Printed on: October 23rd, 2026

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Infective endocarditis and antibiotic prophylaxis in primary care

When NICE guidance arrives at Red Whale, summarising it into something brief, yet useful, can be a challenge. The NICE guidance on antibiotic prophylaxis of infective endocarditis, however, initially filled us with joy because we were able to summarise it in just one word! Who needs endocarditis prophylaxis? Nobody!

However, since that guidance was last fully updated, evidence has been mounting. New European guidelines were released in 2023, taking a different stance from NICE.

What might have been a quick and easy response to an online or in-person enquiry has become more complicated and time-consuming because the answer is now, ‘It depends…’.

Sadly, there isn’t a short answer; this will require discussion, explanation and shared decision-making! 

However, Red Whale is here to help. Here is our outline of the changing landscape of endocarditis, with a compare and contrast summary of the NICE guidance and the primary care-relevant information from the European Society of Cardiology (ESC) Guidelines for the management of endocarditis, providing the learning you’ll need for a successful consultation (EHJ 2023;44:3948, NICE 2008 (updated 2016), CG64).

This article was updated in October 2026.

• Infective endocarditis is rare but serious, and is increasing:
  • Global incidence has risen gradually over the past 20 years to 13.8/100 000/y in 2019; that is one case/GP/4 years, or one case/average GP practice every year! (Lancet 2024;404:377)
  • Mortality is 30% in the first year (Lancet 2024;39:100876).
• Infective endocarditis happens when bacteria settle and replicate in the heart to form a ‘vegetation’, usually on the heart valves.
• People with damage to the cardiac endothelium (including those with prosthetics within the heart – not just valves, but also implantable electronic devices and ventricular assist devices) or those who are immunosuppressed are at increased risk of infective endocarditis (Lancet 2024;404:377).
• Among younger age groups, congenital heart disease (either treated with prosthetic materials or untreated) and  intravenous drug use are significant risk factors (Lancet 2024;404:377).
• Streptococci that are commonly found in the mouth are the cause in 20–40%. Poor oral hygiene is a risk factor, as are invasive dental procedures (ones that disrupt gingival integrity and allow bacteria into the bloodstream) (BMJ 2017;358:j3942).
• Antibiotics have been shown to reduce post-dental procedure bacteraemia. There has been a lack of evidence supporting an effect on reduction of endocarditis, but recent studies and meta-analyses suggest some efficacy (Lancet 2024;39:100876, Lancet 2024;404:377).

• Prior to the 1980s, infective endocarditis mainly affected young adults with underlying cardiac abnormalities from congenital or rheumatic heart disease. This is still the case in low-income countries (Lancet 2024;404:377).
• Since the 1980s, greater availability of prosthetic heart valves, intracardiac pacemakers and other implantable devices in high-income countries has led to a more elderly and multi-morbid affected population (Lancet 2024;404:377).
• Hospitalisations for endocarditis associated with intravenous drug use have increased rapidly over the past 20 years (Lancet 2024;404:377).
• The microbiology has also altered; more cases are now due to staphylococcus organisms compared with the mainly streptococcal and enterococcal infections previously. The proportion of infections with resistant organisms has increased (Lancet 2024;404:377).
• Incidence is higher in men than women, but women have poorer outcomes and a higher mortality-to-incidence ratio. The reason for this is unknown (Lancet 2024;404:377).
• In low- and middle-income countries, people with endocarditis have higher rates of complications (e.g. heart failure) and higher mortality than those in high-income countries (Lancet 2024;404:377).

• Endocarditis is difficult to diagnose. 
• Older, multi-morbid patients and the higher proportion of cases due to staphylococcal organisms have made the classical presentation less common.
• It may present as an acute, rapidly-progressive infection. However:
  • The subacute presentation, with or without the various eponymous signs beloved of medical textbooks, although less frequent, may still occur. 
  • It may even present as a chronic disease with non-specific symptoms and no fever (EHJ 2023;44:3948, Lancet 2024;404:377).

Diagnosis is complicated and depends on clinical findings, microbiological tests and imaging results.

The ESC guidance covers the full scope of endocarditis management, whereas the NICE guidance is focused on prophylaxis (EHJ 2023;44:3948, NICE 2008 (updated 2016), CG64). The ESC goes into a bit more detail about the features of high- and intermediate-risk patients, and there are clear differences in the recommendations. 

