von Reyn, Duke, and Modified Duke Classification*

von Reyn classification
 DefiniteDirect evidence of IE based on histology or bacteriology of vegetation or peripheral embolus
 Probable≥2 positive BCs plus one of the following:
 New regurgitation murmur
 Acquired or congenital heart disease
≤2 or negative BC, plus fever, new regurgitation murmur, and vascular phenomena
 Possible≥2 positive BCs plus one of the following:
 Acquired or congenital heart disease
 Vascular phenomena
≤2 or negative BC plus fever, acquired or congenital heart disease, and vascular phenomena
For Viridans streptococci IE only: ≥2 positive BCs without an extracardiac origin and fever
 RejectedIE unlikely, alternate diagnosis
IE likely, empiric antibiotic therapy warranted
Culture-negative IE diagnosed clinically
Duke and modified Duke classifications
 DefinitePathologic criteria:
 Microorganism demonstrated by culture or histologic examination of  vegetation, emboli, intracardiac abcess; or
 Active endocardial lesions on pathology examination
Clinical criteria:
 2 major criteria; or
 1 major criterion and 3 minor criteria; or
 5 minor criteria
 Possible1 major criterion and 1 minor criterion; or
3 minor criterion
 RejectedAlternate diagnosis; or
Resolution of IE syndrome after ≤4 days of antibiotherapy; or
No pathologic evidence of IE after ≥4 days of antibiotherapy; or
Does not meet criteria for possible IE.
  • * Adapted from von Reyn et al,1 Durack et al,4 and Li et al.8