recommended to discuss their individual case with their respective physician. I would highly suggest that all healthcare providers caring for these patients review the recently published guidelines for further details as this article only represents a brief synopsis.

Dr. Adam J. Waldman, board-certified in internal medicine and cardiology, joined Orlando Heart Center in July 2006.

September 2007