skip to Main Content

Antibiotics before invasive dental work are helpful in high-risk patients

“These patients are divided between cardiologists and [their] dentists, so both parties have to play a role,” says one researcher.

Prophylactic antibiotics, when given to high-risk patients before they undergo invasive dental procedures, are linked to a lower likelihood of infective endocarditis (IE) in the following month, according to an observational study involving nearly 4,800 cases of IE.

For decades, antibiotic therapy has been used to treat the potential for IE in patients undergoing invasive dental procedures. But in rapid sequence beginning 15 years ago, three new guidelines arrived on the scene. In 2007, the American Heart Association (AHA) reduced the target of prophylaxis to only high-risk patients. In 2008, the UK’s National Institute for Health and Care Excellence went in a different direction, recommending against taking antibiotics, regardless of the risk. The European Society of Cardiology followed in 2009, issuing opinions in line with those of the AHA.

The new findings, published online this week in the Journal of the American College of Cardiologyprovide the strongest evidence to date supporting the AHA and ESC’s emphasis on prevention in the high-risk subgroup of patients, the researchers say.

“Our data supports this recommendation,” lead author Martin H. Thornhill, MBBS, BDS, PhD (University of Sheffield, England, and Carolinas Medical Center – Atrium Health, Charlotte, NC) told TCTMD. Previously, “the problem was that, although these guidelines exist, there was really no hard evidence to support the guidelines, neither in terms of a clear association between invasive dental procedures and endocarditis, nor in terms of effectiveness of antibiotics”. prophylaxis.”

Since a randomized controlled trial in this area would be unethical and expensive, Thornhill said, an observational analysis like this might be the best evidence available. He said he hopes that’s enough to influence practice – only a third of high-risk patients in the data set received antibiotic prophylaxis before their procedures. “Obviously there is a lot of room for improvement.”

Better communication between clinicians, greater patient awareness and tools like automatic reminders in electronic health records could help, he suggested. “These patients are divided between cardiologists and [their] dentists, both parties must therefore play a role in encouraging their patients to adopt oral hygiene and ensuring that those at high risk receive the appropriate antibiotic prophylaxis when needed.

With antibiotics, the risk of IE is reduced by half

Thornhill and colleagues analyzed data from 7,951,972 US patients who had commercial insurance/employer-provided Medicare supplemental coverage between 2000 and mid-2015. Among them, 3,774 were hospitalized with an IE, or 475 cases per million individuals.

About one-third of hospitalized individuals (34.2%) were at high risk for IE due to history of IE, prosthetic heart valve, prosthetic material used for valve repair, cyanotic congenital heart disease unrepaired or palliative shunt/conduit to treat congenital conditions. heart disease, or because they had undergone the repair of a congenital heart defect using prosthetic material within the last 6 months. The remaining 22.0% of patients were at moderate risk (due to rheumatic heart disease, non-rheumatic valve disease, congenital valve defects or hypertrophic cardiomyopathy) and 43.8% at low risk/ unknown. For the three groups, the adjusted incidence of AE within 30 days of a dental procedure was 467.6, 24.2 and 3.8 per million procedures.

The problem is that although these guidelines exist, there really isn’t any hard evidence to support the guidelines. Martin H. Thornhill

Most AEs occurred within 4 weeks. In a case-crossover analysis, in which each participant served as a control, high-risk patients were more likely to experience IE if they had undergone an invasive dental procedure within the previous 4 weeks (OR 2.00; CI in 95% 1.59-2.52). The risk was highest after dental extractions (OR 11.08; 95% CI 7.34-16.74) and oral surgery (OR 50.77; 95% CI 20.79-123.98) . Patients who underwent scaling, however, had a lower risk in the weeks following their procedure (OR 0.69; 95% CI 0.47-1.02). For those at moderate risk, there was no association between any of the dental procedures and the risk of subsequent IE.

The link between scaling and fewer cases of IE in high-risk patients was unexpected, the article notes, “because scaling is invasive and causes bacteremia equivalent to extractions.” Thornhill suggested that a possible explanation is that “people who have their teeth scaled regularly probably have good oral hygiene, which may protect them against endocarditis.”

Antibiotic prophylaxis was prescribed for 32.6%, 9.5%, and 2.9% of patients at high, moderate, and low/unknown risk, respectively.

High-risk patients who received antibiotics before their dental procedures had a lower risk of developing IE during the following 30 days (OR 0.49; 95% CI 0.29-0.85), with associations observed after extractions (OR 0.15; 95% CI 0.04-0.55) and, although not significant, after surgery (OR 0.08; 95% CI 0.01-1, 13). For moderate-risk patients, antibiotics were related to an overall reduction in IE after dental procedures (OR 0.34; 95% CI 0.14-0.88), but not when analyzed separately by type of intervention. A cohort analysis confirmed these associations in the high-risk group, but showed no association between antibiotics and IE in the moderate-risk group.

In an editorial, Ann Bolger, MD (University of California, San Francisco), and Dhruv S. Kazi, MD (Harvard Medical School, Boston, MA), warn that the analysis, although it addresses a key health clinical and public, has several limitations. The number of hospitalizations included represents a small portion of the more than 50,000 IE hospitalizations each year in the United States, the population includes only adults with employer-provided insurance, and the study period excludes the last 7 years, “a period when antibiotic-prophylaxis practices and the epidemiology of IE were changing rapidly,” they write.

More studies are needed to confirm these findings, Bolger and Kazi say, suggesting several potential avenues of research. “Whatever approach is chosen, we must continue to seek population-specific and representative information to inform antibiotic prophylaxis recommendations given the wide variation in IE risk, bacteriology and health systems between and within countries,” they advise, adding, “Providing antibiotic prophylaxis according to current recommendations can offer tangible benefits to high-risk patients today, even as we anticipate increasing guidelines refined and evidence-based in the future.

Back To Top