Prophylaxis against infective endocarditis: antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures

This guideline covers preventing infective endocarditis (IE) in children, young people and adults. It focuses on people at increased risk of infective endocarditis undergoing dental, gastrointestinal tract, genitourinary and respiratory tract procedures.

# Recommendations
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# 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 increased 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. 

# Patient advice
Healthcare professionals should offer people at increased 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 nonmedical procedures such as body piercing or tattooing. 

# Prophylaxis against infective endocarditis
Antibiotic prophylaxis against infective endocarditis is not recommended routinely:
for people undergoing dental procedures
for people undergoing nondental 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. The evidence reviews for this guideline covered only procedures at the sites listed in this recommendation. Procedures at other sites are outside the scope of the guideline (see the scope for details).
Chlorhexidine mouthwash should not be offered as prophylaxis against infective endocarditis to people at risk of infective endocarditis undergoing dental procedures. 

# Infection
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. # Context
Infective endocarditis is a rare condition with significant morbidity and mortality. It may arise after bacteraemia in a person with a predisposing cardiac lesion.
In the past, people at risk of infective endocarditis were given antibiotic prophylaxis before dental and certain nondental interventional procedures. However, Gould et al. (2006) and Wilson et al. (2007) recommended changes in clinical practice that aimed to limit the use of antibiotic prophylaxis in people having these procedures.
In 2008 NICE published a guideline to give clear, evidencebased guidance on best clinical practice for prophylaxis against infective endocarditis in people having dental and certain nondental interventional procedures. The guideline recommended that people at risk of infective endocarditis having interventional procedures (dental procedures, upper and lower respiratory tract procedures, upper and lower gastrointestinal tract procedures, genitourinary tract procedures) should not be offered antibiotic prophylaxis against infective endocarditis. It also recommended which patients with preexisting cardiac lesions should be regarded as at risk. These recommendations marked a further change from accepted practice.
The incidence of infective endocarditis has been shown to be increasing over time. The reasons for this are not well understood. However, in 2014 the Lancet published a paper that reported an increase in cases of infective endocarditis from 2000 to 2013, which showed a higher rate of increase following the publication of the NICE guideline (Dayer et al. 2015). In light of this paper, NICE felt it was important to assess any new evidence published since the 2008 NICE guideline. This evidence has been taken into account in the 2015 update of this guideline.# Recommendations for research
In 2008 the Guideline Committee made 3 recommendations for research.
As part of the 2015 update, the Standing Committee made an additional research recommendation on antibiotic prophylaxis against infective endocarditis, found in the addendum.

# National register of infective endocarditis
Infective endocarditis is a rare condition. The development of a national register of infective endocarditis in the UK to support research is recommended.
Why this is important
Such research would be facilitated by the availability of a national register that could offer data into the 'case' arm of proposed casecontrol studies and should be an anonymised database that would not require patient consent and hence more straightforward case ascertainment. Although it is a rare condition, it is likely that across the country there are enough patients to generate evidence from well conducted national studies.

# Cardiac conditions and infective endocarditis
What is the risk of developing infective endocarditis in people with acquired valvular disease and structural congenital heart disease?
Why this is important
Such research should use a populationbased cohort study design to allow direct comparison between groups and allow estimation of both relative and absolute risk.

# Interventional procedures and infective endocarditis
What is the frequency and level of bacteraemia caused by nonoral daily activities (for example, urination or defaecation)?
Why this is important
Such research should quantitatively determine the frequency and level of bacteraemia.

# Antibiotic prophylaxis against infective endocarditis
Does antibiotic prophylaxis in those at risk of developing infective endocarditis reduce the incidence of infective endocarditis when given before a defined interventional procedure?
Why this is important
There is limited evidence about the effectiveness of antibiotic prophylaxis in reducing the incidence of infective endocarditis in people at risk of developing infective endocarditis. The current evidence includes very limited data from observational studies with inconclusive findings. The study should be a randomised controlled trial with longterm followup comparing antibiotic prophylaxis with no antibiotic prophylaxis in adults and children with underlying structural cardiac defects undergoing interventional procedures. Outcomes should include the incidence infective endocarditis in those receiving prophylaxis compared to those not, and the incidence of adverse effects including anaphylaxis.