What is the best approach for managing infections of intracardiac devices in patients?

Management of Intracardiac Device Infections: An Infectious Disease Perspective

Immediate Diagnostic Approach

Complete device and lead removal combined with prolonged antimicrobial therapy is the cornerstone of management for all definite cardiovascular implantable electronic device (CIED) infections, including those with valvular/lead endocarditis, sepsis, or pocket infections. 1

Initial Workup

• Obtain at least 2 sets of blood cultures before initiating antibiotics in all patients with suspected CIED infection—this is a Class I recommendation that guides subsequent pathogen-directed therapy 1, 2, 3

• Perform immediate device interrogation to assess device function and rule out device malfunction as cause of symptoms 2

• Conduct baseline evaluation including history, physical examination, chest radiograph, electrocardiogram, and device interrogation before device removal 1

Echocardiographic Evaluation

• Transthoracic echocardiography (TTE) should be performed first in all patients with suspected CIED infection (Class I recommendation), as it is safe, widely available, and can detect functional consequences 1

• Transesophageal echocardiography (TEE) is mandatory when TTE is non-diagnostic, when blood cultures are positive, or when clinical suspicion remains high despite negative TTE—TEE has approximately 90% sensitivity for detecting lead infections and prosthetic valve vegetations compared to only 25-40% for TTE 1, 2, 3

• TEE is particularly critical for evaluating lead vegetations, valvular endocarditis, and perivalvular complications like abscesses 1, 2

• Repeat TTE and/or TEE within 5-7 days if initial examination is negative but clinical suspicion remains high 1

Advanced Imaging for Equivocal Cases

• FDG PET/CT should be used when echocardiography findings are inconclusive or equivocal, as it detects inflammatory cells early before morphological damage occurs and is not affected by device artifacts 1

• Cardiac CT angiography adds value for assessing perivalvular tissues (abscesses, fistulas, pseudoaneurysms) important for surgical planning 1

Risk Stratification for Device Infection

High-Risk Features Suggesting CIED Infection

The following clinical parameters indicate likely CIED infection in patients with bacteremia but no localizing signs 1, 2:

• Relapsing bacteremia after appropriate antibiotic therapy
• No other identified source for bacteremia
• Bacteremia persisting >24 hours
• Device is an ICD (higher risk than pacemaker)
• Presence of prosthetic cardiac valve
• Bacteremia within 3 months of device placement

Organism-Specific Considerations

• Staphylococcus aureus bacteremia with CIED: Device removal is recommended for occult staphylococcal bacteremia (Class I, Level B) 1

• Gram-negative bacteremia: CIED infection is unlikely with Gram-negative organisms unless bacteremia is relapsing or persistent despite appropriate therapy with no other defined source 1

• Coagulase-negative staphylococci, streptococci, enterococci, Candida: Limited data exist, but risk appears lower; however, more evidence is needed for definitive recommendations 1

• Staphylococcus lugdunensis: Manage similarly to S. aureus due to high virulence and endocarditis potential 3

Indications for Complete Device Removal

Class I Recommendations (Must Remove)

Complete device and lead removal is mandatory in the following scenarios 1:

1. Definite CIED infection with valvular and/or lead endocarditis or sepsis (Level of Evidence: A)
2. CIED pocket infection with abscess formation, device erosion, skin adherence, or chronic draining sinus (Level of Evidence: B)
3. Valvular endocarditis without definite lead involvement (Level of Evidence: B)
4. Occult staphylococcal bacteremia (Level of Evidence: B)
5. Locally uncontrolled infection including abscess, false aneurysm, fistula, or enlarging vegetation (Level of Evidence: B) 1
6. Infection caused by fungi or multiresistant organisms (Level of Evidence: C) 1

Class III Recommendations (Do Not Remove)

• Superficial or incisional infection without device/lead involvement 1
• Relapsing bloodstream infection from a source other than CIED requiring long-term suppressive antimicrobials 1

Removal Technique

• Percutaneous extraction is recommended in most patients with CIED-related infective endocarditis, even those with vegetations >10 mm 1

Antimicrobial Therapy

Empiric Therapy

• Target staphylococci empirically, as they are the predominant pathogens (58-87% of coagulase-negative staphylococci are methicillin-resistant) 3

• Vancomycin is the appropriate first-line empiric agent in settings with elevated MRSA prevalence 3

• Tailor therapy based on pathogen identification and susceptibility results (Class I, Level of Evidence: B) 1, 3

Duration of Antimicrobial Therapy (Class I Recommendations)

Duration should be counted from the day of device explantation 1:

• 10-14 days after CIED removal for pocket-site infection (Level of Evidence: C) 1, 3

• At least 14 days after CIED removal for bloodstream infection without complications (Level of Evidence: C) 1, 3

• 4-6 weeks for complicated infection including endocarditis, septic thrombophlebitis, osteomyelitis, or persistent bloodstream infection despite device removal (Level of Evidence: C) 1, 3

• Treatment can be extended beyond 4 weeks if metastatic septic complications develop 1

Microbiological Sampling

• Obtain generator-pocket tissue Gram stain and culture plus lead-tip culture when device is explanted to confirm diagnosis and pathogen 3

New Device Reimplantation Strategy

Timing of Reimplantation

Blood cultures must be negative for at least 72 hours before new device placement if cultures were initially positive (Class IIa, Level C) 1, 2, 3:

• For pocket infection with negative blood cultures: Implant if repeat blood cultures remain negative for 72 hours 1

• For lead vegetations only (positive blood cultures, negative TEE for valve involvement): Implant new CIED if repeat blood cultures remain negative for 72 hours 1

• For valve vegetation: Implant new CIED after 14 days from first negative blood culture 1, 2

Reassessment of Need

• Reassess the need for reimplantation after device extraction—one-third to one-half of patients may not require new CIED placement 1, 2

• Temporary pacing is not routinely recommended 1

Special Surgical Considerations

Urgent Surgery Indications

Urgent surgery is required for 1:

• Severe valve regurgitation or obstruction causing heart failure symptoms or poor hemodynamic tolerance
• Persistent vegetations >10 mm after ≥1 embolic episode despite appropriate antibiotics
• Locally uncontrolled infection

Neurological Complications

• After silent embolism or transient ischemic attack, cardiac surgery should proceed without delay if indicated 1

• Following intracranial hemorrhage, surgery should generally be postponed for ≥1 month 1

Key Clinical Pitfalls

• Do not rely on TTE alone for CIED infections—sensitivity is only 25-40% for lead infections; TEE is essential 1

• Do not attempt to treat CIED infections with antibiotics alone without device removal—cure is rarely possible due to biofilm formation, and this approach carries high morbidity and mortality 4

• Do not reimplant devices prematurely—ensure adequate clearance of bacteremia with negative blood cultures for specified durations 1, 2, 3

• Do not overlook atypical organisms—Mycobacterium fortuitum has been increasingly implicated in CIED infections and requires specific antimicrobial sensitivities 5

• Do not forget to evaluate for metastatic infections—hematogenous dissemination can seed devices from distant sources like diabetic foot ulcers 6

Consultation and Follow-up

• Consultation with infectious disease specialists or cardiologists is recommended (Class IIa) for patients with fever or bloodstream infection without initial explanation who have implanted devices 2, 3

• Repeat blood cultures after device removal if initially positive, and monitor for signs of septic complications including metastatic infections 2