What is the management of endocarditis with vascular involvement?

Management of Endocarditis with Vascular Involvement

The management of endocarditis with vascular involvement requires aggressive antimicrobial therapy, surgical intervention when indicated, and comprehensive monitoring for complications, with treatment duration of at least 4-6 weeks depending on the causative organism and valve type affected. 1, 2

Antimicrobial Therapy

First-line Treatment Based on Causative Organism

• Viridans streptococci or S. bovis:

  • Aqueous crystalline penicillin G (18-30 million U/24h IV in 6 divided doses) or ampicillin (12g/24h IV in 6 divided doses) for 4 weeks if symptoms <3 months, 6 weeks if symptoms >3 months 2

• Enterococci:

  • Penicillin-susceptible: Ampicillin (12g/24h IV) or penicillin G plus gentamicin (3 mg/kg/24h) for 4-6 weeks 2
  • Penicillin-resistant: Vancomycin (30 mg/kg/24h IV) plus gentamicin for 6 weeks 2

• Staphylococci:

  • MSSA Native Valve: Nafcillin or oxacillin 12 g/day IV for 4-6 weeks, plus gentamicin for first 2 weeks 2
  • MRSA Native Valve: Vancomycin 30 mg/kg/day IV for 4-6 weeks 2
  • MSSA Prosthetic Valve: Nafcillin/oxacillin plus rifampin for ≥6 weeks and gentamicin for first 2 weeks 2
  • MRSA Prosthetic Valve: Vancomycin plus rifampin for ≥6 weeks and gentamicin for first 2 weeks 2

Duration of Treatment

• Native valve endocarditis: Minimum 4 weeks for symptoms <3 months, 6 weeks for symptoms >3 months 2
• Prosthetic valve endocarditis: Minimum 6 weeks 2
• Septic thrombosis of great central veins: 4-6 weeks (same as for endocarditis) 1

Management of Vascular Complications

Septic Thrombosis

• Catheter-related septic thrombosis:

  • Remove involved catheter in all cases (A-II) 1
  • For peripheral vein involvement: Incision, drainage, and excision of infected vein and tributaries when there is suppuration, persistent bacteremia/fungemia, or metastatic infection 1
  • Surgical exploration when infection extends beyond the vein into surrounding tissue 1

• Great Central Veins:

  • Heparin therapy is recommended (A-II) 1
  • Duration of antimicrobial therapy should be same as for endocarditis (4-6 weeks) 1
  • For Candida septic thrombosis: Prolonged amphotericin B therapy; fluconazole if strain is susceptible 1

• Arterial Involvement:

  • Surgical excision and repair for peripheral arterial involvement with pseudoaneurysm formation 1

Infectious (Mycotic) Aneurysms

• Intracranial infectious aneurysms occur in 2-4% of IE cases 1
• Detection requires cerebral imaging (CT or MR angiography) in patients with neurological symptoms 1
• Management:
  • Neurosurgery or endovascular therapy is recommended for very large, enlarging, or ruptured intracranial infectious aneurysms 1
  • Conventional angiography should be considered if non-invasive techniques are negative but suspicion remains 1

Surgical Intervention

Indications for Surgery

1. Heart Failure:

   • Aortic/mitral valve IE with severe acute regurgitation, obstruction, or fistula causing refractory pulmonary edema or cardiogenic shock (Emergency surgery) 1, 2
   • Severe regurgitation or obstruction causing symptoms of HF (Urgent surgery) 1

2. Uncontrolled Infection:

   • Locally uncontrolled infection (abscess, false aneurysm, fistula, enlarging vegetation) 1
   • Infection caused by fungi or multiresistant organisms 1
   • Persistent positive blood cultures despite appropriate antibiotic therapy 1
   • PVE caused by staphylococci or non-HACEK gram-negative bacteria 1

3. Prevention of Embolism:

   • Persistent vegetations >10 mm after one or more embolic episodes 1
   • Very large vegetations (>30 mm) 1
   • Large vegetations (>15 mm) with no other indication for surgery 1

Timing of Surgery

• Emergency: Within 24 hours - For cases with refractory pulmonary edema or cardiogenic shock 1
• Urgent: Within a few days - For cases with heart failure, uncontrolled infection, or high embolic risk 1
• Elective: After 1-2 weeks of antibiotic therapy - For stable cases requiring surgery 1

Special Considerations for Neurological Complications

• After silent embolism or TIA: Cardiac surgery, if indicated, without delay 1
• After stroke: Surgery should be considered without delay for HF, uncontrolled infection, abscess, or persistent high embolic risk if coma is absent and cerebral hemorrhage has been excluded 1
• Following intracranial hemorrhage: Surgery should generally be postponed for ≥1 month 1

Monitoring and Follow-up

• Daily clinical assessment during critical phase
• Serial blood cultures until sterilization is documented
• Regular echocardiographic follow-up
• Monitoring of renal function and drug levels:
  • Gentamicin: Trough levels <1 mg/L, peak levels 10-12 mg/L
  • Vancomycin: Trough levels 10-15 μg/mL, peak levels 30-45 μg/mL 2
• Clinical evaluation at 1,3,6, and 12 months post-treatment 2

Multidisciplinary Team Approach

• Early consultation with infectious disease specialists is strongly recommended 2
• The "Endocarditis Team" approach improves outcomes and should include cardiologists, cardiac surgeons, infectious disease specialists, and microbiologists 1

Common Pitfalls and Caveats

1. Delayed diagnosis: Obtain at least 3 sets of blood cultures from separate venipuncture sites before initiating antibiotics 2

2. Inadequate treatment duration: Treatment must be continued for the full recommended duration even if clinical improvement occurs early 1, 2

3. Failure to recognize surgical indications: Regular echocardiographic assessment is crucial to identify complications requiring surgical intervention 1

4. Inappropriate timing of surgery after neurological events: After stroke, surgery should be performed without delay if indicated for heart failure or uncontrolled infection, provided coma is absent and cerebral hemorrhage has been excluded 1

5. Inadequate monitoring: Regular assessment of antibiotic levels, renal function, and clinical response is essential 2