To the Editor,
The association between heart disease and the development of infectious endocarditis (IE) has been known since the beginning of the last century. In 1909, Horder discovered the association between dental hygiene and IE.1 For many years, the practice of dental antibiotic prophylaxis has been recommended in most patients with prostheses, valvular heart disease, or congenital heart disease. As the incidence and mortality of IE have not changed during this period, the role of such measures has become a matter of debate. Thus, clinical guidelines have restricted the indications to high-risk procedures and high-risk patients.2 The aim of this study was to determine the degree of knowledge of IE prophylaxis among Spanish dentists.
Between September 2011 and October 2011, we conducted a telephone survey of 2 oral health professionals from each of the 52 Spanish provinces. The sample was randomly selected from the Yellow Pages listing. Table 1 shows the list of questions. We interviewed 104 dental specialists: 50 (48.5%) dental physicians, 50 (48.5%) odontologists, and 4 (3%) maxillofacial surgeons. Their work experience was 19.1 (8.8) years. One hundred (97%) of the respondents considered IE to be fatal. Nevertheless, only 8 respondents thought that mortality could exceed 50%; 94 respondents (91.3%) recognized that IE prophylaxis was important or very important and routinely provided it in their clinical practice according to their own criteria. In total, 84.6% considered that cardiologists were accessible or reasonably accessible, but only 12% routinely consulted one to make a decision. A total of 54% stated that patients who needed prophylaxis did not attend their clinic with a recommendation for prophylaxis. Table 2 shows the cardiac conditions requiring antibiotic prophylaxis according to the respondents.2 In total, 93% stated they were unaware of the guidelines on the prevention of IE. In addition, 54 (56.1%) thought that the message from the cardiology community is vague and changeable. Only 27 dentists (25.9%) completely agreed with the restrictions included in the updated guidelines.2
Table 1. List of Questions.
| What academic qualifications do you have? |
| How many years have you been working in your profession? |
| Do you think that infective endocarditis can be fatal? What percentage? |
| What role do you think infective endocarditis prophylaxis has in dental procedures? |
| Do you use prophylaxis at your discretion or do you require a cardiologist's report? |
| Do patients attend your clinic with recommendations for infective endocarditis prophylaxis? |
| Do you think prophylaxis is needed in the following cases? |
| Coronary artery bypass grafting |
| Coronary stent |
| Cyanotic congenital heart disease |
| Innocent murmur |
| Mechanical valve prostheses |
| Mitral valve prolapse |
| Heart failure |
| How do you rate access to cardiologists to discuss your questions? |
| How do you rate the message from the cardiology community regarding infective endocarditis prophylaxis? |
| Do you know of the NICE/AHA/ESC guidelines on the prevention of infective endocarditis? |
| What is your opinion of the virtual disappearance of prophylaxis in dental procedures in the latest clinical practice guidelines? |
AHA, American Heart Association; ESC, European Society of Cardiology; NICE, National Institute for Clinical Excellence.
Table 2. Indication for Prophylaxis According to Heart Condition.
| Type of heart condition | Correct answer | Result |
| Coronary artery bypass grafting | No | 37 (35.6) |
| Coronary stent carriers | No | 42 (40.4) |
| Heart failure | No | 29 (27.9) |
| Innocent murmur | No | 82 (78.9) |
| Mitral valve prolapse | No | 39 (37.5) |
| Mechanical valve prostheses | Yes | 98 (94.2) |
| Cyanotic congenital heart disease | Yes | 75 (72.1) |
| Average | 57.4 (55.2) |
Data are expressed as no. (%).
Several studies on native-valve IE and prosthetic-valve IE have demonstrated a change in the epidemiology of this disease. This entity affects an older population and is associated with the increased use of invasive techniques; a decrease in the cases of streptococcal infection and an increase among patients with a structurally normal heart has been observed.3, 4 In addition, several studies have shown that daily activities such as chewing gum or tooth brushing can cause transient bacteremia.2 Based on the foregoing, the guidelines on the prevention of IE have increasingly restricted the indications for prophylaxis.
Since more than 90% of the respondents were unaware of these consensus guidelines, prophylaxis is probably being applied unnecessarily to patients with heart disease (more than 60% of respondents), patients with any type of mitral valve prolapse (65%) and patients with heart failure (40%). Proper indication in cases such as prosthetic valves or congenital heart disease remained high (75%), although it was slightly lower than in similar studies, where proper indication reached 80%.5 The sources of information used by these professionals were journals or dentistry bulletins.
Most dentists thought that the message from the cardiology community is changeable and vague. Given that more than 80% stated that cardiologists are accessible or reasonably accessible, and that most considered the role of prophylaxis to be very important, we may be facing a serious communication problem between cardiologists and professionals in this field, since we are not obtaining the intended effect.
There may also be a medicolegal reason for this situation.6 In Spain, dentistry is one of the liberal professions, and although it seems clear when prophylaxis should be indicated and in whom, there is a broad spectrum of patients, including specific groups (pregnant women, children, etc.) in whom IE can be fatal and thus minimizing the risk is prioritized.
In conclusion, the degree of knowledge of IE and the correct indications for antibiotic prophylaxis among oral health professionals in Spain is poor. These findings suggest the need to increase knowledge of the guidelines on IE prevention among Spanish dentists and to establish new channels of communication such that the message from various scientific communities has its intended effect.
Corresponding author: ftorressaura@gmail.com