The presence of an Endocarditis Team is crucial in IE. This multidisciplinary approach has been shown to significantly reduce the 1-year mortality in infective endocarditis. Do not start antibiotics before taking multiple blood cultures (at least 3 over a period of 12 hrs) with excellent asepsis.
- Infection of the Heart valve (native or prosthetic), Endocardium or blood vessel, Congenital anomaly VSD, Aortic valve.
- There is a site of pre-existing endocardial damage due to jets and turbulence from MR/VSD which is vulnerable to infection.
- The infection causes vegetations, composed of organisms, fibrin and platelets, grow and may break away as emboli.
- There is local tissue destruction. Abscesses form and valves fail to function with regurgitation.
- Immune response can lead to vasculitis and skin lesions, immune complex deposition. Emboli can occur to the brain and other organs.
High risk groups
- Patients with a prosthetic valve or with prosthetic material used for cardiac valve repair. Higher risk of IE, a higher mortality and morbidity than patients with native valves and an identical pathogen. Also applies to transcatheter-implanted prostheses and homografts.
- Patients with previous IE have a greater risk of new IE, higher mortality and higher incidence of complications than patients with a first episode of IE
- Patients with untreated cyanotic congenital heart disease (CHD) and those with CHD who have postoperative palliative shunts, conduits or other prostheses. Recommend prophylaxis for the first 6 months after the procedure until endothelialisation of the prosthetic material has occurred.
Vegetations on Mitral valve
- Malaise, weight loss, fever, new murmurs, AF, aching joints
- New stroke or embolic episode e.g strokes
- Roth spots in fundi, Clubbing
- Splinter haemorrhages in nails
- Janeway lesions
- Pulmonary oedema, rotten teeth/gums
- Positive histology or microbiology of pathological material obtained at autopsy or cardiac surgery (valve tissue, vegetations, embolic fragments, or intracardiac abscess content)
- Two positive blood cultures showing typical organisms consistent with infective endocarditis, such as Streptococcus viridans and the HACEK group OR
- Persistent bacteraemia from two blood cultures taken > 12 hours apart or three or more positive blood cultures where the pathogen is less specific, such as Staphylococcus aureus and Staph epidermidis OR
- Positive serology for Coxiella burnetii, Bartonella species, or Chlamydia psittaci OR
- Positive molecular assays for specific gene targets
- Positive echocardiogram showing oscillating structures, abscess formation, new valvular regurgitation, or dehiscence of prosthetic valves
- Predisposing heart disease
- Fever > 38°C
- Immune phenomena e.g. glomerulonephritis, Osler's nodes, Roth spots, +ve RF
- Microbiological evidence not fitting major criteria
- Elevated C reactive protein or erythrocyte sedimentation rate
- Vascular phenomena e.g major emboli, splenomegaly, clubbing, splinter haemorrhages, petechiae, purpura
Definite infective endocarditis
- Pathological criteria positive OR
- Two major criteria OR
- One major and two minor criteria OR
- Five minor criteria
- Strep viridans: subacute, oral/resp
- Enterococci: subacute, Gut/Urinary
- Staph. Aureus: Severe acute infection. IV Drug users
- Staph. Epidermidis: Skin, Post cardiac op
- Gram-negative HACEK group (Haemophilus spp., Actinobacillus, Cardiobacterium hominis, Eikenella spp. Kingella kingae).
- Coxiella burnetii (Q fever) |Brucella : from animals
- Yeasts/fungi: immunocompromised
- FBC: normochromic, normocytic anaemia. Raised WCC. Raised ESR and CRP: U&E: Usually normal
- Urinalysis: Microscopic haematuria
- Blood cultures: crucial. Send 3 sets over a few hours before antibiotics. Cultures guide treatment. Starting antibiotics is a senior decision.
- Echocardiography: defines valve status and detects abscess. Transoesophageal is best.
- ECG: Sinus tachy, AF, AV block (aortic root abscess)
- CXR: evidence of cardiac failure
- CT/MRI head if new neurology: Embolic infarcts which often bleed if anticoagulated.
Mitral valve vegetation see on TOE/TEE
Management: Diagnose as above
- Medical: Remove infection source e.g. dental/skin abscess. Choice of antibiotic will be based on blood cultures which must be sent off early and before antibiotics started. There must be multiple from multiple sites and done with strict asepsis. Drug treatment of Prosthetic Valve Endocarditis should last longer (at least 6 weeks) than that of Native valve endocarditis (NVE) (2-6 weeks)
- Acute (S.Aureus): Flucloxacillin + Gentamicin.
- Subacute (Strep Viridans): BenzylPenicillin + Gentamicin. Use culture results and expert opinion for others.
- Surgery if valve failure or abscess formation, failed medical treatment or large vegetations on left-sided heart valves (high risk of systemic emboli). Also: Caution with anticoagulants. Surgical treatment is used in approximately half of the patients with IE because of severe complications. Early consultation with a cardiac surgeon is recommended in order to determine the best therapeutic approach. Identification of patients requiring early surgery is frequently difficult and is an important scope of the Heart Team. In some cases, surgery needs to be performed on an emergency basis (within 24 h), urgent basis (within a few days, <7 days), irrespective of the duration of antibiotic treatment. In other cases, surgery can be postponed to allow 1 or 2 weeks of antibiotic treatment under careful clinical and echocardiographic observation before an elective surgical procedure is performed. The three main indications for early surgery in IE are its 3 main complications, i.e. HF, uncontrolled infection, and prevention of embolic events.
- Prosthetic valve endocarditis needs referal to regional Cardiothoracic surgical centre.
- Haemodynamic deterioration might precipitate the need for surgery in endocarditis. Operative risk is balanced with better prognosis if infection is treated first.
- Endocarditis may need surgical intervention. Involve Cardiologists as early as possible.
- Transthoracic echocardiography may need to be supplemented by TOE|TEE will often help
- Rarely Antibiotic sensitivity can cause a mild fever and lead to a false suspicion that the endocarditis is not successfully treated: always liaise closely with the microbiologist.
- Escalate cases that are either not responding or worsening with the surgeons, via the Cardiologist.
- Right-sided endocarditis is a disease that is characteristic of IV drug users. There is a murmur and signs of TR and lung consolidation.