Invasive dental procedures may raise the risk of rare but serious infections in people who have prosthetic heart valves, a recent French study suggests.
Some previous research has linked dental work to an increased risk of what's known as infective endocarditis - infections of the heart valve or lining - in people with prosthetic valves, but results have been mixed and inconclusive about whether antibiotics would prevent these infections.
For the current study, researchers examined data on 138,876 adults with prosthetic heart valves, roughly half of whom had at least one dental procedure during the study period. About 26 percent of the dental work involved invasive procedures, and patients received antibiotics in only half of these cases.
Patients who had invasive dental procedures were 66 percent more likely to develop these infections than people who didn't have invasive dental work, researchers report in The BMJ.
"Although the risk of infective endocarditis is low it is reasonable to offer the option of antibiotic preventive strategy prior to dental procedures because it is life threatening," said lead study author Sarah Tubiana of INSERM in Paris.
"Invasive dental procedures such as tooth extraction or scaling disrupt gingival integrity and allow bacteria in the mouth to enter the bloodstream; then, the bacteria can graft on cardiac valves and destroys valves," Tubiana said by email.
Infective endocarditis is a rare but severe disease that kills one in five people hospitalized for the condition and has a five-year mortality rate of 40 percent, researchers note.
Researchers followed half of the people in the current study for at least 1.7 years and during that time, 267 individuals developed endocarditis associated with streptococcus bacteria that live in the mouth.
The study team looked at endocarditis rates in the three-months after invasive dental work and compared infection rates to what happened to individuals who didn't have invasive dental procedures.
During the three months after invasive dental work, 5.1 percent of patients developed endocarditis, compared with 3.2 percent during periods without dental procedures.
Among people who had invasive dental procedures, the endocarditis rate was lower for those who got antibiotics at the time, but the difference was too small to rule out the possibility it was due to chance.
The study wasn't a controlled experiment designed to prove that dental work directly causes endocarditis or that antibiotics might prevent these infections.
Indeed, the authors note that while dental procedures were linked to slightly higher rates of these heart infections, they are not the main source of risk for heart valve patients, since the majority of infections across the entire study population occurred in people who didn't have recent dental work.
"Dental procedures are only one cause of infective endocarditis, and bacteria can get into the bloodstream simply during the course of daily life - for example through chewing or tooth brushing," said Dr. Tom Cahill, co-author of an accompanying editorial and a researcher at Oxford Heart Centre in the UK.
"The most important thing is that patients with valve disease are aware of endocarditis, and seek urgent medical attention if they are worried they have developed any of the symptoms," Cahill said by email.
Symptoms can be similar to the flu and include fever, sweats, chills and aching muscles or joints, he said. Some people with these infections may also have swollen glands, headache, cough, fluid buildup on the chest or legs or breathlessness.