Infective endocarditis – 8/6/18

Thanks to Janhavi for presenting the case of a middle-aged man with no significant PMH presenting with acute onset of malaise, myalgias, and a “stubbed toe,” septic with petechiae on palms and soles, found to have mitral valve endocarditis.


Clinical Pearls:

  • Endocarditis is more common in men (2:1)
  • ~50% of cases of endocarditis occur in people with no known underlying valve disease
  • 80% of cases are caused by staph and strep species
  • TEE is the gold standard for diagnosis and recommended when clinical suspicion for endocarditis is high.  TTE is more helpful to rule out disease when clinical suspicion is low.
  • Indications for early surgery based on this NEJM article include:
    • Heart failure
    • Uncontrolled infection
    • Prevention of embolic events

Duke’s criteria:

Major criteria:

  • Blood culture positive:
    • Typical organism in two separate blood cultures
    • Persistently positive blood cultures
    • Single positive culture for Coxiella
  • E/o endocardial involvement
    • Echo positive for vegetation
    • New valve regurgitation

Minor criteria:

  • Predisposition to IE (i.e. IVDU, prosthetic valve, congenital cyanotic heart disease)
  • Fever >38
  • Vascular phenomena ⇒ arterial emboli, pulmonary infarcts, mycotic aneurysms, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesions
  • Immunologic phenomena ⇒ GN, Osler’s nodes, Roth’s spots, RF
  • Microbiologic evidence: positive blood culture not meeting major criteria

Probability of endocarditis:

Definite IE:

  • 2 major, 1 major + 3 minor, 5 minor

Possible IE:

  • 1 major + 1 minor, or 3 minor

Rejected IE:

  • Firmly established alternative diagnosis
  • Resolution of symptoms < 4 days with antibiotics
  • Does not meet definite/possible criteria

Indications for surgery:

  • Valve dysfunction causing heart failure
  • Perivalvular extension with development of abscess, fistula, and/or heart block
  • Fungi or other highly resistant organisms that are difficult to treat with abx alone
  • Persistent bacteremia despite maximal treatment
  • Recurrent embolization with persistent vegetations
  • Large vegetations (>1 cm) with severe valvular regurg
  • S aureus prosthetic valve endocarditis

Indications for early surgery:

  • Heart failure
  • Uncontrolled infection
  • Prevention of embolic events

Complications:

  • Most common cause of death: heart failure
  • Heart block
  • Emboli
    • More likely with s. aureus or S. bovis, veg > 1 cm, or increased veg mobility on echo
    • Antiplatelet therapy initiation is not recommended because of increased risk of hemorrhagic conversion of septic emboli

Want more?

  • Check out this blog post and this great review article in the NEJM.

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