Infective Endocarditis

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Infective Endocarditis

• What the Internist
• Needs to Know
• 2/09

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Pathogenesis

• Predosposing valve or endocardial lesion
• Platelet /fibrin sterile vegetation
• Bacteremia
• Seeding of vegetation/Platelet aggregation
• Platelet fibrin complex allows protected
  bacterial growth-high colony counts-low metabolic
  activity/protected from phagocytosis

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Mitral Valve Vegetation

• Vegetations form on low pressure downstream side
  of obstructing lesion

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Predisposing Conditions

• Prosthetic valve
• Calcific aortic stenosis/mitral insufficiency
• CHD bicuspid aortic valve, MVP, VSD
• Rheumatic heart disease
• IVDA-adulterant injury to TV
• Central catheters in HCA-IE
• Prior IE

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Bacterial Factors

• Produce sticky dextran substances
• S. viridansmutans, sanguis, mitior, salivarias
• S. bovis-50 large bowel lesion
• Enterococci- S. faecalis, S. faecium
• HACEK group-gram neg GI flora
• Group B strep diabetics, cancer, alcoholics
• Abiotrphia-old NVS, need B6 for growth

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Bacterial Factors-2

• Staph. aureus both abnormal normal valves,
  major cause of IVDA, and HCA-IE
• Gram negative aerobic uncommon cause of IE,
  except early PVE focal outbreaks of IVDA

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Clinical Manifestations-1Native Valves

• Systemic fever, chills, fatigue, anorexia,
  weight loss, arthralgias, low back pain,
  manifestations of inflammatory mediators
• Cardiac new or increased reguritant murmurs,
  CHF-edema, DOE, PND, fatigue, heart block-syncope

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Clinical Manifestations-2

• Embolic lungs-septic emboli, brain-stroke
  syndrome, kidney-pain hematuria, heart-MI,
  peripheral small arteriioles-Janeway lesion,
  mycotic aneursym-bleeding,

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Clinical Manifestations-3

• Immunologic Subacute presentations
• glomerulonephritis, Oslers nodes, Roth spots,
  Rheumatoid factor

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Clinical Exam IE

• VS temp, pulse rate, BP-pulse pressure
• Skin/MM petechiae- conjunctiva, nailbeds,
• Fundus Roth spots, flame hemorrhages
• Cardiac AI, MR, TR
• ABD LUQ tenderness
• Ext Osler nodes, Janeway, decreased perfusion

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Diagnosis Duke Criteria

• Clinical Endocarditis Definite
• 2 major
• 1 major 3 minor
• 5 minor
• Possible
• 1 major 1 minor
• 3 minor

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Duke Criteria Major

• I Blood Cultures
• 2 cultures of typical organisms
• 3 or a majority of gt of 4, drawn gt 1 hour apart
• II Echocardiogram
• -oscillating mass on valve or supporting
  structures, path of regurgitant jet
• - endocardial abscess
• - new dehiscence of PV, new regurgitation

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Duke Criteria-Minor

• Temp gt 38.0 C (100.4)
• Vascular emboli, mycotic aneurysm, Janeway
  lesions, conjunctival hemorrhages
• Immune Roth, Osler, GMN, RF
• Micro blood culture, does not meet maj.
• Echo suspicious, does not meet major
• Predisposing condition or IVDA

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Therapy General Principles

• Isolation of the causative organism is key, and
  may dictate in certain situations withholding
  antibiotics until blood cultures positive.
• Cidal therapy should be used.
• Antibiotic choices guided by MIC values and when
  appropriate synergy testing.
• Duration is usually 4-6 weeks
• Surgical therapy increasingly utilized.

