Cardiovascular implantable electronic device infection

Background

• Ranges from local pocket infection to bacteremia to endocarditis

Definitions

• Isolated pocket erosion: device or lead exposed through the skin, with or without signs of infection
• Isolated generator pocket infection: localized erythema, swelling, pain, tenderness, warmth, or drainage, with negative blood cultures
• Lead infection: lead vegetation with positive blood cultures

Microbiology

• Gram-positive bacteria (80%)1
  • Staphylococcus species (75%)
    • Staphylococcus aureus (30%), often with acute onset
    • Coagulase-negative staphylococci (40%), most common cause of device pocket infections
  • Others (5%): Enterococcus species, viridans group streptococci, Streptococcus pneumoniae
• Gram-negative bacteria (10%): Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, Strenotrophomonas maltophilia, Acinetobacter xylosoxidans, Acinetobacter baumannii, Citrobacter koseri, Morganella morganii, Haemophilus influenzae, Moraxella catarrhalis
• Fungi (2%): Candida albicans, Aspergillus fumigatus
• Polymicrobial (5%)
• Culture-negative (5%)

Epidemiology

• Occurs in about 2 per 1000 device-years

Risk Factors

• Patient-related: age, CKD, hemodialysis, diabetes mellitus, heart failure, COPD, preprocedure fever, malignancy, skin disorder, immunosuppression, prior CIED infection, anticoagulation
• Procedure-related: pocket intervention (including generator change, upgrade, or lead or pocket revision), pocket hematoma, longer procedure, inexperienced operator, ICD (compared to pacemaker), no prophylactic antibiotics
• Organism-related: highly virulent bacteria such as staphylococci

Clinical Manifestations

• Frequently infected at time of implantation, replacement, or surgical manipulation
• Often starts with generator pocket infection, then infection tracts back up the leads to intravascular and intracardiac parts
  • Local signs of infection followed by fevers, chills, malaise, fatigue, or anorexia
  • Erosion of any part of the device suggests contamination of the entire system
• Can be early (within 6 months) or late (more than 6 months)
  • Early is more likely to present with pocket infection
  • Late more often has bacteremia and endocarditis

Investigations

• Blood cultures, ideally before antibiotics
• Transesophageal echocardiogram in most cases (in strong preference to transthoracic echocardiogram)
• Pacemaker pocket swab at time of removal

Management

• The primary treatment is CIED removal, with adjunctive antibiotics
  • Lead extraction within 3 days of admission is associated with lower mortality

Suspected or confirmed pocket infection

• If early superficial site infection within 30 days of device placement and without systemic signs like fever
  • Oral antibiotics
• If clinical signs of pocket infection, need blood cultures and TEE
  • Remove CIED, including generator and all leads
  • If no bacteremia: treat 2 weeks
  • If bacteremia but TEE negative: treat 2 weeks (or 4 weeks for Staphylococcus aureus)
  • If TEE positive: treat 4 weeks if native vale and 6 weeks if prosthetic valve or endocarditis

Suspected or confirmed CIED infection

• Management depends on blood culture findings ± TEE
  • If bacteremia, get TEE
  • If no bacteremia but high clinical suspicion, get TEE
• If bacteremia (or received prior antibiotics)
  • Valve vegetation ± bacteremia: remove CIED and treat as endocarditis
  • Lead vegetation ± bacteremia: remove CIED and treat for 2 weeks, or 4 weeks for Staphylococcus aureus
  • Negative TEE: consider CIED removal depending on microbiology and treat for 2 weeks
• If no bacteremia
  • TEE positive: treat as above
  • No TEE or TEE negative
    • Pocket site infection or erosion: remove CIED and treat for 2 weeks
    • No pocket site infection: monitor

Bacteremia without focus

• Remove all non-CIED sources
• If ongoing concern for CIED infection:
  • For Staphylococcus aureus, coagulase-negative staphylococci, Cutibacterium acnes, or Candida species: remove CIED
  • For alpha- or beta-hemolytic streptococci, or Enterococcus species: consider CIED removal or close observation
  • For Gram-negative bacilli or Streptococcus pneumoniae: close observation without CIED removal is reasonable

Reimplantation

• After device removal, patients who are pacemaker- or defibrillator-dependent should have a temporary device inserted
  • Epicardial pacing is associated with higher mortality
• For isolated pocket infection, it is reasonable to reimplant on the same day
• For all others, reimplantation of a permanent device should be delayed until:
  • Blood cultures are negative at 72 hours, and
  • All source control is complete (such as drainage of deep abscesses, etc.)
• The device should be reimplanted at a site distant from the first

Further Reading

• 2017 HRS expert consensus statement on cardiovascular implantable electronic device lead management and extraction. Heart Rhythm. 2017;14(12):e503-e551. doi: 10.1016/j.hrthm.2017.09.001