Recommendations restricting the use of antibiotic prophylaxis before invasive dental procedures to only a handful of patient groups did not appear to increase rates of infective endocarditis caused by viridans group streptococci, researchers found.

Among 22 patients diagnosed with the infection over a 12-year period in Olmsted County, Minn., only three received the diagnosis after the restrictions were issued, according to Daniel DeSimone, MD, of the Mayo Clinic in Rochester, Minn., and colleagues.

And the rate was actually lower after the updated guidance was published than it was just prior to publication, although the declining trend did not reach statistical significance, the researchers reported online in Circulation: Journal of the American Heart Association.

“Nevertheless, limitations of the study, including a small annual number of infective endocarditis cases, mandate continued evaluation of incidence trends over an extended period of time, both locally and elsewhere, before concerns regarding increasing incidence of viridans group streptococci infective endocarditis related to changes in guidelines recommendations can be addressed fully,” the authors wrote.

The American Heart Association first issued formal guidelines for the use of infective endocarditis prophylaxis in patients with specific cardiovascular conditions undergoing certain dental procedures in 1955.

In 2007, the organization updated the guidance to restrict the use of antibiotic prophylaxis to a small number of at-risk patients, including those with underlying cardiac conditions conferring the highest risk of a poor outcome from infective endocarditis. Prophylaxis was no longer recommended for invasive gastrointestinal or genitourinary procedures.

To see whether the new guidance was associated with an increase in infective endocarditis caused by viridans group streptococci, which has been linked to invasive dental procedures, the researchers examined data on all definite or probable cases identified in the Rochester Epidemiology Project of Olmsted County from 1999 through 2010.

Read more about it here: