Elena ShevchenkoSeptember 29, 2021

Infective endocarditis (IE) is defined as an infection of the endocardial surfaces of the heart—primarily of 1 or more heart valves, the mural endocardium, or a septal defect. Its intracardiac effects include severe valvular insufficiency, intractable congestive heart failure, and myocardial abscesses. If left untreated, IE is inevitably fatal.
Risk factors for infective endocarditis | |
High risk | Prosthetic valves Previous bacterial endocarditis Aortic valve disease Mitral regurgitation or mixed mitral disease Cyanotic congenital heart disease Patient ductus arteriosis Uncorrected left → right shunt (Video) Infective Endocarditis: Modified Duke Criteria Intracardiac or systemic pulmonary shunts |
Moderate risk | Mitral valve prolapse with regurgitation or valve thickening Isolated mitral stenosis Tricuspid valve disease Pulmonary stenosis See Also Teaching About Real-World, Transdisciplinary Problems and Phenomena through Convergence EducationCustomer Testimonials: How To Use Them + Examples (2022)14 best facial sunscreens for different skin typesPhenomenal conservatism: It seems like suffering is gratuitousHypertrophic cardiomyopathy
Degenerative valve disease in elderly Mitral thrombus (e.g. post infarction) |
Low risk | Mitral valve prolapse without regurgitation Tricuspid incompetence without structural abnormality Isolated atrial septal defect Surgically corrected left → right shunt with no residual shunt Calcification of mitral valve annulus Ischemic heart disease and/or previous coronary artery bypass graft (CABG) Permanent pacemaker Atrial myxoma |
Other predisposing factors: · Arterial prosthesis or arteriovenous fistulae · Recurrent bacteremia (Video) Clinician's Corner: Endocarditis (e. g. IV drug users, severe periodontal disease, colon carcinoma) · Conditions predisposing to infections (e.g. diabetes, renal failure, alcoholism, immunosuppression) · Recent central line In many cases no obvious risk factor is identified! |
Diagnosis of endocarditis
Key facts!
- Clinical features can be non-specific and diagnosis difficult.
- Maintain a high index of suspicion in patients presenting with unexplained fever, a predisposing cardiac lesion, bacteremia, and embolic phenomena.
Duke classification
- Developed in 1994 and modified in 2000 as a means of standardizing the diagnosis of IE.
- This classification has a sensitivity of approximately 80% overall when the criteria are evaluated at the end of patient follow-up in epidemiological studies.
- However, the modified Duke criteria show a lower diagnostic accuracy for early diagnosis in clinical practice, especially in the case of prosthetic valve endocarditis (PVE) and pacemaker or defibrillator lead IE.
- Cardiac/whole-body computer tomography (CT) scan, cerebral MRI, 18F-FDG PET/CT, and radiolabeled leukocyte SPECT/CT might improve the detection of silent vascular phenomena as well as endocardial lesions.
- The addition of the results of these imaging modalities may improve the sensitivity of the modified Duke criteria in difficult cases.
Definitions of the terms used in the European Society of Cardiology 2015 modified criteria for the diagnosis of infective endocarditis
Major criteria |
I. Blood cultures positive for IE a. Typical microorganisms consistent with IE from 2 separate blood cultures: • Viridans streptococci, Streptococcus gallolyticus (Streptococcus bovis), Staphylococcus aureus; or • Community-acquired enterococci, in the absence of a primary focus; or b. Microorganisms consistent with IE from persistently positive blood cultures: • ≥2 positive blood cultures of blood samples drawn >12 h apart; or • All of 3 or a majority of ≥4 separate cultures of blood (with and last samples drawn ≥1 h apart); or • Single positive blood culture for Coxiella burnetii or phase I IgG antibody titer >1:800. |
II. Imaging positive for IE a. Echocardiogram positive for IE: • Vegetation • Abscess, pseudoaneurysm, intracardiac • Valvular perforation or aneurysm • New partial dehiscence of prosthetic valve. b. Abnormal activity around the site of prosthetic valve implantation detected by 18F-FDG PET/CT (only if the prosthesis was implanted for >3 months) or radiolabeled leukocytes SPECT/CT. c. Define paravalvular lesions by cardiac CT. |
Minor criteria |
1. Predisposition such as predisposing heart condition, or injection drug use. 2. Fever as temperature >38°C. 3. Vascular phenomena (including those detected by imaging only): major arterial emboli, septic pulmonary infarcts, infectious (mycotic) aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway’s lesions. 4. Immunological phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor. 5. Microbiological evidence: positive blood culture but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with IE. |
Definition of infective endocarditis according to the modified Duke criteria (adapted from Li et al.)
