||The American Heart Association
(AHA) has reversed its recommendations for the prevention
of infective endocarditis (IE), an uncommon but potentially
lethal infection of the endocardium, which forms the lining
of the heart and heart valves.
||The AHA committee now recommends
that patients should normally not receive antibiotics before routine
dental work. The study demonstrated that dental procedures do not place
people at higher risk of IE.
||Brian L. Strom, MD, MPH,
Professor of Public Health and Preventive Medicine and Chair
of the Department of Biostatistics and Epidemiology at the University
of Pennsylvania School of Medicine, was a committee
member on this study.
||The new recommendations appear in the
most recent issue of Circulation: Journal of the American
(PHILADELPHIA) – In the most recent issue of Circulation:
Journal of the American Heart Association, the American
Heart Association (AHA) reverses its recommendations for the
prevention of infective
endocarditis (IE), an uncommon but potentially
lethal infection of the endocardium, which forms the lining of
the heart and heart valves.
In a dramatic reversal of 50 years of policy, the AHA committee now recommends
that patients should normally not receive antibiotics before
routine dental work. The only exceptions are those few at the greatest
risk of complications should they suffer from IE, such as those who have previously
had IE or heart-valve
replacement, since they are at the greatest risk of serious
adverse outcomes should IE occur.
Brian L. Strom, MD, MPH, Professor of Public Health and Preventive
Medicine and Chair of the Department of
Biostatistics and Epidemiology at the University
of Pennsylvania School of Medicine, and a committee member on this study,
comments on the new recommendations: “We questioned the wisdom of these
recommendations in the 1970s, but there was no way to generate the needed data
to determine whether or not they made sense. Then, in the 1990s, we finally were
able to do the needed study, and demonstrated that dental procedures do not place
people at higher risk of IE. As such, it makes no sense to give people antibiotics
when they have dental procedures.”
Strom continues, “Further, even if dental work were a risk factor, and
even if an antibiotic prevented IE, neither of which has been shown to be true,
the amount of disease that would have been prevented is vanishingly low. For
that, exposing 10 percent of the population to antibiotics twice a year is not
worth the risk.”
Since the bacteria that cause IE live in the mouth and in the intestines, physicians
thought that dental or intestinal procedures introduced bacteria into the blood
stream, which is how it was proposed to have reached the heart. By looking at
56 years of data on IE and its relationship to dental procedures – from
Strom and other groups – the AHA concluded that dental and intestinal procedures
were not a factor. People carry chronic infections in their mouths and intestines,
so simple activities such as teeth-brushing, eating, and going to the bathroom
can introduce the bacteria to the blood stream and can cause IE in a very small
portion of the population.
The AHA recommendations were first made in 1955 in Circulation based
on what was then thought to be a rational attempt to prevent a life-threatening
infection. Since then, and up until 1997, the AHA has continued to change
and refine their recommendations.
The review committee has found that the basis for the IE prophylaxis recommendations was not well established and that the quality of evidence
was limited to a few case studies. The 1997 recommendations acknowledged
that most cases of IE were not attributable to an invasive procedure but
instead from randomly occurring bacteria from routine daily activities.
“Giving someone too many antibiotics presents danger to individuals
and to society,” says Strom. “We’re becoming more resistant to bacteria as a whole, and over prescribing antibiotics is helping bacteria
evolve into organisms that we can’t treat.” It also puts individuals
at risk for allergic
and vomiting, and makes them resistant
to antibiotics that could be used to help them at another time.
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