From the Guidelines
The Duke criteria are a set of diagnostic guidelines used to identify infective endocarditis based on clinical, microbiological, and echocardiographic findings, classifying patients into definite, possible, or rejected categories of endocarditis diagnosis, as outlined in the most recent guidelines 1. The major criteria include positive blood cultures for typical endocarditis organisms and evidence of endocardial involvement on echocardiography (such as an oscillating intracardiac mass, abscess, new valvular regurgitation, or prosthetic valve dehiscence) 1. Minor criteria encompass:
- Predisposing heart conditions
- Fever above 38°C
- Vascular phenomena (like arterial emboli or septic pulmonary infarcts)
- Immunologic phenomena (such as glomerulonephritis or Osler's nodes)
- Positive blood cultures not meeting major criteria A definite diagnosis requires either two major criteria, one major plus three minor criteria, or five minor criteria, as stated in the modified Duke criteria 1. Possible endocarditis is diagnosed with one major plus one minor criterion or three minor criteria. The Duke criteria are valuable because they standardize the diagnostic approach to endocarditis, allowing for earlier treatment decisions in a condition where delayed therapy significantly increases mortality, as noted in the guidelines 1. However, clinical judgment remains essential, particularly in culture-negative cases or when echocardiographic findings are equivocal, highlighting the importance of considering the most recent and highest quality studies, such as 1, when making diagnostic decisions.
From the Research
Definition of the Duke Criteria
The Duke criteria are a set of guidelines used for the diagnosis of infective endocarditis (IE) 2, 3, 4. They were introduced to improve the diagnosis and management of IE, which can be challenging due to its non-specific presentation.
Components of the Duke Criteria
The Duke criteria consist of major and minor criteria:
- Major criteria:
- Positive blood culture for IE
- Evidence of endocardial involvement (e.g., echocardiography)
- Minor criteria:
- Predisposition (e.g., heart condition)
- Fever
- Vascular phenomena (e.g., emboli)
- Immunological phenomena (e.g., glomerulonephritis)
- Microbiological evidence (e.g., positive blood culture but not meeting major criterion)
Application of the Duke Criteria
The Duke criteria are used to categorize patients into three groups:
- Definite IE: meeting two major criteria or one major and two minor criteria
- Possible IE: meeting one major and one minor criterion or three minor criteria
- Rejected IE: not meeting the above criteria 2, 3, 4
Evaluation of the Duke Criteria
Studies have evaluated the performance of the Duke criteria, showing that they are specific for ruling out IE in patients with acute fever or fever of unknown origin 3. The criteria have undergone revisions, with the 2023 European Society of Cardiology version showing improved sensitivity compared to the 2015 version 4. However, the diagnosis of IE remains challenging, and the Duke criteria should be used in conjunction with clinical judgment and other diagnostic tools 2, 5, 6.