Avoiding endocarditis prophylaxis at your next dental appointment
Subacute bacterial endocarditis (SBE) is an infection that centers on the inner surfaces of the heart, usually on valvular tissue. Because the infection is so central, and affects such a vital part of the body and is extremely dangerous. Before the advent of antibiotics, this condition was always fatal. Since antibiotics have been discovered the mortality rates have decreased, but there still is quite a significant risk of morbid events. In fact, SBE is often discovered at the time of a major stroke. Because the infection is so deeply seated in the body, SBE requires six weeks of high dose intravenous antibiotic therapy to cure. As you might expect, this means a longer hospital stay than you might see in someone who undergoes valve replacement or coronary artery bypass grafting.
The good news is that heart valves or other heart tissue do not usually get infected unless there is something abnormal that makes the valve susceptible to infection. The valves most susceptible to infection are those that have been damaged by prior infection, are leaking (since childhood, or after a heart attack), or have been the site of prior surgery (reparative, or replacement), or by injury. Also, bacteria gets into our bloodstream on a regular basis without causing infection. Simple brushing of your teeth or flossing may cause bleeding and expose the circulation to bacteria. The immune system will usually destroy or inactivate these bacterial invaders as long as the dose of organisms is small. Because our immune systems are so good at destroying small doses of organisms to which we are exposed daily, there is no need to take antibiotics all of the time. In fact, if we were to do that we would expose ourselves to the side effects and allergies that antibiotics would cause along with the development of more resistant strains of organisms.
Due to the dangers of SBE, scientists thought for years that any procedure that would cause higher dose inoculations of organisms into the blood stream would risk infection to any "abnormal" heart valve. To try to prevent SBE, antibiotics were suggested for anyone with a "high" risk by virtue of a heart murmur or defect. Since ten to fifteen percent of the population was being diagnosed with a murmur at some point in their lives, an awful lot of antibiotic was being prescribed. But there was little proof that any protection was being provided. Once or twice in each decade since 1950 the recommendations for antibiotic prophylaxis have been revised, with the latest revision coming in 2007 as it had become apparent that the risk of antibiotic-related side effects had surpassed any apparent benefit in the large number of patients taking the antibiotics.
With respect to current recommendations for endocarditis prophylaxis for dental work, the following conditions are those with the greatest need for antibiotics:
- Prosthetic cardiac or material for valvular repair.
- Previous endocarditis.
- Cardiac transplant patients with valve disease.
- Congenital heart disease repaired using prosthetic material (only needed for first 6 months); repaired, but with a residual defect; or unrepaired cyanotic heart disease (including palliative procedures).
For people that have had to take antibiotics before dental work previously, I recommend that they discuss these recommendations with their individual health care providers. Whatever decisions are made with respect to antibiotics, one must understand that the best way to avoid endocarditis from dental procedures is to keep your teeth and gums healthy through proper oral hygiene.