Infective endocarditis is a rare condition with high morbidity and mortality. In 2008 the UK National Institute for Health and Clinical Excellence (NICE; now the National Institute for Health and Care Excellence) produced new guidance that recommended the complete cessation of antibiotic prophylaxis for patients undergoing dental procedures.
While the incidence of infective endocarditis has been slow increasing with time a 2014 paper Dayer el al reported an apparently higher rate of increase following the publication of the NICE guidance. Consequently, NICE undertook a review of the guideline to assess new evidence published since 2008.
Adults and children with structural cardiac defects at risk of developing infective endocarditis
- Healthcare professionals should regard people with the following cardiac conditions as being at risk of developing infective endocarditis:
- acquired valvular heart disease with stenosis or regurgitation hypertrophic cardiomyopathy previous infective endocarditis
- structural congenital heart disease, including surgically corrected or palliated structural conditions, but excluding isolated atrial septal defect, fully repaired ventricular septal defect or fully repaired patent ductus arteriosus, and closure devices that are judged to be endothelialised
- valve replacement. 
- Healthcare professionals should offer people at risk of infective endocarditis clear and consistent information about prevention, including:
- the benefits and risks of antibiotic prophylaxis, and an explanation of why antibiotic prophylaxis is no longer routinely recommended
- the importance of maintaining good oral health
- symptoms that may indicate infective endocarditis and when to seek expert advice the risks of undergoing invasive procedures, including non-medical procedures such as body piercing or tattooing. 
Prophylaxis against infective endocarditis
- Antibiotic prophylaxis against infective endocarditis is not recommended:
- for people undergoing dental procedures
- for people undergoing non-dental procedures at the following sites:
- upper and lower gastrointestinal tract genitourinary tract;
- this includes urological, gynaecological and obstetric procedures, and childbirth
- upper and lower respiratory tract; this includes ear, nose and throat procedures and bronchoscopy. 
- Chlorhexidine mouthwash should not be offered as prophylaxis against infective endocarditis to people at risk of infective endocarditis undergoing dental procedures. 
- Any episodes of infection in people at risk of infective endocarditis should be investigated and treated promptly to reduce the risk of endocarditis developing. 
- If a person at risk of infective endocarditis is receiving antimicrobial therapy because they are undergoing a gastrointestinal or genitourinary procedure at a site where there is a suspected infection, the person should receive an antibiotic that covers organisms that cause infective endocarditis. 
When they were introduced in 2008 the recommendation against any antibiotic prophylaxis for patients undergoing dental procedures was controversial but has now become routine. However differences in guidance between countries still persists helping to maintain the ongoing debate about who has the best approach. The recent Lancet paper by Dayer et al has contributed to this debate.
However, the full NICE guidance document has a very detailed critique of this paper and 6 out of 7 epidemiological papers considered for the review also demonstrate increasing incidence of infective endocarditis even in countries with more conservative antibiotic regimens than the UK. One of the research recommendations of the guidance is the establishment of a National register for infective endocarditis and this would facilitate research of this rare problem.
Dayer MJ, Jones S, Prendergast B, Baddour LM, Lockhart PB, Thornhill MH. Incidence of infective endocarditis in England, 2000-13: a secular trend, interrupted time-series analysis. Lancet. 2015 Mar 28;385(9974):1219-28. doi: 10.1016/S0140-6736(14)62007-9. Epub 2014 Nov 18. PubMed PMID: 25467569.