Definite IE |
Pathological criteria: • Microorganisms demonstrated by culture or on histological examination of a vegetation, a vegetation that has embolized, or an intracardiac abscess specimen; or • Pathological lesions; vegetation or intracardiac abscess by histological examination showing active endocarditis| Clinical criteria: • 2 major criteria; or • 1 major criterion and 3 minor criteria; or • 5 minor criteria |
Possible IE |
• 1 major criterion and 1 minor criterion; or • 3 minor criteria |
Rejected IE |
• Firm alternate diagnosis; or| • Resolution of symptoms suggesting IE with antibiotic therapy for ≤4 days; or • No pathological evidence of IE at surgery or autopsy, with antibiotic therapy for ≤4 days; or • Does not meet criteria for possible IE, as above |
*The identification of paravalvular lesions by cardiac CT should be considered a major criterion. *In the setting of the suspicion of endocarditis on a prosthetic valve, abnormal activity around the site of implantation detected by 18F-FDG PET/CT (only if the prosthesis was implanted for 3 months) or radiolabeled leucocyte SPECT/ CT should be considered a major criterion. *The identification of recent embolic events or infectious aneurysms by imaging only (silent events) should be considered a minor criterion. |
Investigation of endocarditis
Blood cultures | Take 3-4 sets of culture from different sites at least an hour apart and inoculate a minimum of 10mL/bottle for the optimal pick-up rate. Both aerobic and anaerobic bottles must be used. Lab should be advised that IE is a possibility, especially if unusual organism is suspected. In stable patients on antibiotic therapy, doses must be delayed allowing culture on successive days. Ask for prolonged (fungal) culture in IV drugs users. When a microorganism has been identified, blood cultures should be repeated after 48–72 h to check the effectiveness of treatment. |
Full blood count | May show normochromic, normocytic anemia (exclude hematinic deficiency), neutrophil leukocytosis, and perhaps thrombocytopenia. |
Urea and electrolytes | May be deranged (this should be monitored throughout treatment). |
Liver function tests | May be deranged, especially with an increase in alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT). |
Erythrocyte sedimentation rate /C-reactive protein/ procalcitonin | Acute phase reaction and sepsis indicator |
Urinalysis | Microscopic hematuria ± proteinuria |
Immunology | Polyclonal elevation in serum Igs, complement levels |
Electrocardiogram | May have changes associated with any underlying cause. There may be atrioventricular block or conduction defects (especially aortic root absence) and, rarely (embolic), acute myocardial infarction. |
Chest X-ray | May be normal. Look for pulmonary oedema or multiple infected or infarcted areas from septic emboli (tricuspid endocarditis). |
Echocardiography (ECHO) | Transthoracic ECHO may confirm the presence of valve lesions and/or demonstrate vegetations if .2 mm in size. Transesophageal echocardiography is more sensitive for aortic root abscess and mitral leaflet involvement. A normal ECHO does not exclude the diagnosis. If the suspicion for IE remains high despite negative TEE findings, a repeat TEE should be performed after 3 to 5 days. Furthermore, repeat TEE should be performed if a new intracardiac complication is suggested by clinical features. Performance of TTE is also reasonable upon completion of antibiotic therapy for the establishment of a new baseline. Three echocardiographic findings are major criteria in the diagnosis of IE: vegetation, abscess or pseudoaneurysm and new dehiscence of a prosthetic valve. |
Magnetic resonance imaging | Useful in investigation of paravalvular extension, aortic root aneurysm and fistulas. Systematic cerebral MRI has an impact on the diagnosis of IE since it adds one minor Duke criterion. |
Nuclear imaging | With the introduction of hybrid equipment for both conventional nuclear medicine [e.g. single-photon emission CT (SPECT)/CT] and PET (i.e. PET/CT), nuclear molecular techniques are evolving as an important supplementary method for patients with suspected IE and diagnostic difficulties. Radiolabeled WBC SPECT/CT is more specific for the detection of IE and infectious foci than 18F-FDG PET/CT and should be preferred in all situations that require enhanced specificity. |
Dentition | All patients should have an orthopantomogram – a panoramic dental X-ray and a dental opinion. |
Swabs | Any potential sites of infection (skin lesion). |
Ventilation/perfusion (V/Q) scan | In cases when right-sided endocarditis is suspected, this may show multiple mismatched defects. |
Histological diagnosis of infective endocarditis | Pathological examination of resected valvular tissue or embolic fragments remains the gold standard for the diagnosis of IE. |
Save serum for | Aspergillus precipitins; Candida antibodies (rise in titer); Q fever (Coxiella burnetti) compliment fixation test; Chlamydia complement fixation test; Brucella agglutinins; Legionella antibodies; Bartonella species. |
Literature:
- Durack DT, Lukes AS, Bright DK. New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service.American Journal of Medicine. 96(3):200-9, 1994.
- Li JS, Sexton DJ, Mick N, Nettles R, Fowler VG Jr, Ryan T, Bashore T, Corey GR. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis. 2000 Apr;30(4):633-8. doi: 10.1086/313753. Epub 2000 Apr 3. PMID: 10770721.
