298.3 🏥 內科專科考前版

298.3.1 Mechanistic Deep Dive

298.3.1.1 Biofilm + Vegetation Formation

  • Adhesion proteins (clumping factor, fibronectin-binding)
  • Fibrin deposition
  • Platelet aggregation
  • Biofilm matrix protects from immune + antibiotics
  • Embolic potential

298.3.1.2 Why Surgery Often Needed

  • Antibiotic penetration limited in biofilm
  • Source control essential
  • Mechanical complications

298.3.2 Recent Trials & Updates

298.3.2.1 POET (2019)

  • Practice-changing
  • Stable patients with NVE switch to oral antibiotics after 10d IV
  • Reduced cost + complications

298.3.2.2 DAILY (2013) Ampicillin + Ceftriaxone for Enterococcus

  • Non-aminoglycoside option
  • Less nephrotoxicity
  • Equally effective in many cases

298.3.2.3 2023 ESC IE Guidelines

  • Updated Duke criteria
  • New imaging modalities (CT, PET) integrated
  • Earlier surgery emphasis
  • IE team approach

298.3.2.4 Endocarditis Team

  • Class I in 2023 ESC
  • Multidisciplinary: ID, cardiology, cardiac surgery, microbiology, radiology, nuclear medicine
  • Improves outcomes

298.3.2.5 Fastidious Organism Diagnostics

  • 16S rRNA PCR
  • Multiplex PCR panels
  • Mass spectroscopy
  • Improved culture-negative IE diagnosis

298.3.2.6 Oral Switch (POET) Practical

  • Stability + clinical improvement + 10 days IV
  • Targeted oral antibiotic per culture
  • Follow-up close
  • Outpatient OPAT alternative

298.3.3 High-Yield Specialist Points

298.3.3.1 Mycotic Aneurysm

  • Cerebral most common
  • 5% of IE
  • Risk of rupture
  • Screen with CTA in S. aureus IE with neurologic symptoms
  • Treat: antibiotics + endovascular coiling / surgery if growing

298.3.3.2 Embolic Stroke + IE Surgery Timing

  • Recent stroke (< 48 hr): risk of hemorrhagic conversion with cardiopulmonary bypass
  • Delay surgery 1-2 weeks if possible
  • Urgent surgery if mechanical complications outweigh delay risk

298.3.3.3 Glomerulonephritis in IE

  • Immune complex
  • Resolves with antibiotic treatment
  • AKI complicates management

298.3.3.4 Prosthetic Valve Considerations

  • Aortic > mitral
  • Early (< 12 mo) more virulent
  • Often need re-do surgery
  • See Ch298

298.3.3.6 Q Fever Endocarditis

  • Coxiella burnetii (ruminant exposure)
  • Culture-negative + prosthetic valve common
  • Doxycycline + hydroxychloroquine 18-24 months
  • Phase I IgG ≥ 1:800

298.3.3.7 Bartonella Endocarditis

  • Cat scratch (B. henselae)
  • Homeless / lice (B. quintana)
  • Diagnosis: serology, PCR, blood culture
  • Doxycycline + gentamicin or rifampin

298.3.3.8 Tropheryma whipplei

  • Rare
  • GI + neurologic + cardiac
  • Doxycycline + hydroxychloroquine

298.3.3.9 Marantic / Libman-Sacks Endocarditis

  • Non-infectious vegetations
  • Cancer, hypercoagulable, SLE/APS
  • Echo + cultures + workup
  • Treat underlying

298.3.3.10 Newer Antibiotic Options

  • Daptomycin alternative for S. aureus (non-pulmonary IE)
  • Ceftaroline: 5th-gen cephalosporin with MRSA coverage
  • Tedizolid, oritavancin: emerging
  • Long-acting agents for outpatient

298.3.4 Pearls

  • Modified Duke 2023: blood culture + imaging (echo, CT, PET) major criteria
  • S. aureus most common worldwide; viridans Strep classic subacute NVE
  • Strep gallolyticus → colon cancer workup mandatory
  • TEE > TTE for prosthetic, complications
  • FDG-PET-CT for prosthetic / CIED > 3 months
  • Empiric vancomycin + ceftriaxone for NVE
  • POET 2019: oral switch after 10d IV is non-inferior in stable patients
  • Surgery indications: HF / persistent bacteremia / abscess / large veg + embolism / fungal
  • Prophylaxis 2024: limited to highest-risk + dental gingival manipulation