In 2008, NICE, while acknowledging that some people have an increased risk of endocarditis, said that “People should not be offered endocarditis prophylaxis”. This became “People should not routinely be offered endocarditis prophylaxis” when the guideline was updated in 2016. However, NICE did not give any indication of what was ‘routine’ and when and who might fall outside this guidance – which wasn’t very helpful! 

In the meantime, the Scottish Dental Clinical Effectiveness Programme (SDCEP) produced a resource for dentists (initially published 2018, updated 2026) which differs from NICE’s advice. It is based on the ESC guidance, and identifies people at high-risk who should be offered prophylaxis (SDCEP 2026). 

Then, in 2024, NICE performed an exceptional review which acknowledged the perceived unhelpfulness of the 2016 update; it stated that linking to the SDCEP recommendations would help clarify who might merit special consideration for antibiotic prophylaxis.

There is considerable overlap in risk groups defined by NICE and ESC, but there are also some important differences. The ESC classifies conditions into different levels of risk and makes specific recommendations for different risk profiles. NICE lists at-risk groups, but does not subdivide degrees of risk, and makes one broad recommendation for all.

The next two tables outline what each guideline says about risk groups and how they differ.

Alternatively, skip to the end of this section for a quick Red Whale bottom line.

The bottom line

Remember that the NICE guidelines now link to the SDCEP guidelines, which UK dentists are being advised to follow, and which are based on the ESC guidelines. 

Therefore:

(The SDCEP guidance groups heart transplant in with high-risk patients due to the fact that antibiotic prophylaxis may be considered in this group. We have chosen here to reflect the ESC guidance on high-risk and intermediate-risk categories. However, be aware that dental colleagues may refer to heart transplant as high risk when communicating with us).

A note about at-risk patients with replacement valves

ALL SURGICAL HEART VALVE REPLACEMENTS ARE HIGH RISK FOR ENDOCARDITIS. 

ALL AORTIC AND PULMONARY VALVE TRANSCATHETER REPLACEMENTS ARE HIGH RISK FOR ENDOCARDITIS.

Both NICE and ESC agree: ALL types of replacement aortic and pulmonary heart valve are high risk for endocarditis, whether mechanical or tissue, and whether they had a surgical or transcatheter implantation. The shorter anticoagulation recommendations for tissue vs. mechanical valves, and for transcatheter-implanted vs. surgically-implanted valves, do NOT correlate with any lowering of endocarditis risk.

To confuse matters a little, the ESC stopped short of an absolute recommendation for antibiotics in people with transcatheter atrioventricular (mitral or tricuspid) valve replacements due to a lack of data on endocarditis risk. Antibiotic prophylaxis for this group SHOULD BE CONSIDERED, rather than being RECOMMENDED.

NICE does not specify which procedures should be considered risky. 

However, the ESC lists the following as at-risk dental procedures (EHJ 2023;44:3948):

• Dental extractions.
• Oral surgical procedures, including periodontal surgery, implant surgery and oral biopsies.
• Procedures involving manipulation of the gingival or periapical region of the teeth, including scaling and root canal procedures.

In contrast to NICE, the ESC also advises that antibiotic prophylaxis may be considered for high-risk patients undergoing an invasive diagnostic or therapeutic procedure of the respiratory, gastrointestinal, genitourinary, skin or musculoskeletal systems.

• Many cases (up to half) of endocarditis occur in people with no previously identified heart problems (NICE 2008 (updated 2016), CG64).
• Toothbrushing produces a greater bacteraemic risk than any dental procedure.
• At the time that the NICE guideline was written:
  • The assumption had been that prophylaxis reduced the risk of endocarditis, but there was no evidence to prove this; indeed, there was some evidence it did not.
  • Cohort studies showed a poor temporal relationship between timing of the procedure and development of endocarditis (sometimes a time lag of many, many months).
  • Some studies showed that in someone with an 'at-risk' heart, the chance of developing endocarditis was no higher in those having a procedure than in those not having one – suggesting it was the heart, not the procedure, that was the key factor.
  • There was a concern that deaths from anaphylaxis due to antibiotics might outweigh deaths prevented with antibiotics, particularly if prophylaxis was overprescribed. 

A systematic review of 18 European studies has reported that endocarditis incidence has doubled over 20 years (Open Heart, 2021;8:e001846). This is likely due to multiple factors, including (Lancet 2024;39:100876):

• Rising numbers of elderly in the population.
• Increasing cardiovascular device implantation (and therefore more people being at high risk of endocarditis).
• More illicit injection drug use.
• More access to diagnostic imaging (so more conclusive diagnoses).
• Better coding of diagnosis in records.
• Increased awareness of infective endocarditis.