- Yehuda Adler, Philippe Charron, Massimo Imazio, Luigi Badano, Gonzalo Barón-Esquivias, Jan Bogaert, Antonio Brucato, Pascal Gueret, Karin Klingel, Christos Lionis, Bernhard Maisch, Bongani Mayosi, Alain Pavie, Arsen D Ristić, Manel Sabaté Tenas, Petar Seferovic, Karl Swedberg, Witold Tomkowski, ESC Scientific Document Group, 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC) Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS), European Heart Journal, Volume 36, Issue 42, 7 November 2015, Pages 2921–2964, https://doi.org/10.1093/eurheartj/ehv318
- Thornhill MH, Gibson TB, Cutler E, Dayer MJ, Chu VH, Lockhart PB, et al. Antibiotic Prophylaxis and Incidence of Endocarditis Before and After the 2007 AHA Recommendations. J Am Coll Cardiol. 2018 Nov 13. 72 (20):2443-2454.[Medline].
- https://emedicine.medscape.com/article/216650-guidelines
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Categories: Anesthesiology, Cardiology, Cardiology, Diagnostic criteria, Endocarditis, Sepsis
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FAQs
Infective endocarditis. Diagnostic criteria for IE| ClinCaseQuest? ›
Persistently positive blood culture, defined as recovery of a microorganism consistent with infective endocarditis from: blood cultures drawn more than 12 h apart, or. all of three or a majority of four or more separate blood cultures, with first and last drawn at least 1 h apart.
What is the gold standard for diagnosing infective endocarditis? ›Histological/immunological techniques. Histological findings are included in the Duke and von Reyn diagnostic criteria and pathological examination of resected valvar tissue or embolic fragments remains the gold standard for the diagnosis of infective endocarditis.
What is the Duke criteria for endocarditis? ›Microorganism consistent with IE from persitently positive blood cultures, defined as follows: At least 2 positive cultures of blood samples drawn >12 h apart; or. All of 3 or a majority of ≥4 separate cultures of blood (with first and last sample drawn at least 1h apart)
What is IE diagnosis? ›The diagnosis of IE is based on the modified Duke Criteria for Infective Endocarditis: the association of clinical signs (such as fever and presence of murmur in patients with risk of heart disease), positive blood culture for frequent etiological agents and typical echocardiographic findings (vegetation, periannular ...
Which of the following is considered a major criteria in the diagnosis of IE? ›Major criteria
persistently positive blood cultures, defined as recovery of a microorganism consistent with infective endocarditis from: 2 blood cultures drawn 12 hours apart or all of 3 or most of 4 or more separate blood cultures, with first and last drawn at least one hour apart.
Blood tests may be used to help diagnose endocarditis or identify the most effective treatment. Blood tests may include: a blood culture test to check for a specific bacteria or fungi. an erythrocyte sedimentation rate (ESR) test.
Why does endocarditis require 3 blood cultures? ›For diagnosing subacute IE, draw 3 to 5 sets of blood cultures over 24 hours. This helps detect 92-98% of cases in patients who have not recently received antibiotics. In the case of acute IE, 3 sets may be drawn over 30 minutes (with separate venipunctures) to help document a continuous bacteremia.
What is Duke's criteria used for? ›Formal criteria to diagnose and stratify patients suspected of having infective endocarditis (IE) into “definite”, “possible”, and “rejected”.
What are Osler nodes? ›Osler nodes and Janeway lesions are cutaneous manifestations of endocarditis, a disease most commonly arising from a bacterial or fungal infection of the cardiac endocardium.[1] Osler nodes are tender, purple-pink nodules with a pale center and an average diameter of 1 to 1.5 mm.[2] They are generally found on the ...
What is a Janeway? ›Janeway lesions are irregular, nontender hemorrhagic macules located on the palms, soles, thenar and hypothenar eminences of the hands, and plantar surfaces of the toes. They typically last for days to weeks. They are usually seen with the acute form of bacterial endocarditis.
How do you collect a blood sample for infective endocarditis? ›
endocarditis, obtain 3 blood cultures on the first day, spacing the venipunctures at least 30 minutes apart. If these are negative, obtain 2 more sets on subsequent days. venipuncture site first with 70% isopropyl alcohol, air dry, and then apply the main disinfectant.
What are Osler nodes? ›Osler nodes and Janeway lesions are cutaneous manifestations of endocarditis, a disease most commonly arising from a bacterial or fungal infection of the cardiac endocardium.[1] Osler nodes are tender, purple-pink nodules with a pale center and an average diameter of 1 to 1.5 mm.[2] They are generally found on the ...
What causes Osler nodes? ›Causes. Osler's nodes result from the deposition of immune complexes. The resulting inflammatory response leads to swelling, redness, and pain that characterize these lesions. The nodes are commonly indicative of subacute bacterial endocarditis.
What is a Janeway? ›Janeway lesions are irregular, nontender hemorrhagic macules located on the palms, soles, thenar and hypothenar eminences of the hands, and plantar surfaces of the toes. They typically last for days to weeks. They are usually seen with the acute form of bacterial endocarditis.