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Therapy Antibiotics

• Strep. viridans, bovis, MIC lt 0.1 mcg/ml
• Pen G 18M/day or Ceftriaxone 2 gram 4 wks
• or 2 wks gentamicin 3mg/kg q24h
• Strep. MIC gt 0.1 to lt 0.5 mcg/ml
• PenG/Ceftri 4 wks Gentamicin 2 wks
• Strep/Enetrococci MIC gt 0.5 mcg/ml
• PenG/Ampi Gentamicin 4-6 wks

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Therapy-Antibiotics

• Enterococci Synergy testing, Genta/Strep
• Enterococci PCN/Ampi R, Vanco R
• MSSA Nafcillin/Oxacillin 2 g q4h 4-6 wks,some
  add 3 days gentamicin if toxic
• MRSAVanco if MIC lt 1.0, trough 15-20
• MRSA Vanco gt 1.0, Daptomycin Genta
• HACEK Ceftriaxone 2 grm q24h for 4 wks

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Prosthetic Valve Endocarditis

• Staph. epidermidis Vancomycin, Rifampin 300mg
  TID X 6 weeks gentamicin 3mg/kg for 2 wks
• MRSA same as above
• MSSA substitute nafcillin 2 g q4h for vanco
• Surgical therapy often necessary

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Surgical IndicationsEvidence/Consensus

• Acute AI or MR with heart failure
• Acute AR with MV preclosure
• Fungal/Resistant organism
• Aortic root abscess, aortic aneurysm
• Persistent bacteremia after 7-10 days of
  appropriate antibiotic therapy, no non-cardiac
  etiology, usually vegetation gt 10 mm. Or
  myocardial abscess

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Surgical Therapy/Conflicting Evidence

• Recurrent emboli after antibiotic RX
• Mobile vegetations gt 10 mm

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Prophylaxis of IE

• What is the risk? CID 2006 42 10207
• France Predisposing condition/invasive dental
  procedure-observational pop.
• Prosthetic valve 1/11,000
• Native valves (NV) 1/54,000
• NV prophylaxis 1/150,000
• NNT 75,000

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Prophylaxis Changes in AHA Guidelines 2007

• Only for those at highest risk
• PV
• Prior IE
• Heart transplant with valvulopathy
• Cyanotic CHD palliative shunts, repaired with
  prosthetic material for first six months,
  repaired with residual defects

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Updated Prophylaxis

• Only for high risk procedures
• Dental with gingival tissue and/or periapical
• Respiratory tract with mucosal incision
• GI/GU with ongoing infection
• Procedures on infected SST

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Prophylaxis Antibiotics

• Dental/Resp
• Amoxicillin 2 grams 30-60 min before
• Cephalexin 2 grams
• Clindamycin 600 mg
• Vancomycin 1 gram over 1 hour 1 ½-2 hrs before
  procedure

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Questions

• You are referred three patients in your clinic to
  suggest IE prophylaxis before procedures.
• Pt.1. 24 YO woman with MR prolapse moderate
  regurgitation. Elective C-section.
• Pt. 2. 56 YO man with moderate AS due to bicuspid
  valve, extensive gum surgery.

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• Pt. 3. History of bioprosthetic AV, undergoing
  TURP with chronic prostatic infection with
  Enterococci faecalis.

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Questions

• A 46 YO Korean nurse is admitted with a 24 hour
  history of abrupt aphasia and mild right sided
  weakness.An MRI shows left temporal restricted
  diffusion, and multilpe similar smaller areas
  suggestive of emboli. She denies significant PMH
  except being told she had a heart murmur when she
  gave birth 20 years prior. In addition, over the
  past 6 weeks she has had intermittent fever and
  arthralgia for which she self-medicated with
  levofloxacin.
• Exam T 99, P 94, BP118/70
• Slight expressive aphasia-improving
• Conjunctival hemorrhage L eye
• III/VI diastolic rumble apical area/lungs clear

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• Mild right pronator drift
• Blood cultures negative X 3 from admission
• Echo very thickened calcified stenotic mitral
  valve consistent with RHD, cannot rule out
  vegetation
• Rheumatoid factor negative

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• Does this patient meet Duke Criteria for IE?
• What would be your diagnostic and therapeutic
  approach?
• Should you follow the neurologists
  recommendation to start anticoagulation?

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