It is therefore difficult to determine the contribution of restriction of antibiotic use to the rising level, although this trend contrasts with a relatively stable incidence in the US (Lancet 2024;39:100876). 

In the UK, a study looked at the incidence of infective endocarditis (based on HES data and antibiotic prescribing) before and after the NICE guidelines were introduced (Lancet 2015;385:1219). Since the NICE guidance came out, there has been:

• An 88% reduction in the use of antibiotic prophylaxis for endocarditis (90% of these antibiotics are prescribed by dentists).
• An increase in cases of endocarditis (over and above the historical trend); this amounts to an extra 35 cases/month in England or 0.11 extra cases/10 million people/month.
• The increased risk was seen both in those considered to be at high risk AND in those considered to be low risk (who probably would never have been offered prophylaxis even before the guidelines were introduced).

The authors and the accompanying editorial highlighted many potential problems with the study (Lancet 2015;385:1164): 

• These findings do not show causation. 
• There are other possible reasons for the apparent increased incidence; for example, more people at high risk and more procedures undertaken on these individuals.
• The data being used (HES statistics), which is problematic for a whole variety of reasons.
• Most prophylaxis was given for dental procedures so, if the change is due to changes in prescribing due to dental procedures, there should be a reduction in cases of oral streptococcus endocarditis but no change in other causative organisms; however, this data was not captured/available.

Both the authors and the editorial advised caution, calling for more data before any change in management recommendations.

Most studies prior to the NICE guidelines (almost all were observational or case–control studies) showed no link between dental procedures and infective endocarditis. However, many of these trials were underpowered. No randomised control trials had been done, and because the American and European guidance recommends antibiotic prophylaxis in the highest-risk populations, it is difficult to know whether a placebo-controlled trial would pass ethical committee approval. Such a trial would also need to be very large because the incidence is so low, so costs would be enormous.

Much of the evidence since the NICE guideline was published has come from cohort and case-crossover studies. In case-crossover studies, people act as cases and their own controls at different time points, offsetting confounding due to inter-individual variation.

Two large studies were conducted in the US and published in 2022 and 2023 (Lancet 2024;39:100876):

• In both of these combined case-crossover and cohort studies, over 65% of invasive dental procedures performed in high-risk patients were NOT covered by antibiotic prophylaxis (contrary to US guidelines). This, therefore, allows any association between dental work and endocarditis to be unmasked.
• The first study (of 3774 endocarditis patients with employer-provided medical and dental insurance cover) found a significant association between invasive dental procedures and development of endocarditis in the following 30 days in patients at high risk (odds ratio 2.0, CI 1.6–2.5), particularly extractions (odds ratio 11.1, CI 7.3–16.7) and oral surgical procedures (odds ratio 50.8, CI 20.8–124.0).
• This study also had a cohort study element of nearly 8 million patients which also found increased odds of contracting endocarditis in the 30 days after extractions (odds ratio 9.2, CI 5.5–15.9) and oral surgical procedures (odds ratio 20.2, CI 11.2–36.7) in high-risk individuals.
• The second US case-crossover study was undertaken in 2647 Medicaid patients who had endocarditis. It again found increased odds of high-risk patients developing endocarditis within 30 days after invasive dental procedures (extractions odds ratio 3.7, CI 2.7–5.3; oral surgical procedures odds ratio 10.7, CI 5.2–21.9).
• The linked 1.68 million patient cohort study also indicated an association (extractions odds ratio 14.2, CI 5.4–52.1; oral surgical procedures odds ratio 30.0, CI 9.6–119.3). 

Similar findings have also been seen in a Taiwanese self-controlled case study; a study using the Korean national database of patients with implanted cardiac electrical devices; and a UK nationwide case-crossover study of dental procedures performed in hospital outpatients. Therefore, evidence of an increased risk of infective endocarditis following invasive dental procedures is building (Lancet 2024;39:100876).

So far, only the two US case-crossover and cohort studies discussed in the previous section have been able explore the effect of antibiotic prophylaxis on endocarditis because the other studies were unable to identify whether specific procedures were covered by prophylaxis or not (Lancet 2024;39:100876).

