Discussion

This case highlights several issues related to the recent NICE guidelines on infective endocarditis which recommend no prophylaxis prior to dental procedures in at-risk patient groups. The prognosis for infective endocarditis remains poor, with high morbidity and mortality.1

Since the introduction of the NICE guidelines in 2008,2 the prescribing of antibiotic prophylaxis prior to dental procedures has declined dramatically. This has resulted in a 78.6% reduction in prescribing in 12 months as demonstrated by Thornhill et al.3 Although their study did not show an overall increase in the incidence of endocarditis following introduction of the new guidelines, it did acknowledge a background use of antibiotic prophylaxis of about 20% which would most likely have included patients who were thought to be at increased risk of endocarditis following a dental procedure, such as those with prosthetic heart valves, a prior history of endocarditis and significant congenital lesions.

This background use is thought to be largely driven by patients who are used to getting prophylaxis and are reluctant to stop despite the new guidelines, and clinicians such as cardiologists and general practitioners who are concerned about high risk patients. The lack of an increase in incidence could be because the patient population most at risk of developing infective endocarditis following a dental procedure was not included in the study as they continued to receive antibiotic prophylaxis despite the guideline change. Also, given that infective endocarditis is a rare diagnosis with an estimated incidence of 1.7–6.2 per 100 000 patient years,4 a longer period of surveillance is needed to accurately evaluate any increase in the incidence of infective endocarditis following the NICE guideline change.

In contrast to the NICE guidelines, the guidelines of the American Heart Association and European Society for Cardiology still recommend the use of antibiotic prophylaxis for those considered to be at high risk, which include patients with prosthetic heart valves undergoing dental procedures involving manipulation of the gingival or peri-apical region of the teeth or perforation of the oral mucosa.6 Both guidelines maintain that a high level of oral hygiene is necessary to prevent and minimise the risk of developing infective endocarditis; however, in patients with pre-existing dental disease this is not always possible and this subgroup has not been taken into account in any of the guidelines so far. We suggest that dentists in collaboration with cardiologists should be allowed to use their clinical discretion to determine which patients are at increased risk due to pre-existing comorbidities such as poor oral hygiene and prosthetic valves. Furthermore, prosthetic valve endocarditis has been shown in several studies to be associated with a poorer prognosis when compared to native valve endocarditis.7 ,8

Of interest, we note a recent letter in the British Dental Journal highlighting a small qualitative study of dentists within the NHS who felt obliged to follow NICE guidelines, despite over half believing that the American Heart Association guidelines would be more beneficial for their patients.9 ,10 According to the study, some dentists felt the need to comply with the NICE guidelines, despite their clinical judgement that certain patients warranted antibiotic prophylaxis, out of concern that their actions would be questioned as being against current guidelines.

The devastating consequences of infective endocarditis are demonstrated in this case, where prior to presentation the patient had had a dental procedure without antibiotic prophylaxis, although he had received antibiotic prophylaxis for 10 years with no previous adverse outcome.

This strongly suggests that the use of antibiotic prophylaxis in this case would have been justified given the patient's high risk cardiac status and pre-existing dental disease. We would suggest that the new guidelines should be reviewed for high risk patients, and that in the meantime decisions should be made by dental and medical professionals on a case-by-case basis, especially for at-risk patients.