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Infective Endocarditis

Checked: 08-08-2025 by Rob Adams Next Review: 08-08-2027

Overview

Infective endocarditis (IE) is a rare, life-threatening disease that has long-lasting effects even among patients who survive and are cured. It disproportionately affects those with underlying structural heart disease and is increasingly associated with patients who have intravascular prosthetic material. Once established, infective endocarditis can involve almost any organ system in the body (1).

Risk Factors

Cardiac-related

Prosthetic heart valves
Congenital heart disease (especially unrepaired or partially repaired defects)
Previous history of IE
Rheumatic heart disease
Mitral valve prolapse with regurgitation

Other Risk Factors

Intravenous drug use
Long-term indwelling venous catheters
Immunosuppression
Recent dental or surgical procedures
Poor dentition/oral hygiene

Clinical Presentation

IE has a variable and often insidious onset.

General Symptoms include: Fever, fatigue, malaise, night sweats, weight loss
Cardiac Signs: New or changing heart murmur, signs of heart failure
Other manifestations: Petechiae (especially conjunctival or on palate), splinter haemorrhages (nails), embolic phenomena (e.g., stroke, limb ischemia, renal infarction), Janeway lesions (painless erythematous macules on palms/soles), Osler nodes (tender nodules on fingers/toes), Roth spots (retinal haemorrhages with pale centres)

Red Flags

Emergency (999) or admission via Medical Assessment/Admission and Weekday IUC Professional Line same day referral (BNSSG) should be made for patients with:

Suspected IE with systemic signs of septicaemia.
New murmur with fever
Signs of embolic events or stroke
Congenital heart disease and fever (>38oC) for more than 3 days and no obvious source of infection*

Investigations in Primary Care

Do not delay referral for tests if IE is suspected (see Red Flags above).

Investigations in primary care may raise suspicion of IE include:

FBC - neutrophilia
CRP – typically raised
U&E, LFTs – may reveal secondary organ involvement
Urinalysis – microscopic haematuria
ECG – may show conduction abnormalities in advanced cases

Do not start antibiotics in primary care if IE is suspected.

Antibiotic prophylaxis

See NICE CG64 (2) for full guidance.

In summary:

Antibiotic prophylaxis against infective endocarditis is not recommended routinely in patients having most dental and non-dental procedures.
However, patients in at risk groups should be aware of the risks and take precautions as detailed below.
Any episodes of infection in people at risk of infective endocarditis should be investigated and treated promptly to reduce the risk of endocarditis developing.

At Risk Groups

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 non‑medical procedures such as body piercing or tattooing.

Resources

(1) Infective Endocarditis: Symptoms and Treatment

(2) Prophylaxis against infective endocarditis: antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures | NICE

Efforts are made to ensure the accuracy and agreement of these guidelines, including any content uploaded, referred to or linked to from the system. However, BNSSG ICB cannot guarantee this. This guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer, in accordance with the mental capacity act, and informed by the summary of product characteristics of any drugs they are considering. Practitioners are required to perform their duties in accordance with the law and their regulators and nothing in this guidance should be interpreted in a way that would be inconsistent with compliance with those duties.

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