• Antibiotic prophylaxis significantly reduced incidence of endocarditis following invasive dental procedures in high-risk patients with employer-provided medical and dental cover (odds ratio 0.4, CI 0.2–0.6).
• High-risk Medicaid patients in the cohort study given antibiotic prophylaxis also had significantly reduced endocarditis incidence after invasive dental procedures (odds ratio 0.2, CI 0.1–0.5). However, this beneficial effect did not reach significance in the case-crossover study (odds ratio 0.5, CI 0.2–1.5).
• The Medicaid study results suggest that one case of endocarditis could be prevented by providing antibiotic prophylaxis to 244 high-risk patients undergoing invasive dental procedures, 143 high-risk patients undergoing dental extractions or 71 high-risk patients undergoing oral surgical procedures. 

NICE estimated 20 fatal adverse drug reactions (ADRs) per million prescriptions using data from 1968 and 1984, and a rate of non-fatal ADRs of 20 000/million prescriptions based on 1997 figures. These figures were for all doses of all types of penicillins, administered by all routes (NICE 2008 (updated 2016), CG64).

Newer UK data specifically targeting standard 3g doses of oral amoxicillin used for antibiotic prophylaxis suggested a much better safety profile, with no fatal ADRs reported after 3 million prescriptions and 22.6 non-fatal ADRs per million prescriptions (Lancet 2024;39:100876).

The dentist is usually responsible for prescribing antibiotic prophylaxis for planned at-risk dental procedures (SDCEP, 2026).

The following table contains the oral antibiotic regimens recommended in the ESC guideline (EHJ 2023;44:3948). The antibiotics in bold type are also recommended in the SDCEP, 2026 guidance. Although the NICE guideline does not fully endorse prophylaxis, it does signpost to the SDCEP website (NICE 2008 (updated 2016), CG64). Therefore, we are likely to see these being prescribed by our dental colleagues. Antibiotics are usually given 30–60 minutes before the dental procedure (SDCEP, 2026). 

Antibiotics are the cause of much debate, but there are other measures over which there is little controversy – but, consequently, less publicity (EHJ 2023;44:3948). We should ensure that all our high-risk (and our lower-risk) patients and their carers are aware of the importance of:

• Twice-daily tooth cleaning, and professional dental cleaning and follow-up at least twice yearly for high-risk (yearly for lower-risk) patients.
• Strict skin hygiene, including optimised treatment of chronic skin conditions.
• Disinfection of wounds.
• Curative antibiotics for any focus of bacterial infection.
• Avoiding self-medication with antibiotics.
• Strict infection control measures for any at-risk procedure.
• Avoidance of piercing and tattooing.
• When possible, limitation of infusion catheters and invasive procedures.
• Strict adherence to care for central and peripheral cannulae.

• There is increasing evidence of an association between invasive dental procedures and development of infective endocarditis in high-risk patients, and of a reduction in risk with antibiotic prophylaxis.
• Current dental guidelines from the Scottish Dental Clinical Effectiveness Programme recommend use of antibiotic prophylaxis along the lines recommended by the European Society of Cardiology (SDCEP, 2026, EHJ 2023;44:3948). 
• NICE guidance currently differs from the European guidelines, but DOES signpost to SDCEP (NICE 2008 (updated 2016), CG64).

So, in primary care:

• Discuss the importance of non-prescription preventive measures with patients, in particular good oral hygiene.
• Remember the risks associated with non-medical procedures such as tattooing and body piercing.
• Do not be surprised if patients at high risk are prescribed antibiotic prophylaxis by their dentist. It is generally the dentist's responsibility to prescribe for planned at-risk dental procedures, and they are being encouraged to do so.
• Be prepared to discuss the NICE and ESC guidelines with patients who may be at risk, and help them come to a shared decision about whether antibiotic prophylaxis is for them.
• Ensure patients are aware of the symptoms that may indicate infective endocarditis, and when, and how, to seek expert advice.
• Consider infective endocarditis in unwell, at-risk patients, and arrange same-day admission if you suspect it.

Although this has nothing to do with endocarditis, we are often asked this question so will include the answer here.

• Those with prosthetic joints do not require antibiotic prophylaxis for dental procedures (BNF 2017).

Endocarditis prophylaxis NICE suggests no one should routinely be offered antibiotic prophylaxis for endocarditis, but the guidance is over a decade old, and new European guidelines disagree. NICE also signposts to UK dental guidelines produced by SDCEP. UK dental guidelines advise dentists to prescribe antibiotic prophylaxis to patients with high-risk features undergoing certain dental procedures. ALL patients with mechanical or tissue surgical replacement heart valves are at high risk of endocarditis. For transcatheter valve replacements, aortic and pulmonary are high risk; mitral and tricuspid may also be. Patients should be made aware of non-drug measures which may reduce their risk. Educate patients on the symptoms of infective endocarditis and when, and how, to seek help.