A new study, published in The Annals of Thoracic Surgery, warns that removing an infected tooth before heart surgery could increase the risk of major complications, including the risk of death prior to surgery.
Abscessed or infected teeth are often removed before heart surgery, as this decreases the risk of infection during surgery and decreases the risk of an inflammation of the inner layer of the heart - called endocarditis - following surgery.
But although it is standard practice to remove bad teeth prior to heart surgery, there is only limited evidence that supports this practice. The new study set out to evaluate what harms may be associated with dental extraction before cardiovascular surgery.
"Guidelines from the American College of Cardiology and American Heart Association label dental extraction as a minor procedure, with the risk of death or non-fatal heart attack estimated to be less than 1%," says study author and anesthesiologist Dr. Mark M. Smith, from the Mayo Clinic in Rochester, MN.
"Our results, however, documented a higher rate of major adverse outcomes, suggesting physicians should evaluate individualized risk of anesthesia and surgery in this patient population," he adds.
Heart attack, stroke, kidney failure and death
Dr. Smith and his colleagues found that 8% of patients who had teeth removed prior to heart surgery experienced adverse outcomes. These included heart attack, stroke, kidney failure and death.
Overall, 3% of patients died after dental extraction and before the heart surgery could take place.
But this study did have some limitations. Co-author and cardiac surgeon Dr. Joseph A. Dearani says:
"With the information from our study we cannot make a definitive recommendation for or against dental extraction prior to cardiac surgery. We recommend an individualized analysis of the expected benefit of dental extraction prior to surgery weighed against the risk of morbidity and mortality as observed in our study."
Established thinking on dental surgery and cardiac surgery is changing
The results of the Mayo Clinic study contribute to an ongoing departure in current thinking on the relationship between dental surgery and cardiac surgery.
"'Accepted wisdom' leads surgeons to request dental reviews prior to cardiac surgery in many thousands of patients annually around the world," says Dr. Michael Jonathan Unsworth-White, from Derriford Hospital in Plymouth, UK. "Dr. Smith's group asks us to question this philosophy. It is a significant departure from current thinking."
Writing in a linked comment, Dr. Unsworth-White draws parallels with another recent change of consensus. In patients undergoing dental work who have existing heart problems, it has previously been standard practice to prescribe prophylactic antibiotics.
Again, this was because there is a known link between dental bacteremia and endocarditis. But more recent studies have suggested that the potential side effects of these antibiotics may outweigh the benefits.
Dr. Unsworth-White explains:
"The American Heart Association and the National Institute for Health and Clinical Excellence in the UK have withdrawn support for this practice of prophylactic antibiotics because the danger from overuse of antibiotics outweighs any other potential risks. Regular tooth brushing, flossing, and even chewing gum are now recognized to dislodge as much, if not more, bacteremia than most dental procedures."
Recently, Medical News Today reported on a study that found 85% of post-surgery heart attacks go undetected due to a lack of symptoms.