From the Guidelines
For non-MSSA bacteremia with a pacemaker where the bacteremia has cleared, the recommended approach is to remove the pacemaker if possible, as it represents a potential source of ongoing infection. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of removing the device to prevent relapse of infection 1. If the pacemaker cannot be removed due to patient factors, then suppressive antibiotic therapy should be considered. The specific antibiotic regimen depends on the identified organism and its susceptibilities. For example, if dealing with coagulase-negative staphylococci, options include oral doxycycline 100mg twice daily, trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily, or minocycline 100mg twice daily. Duration of therapy would typically be lifelong suppression if the device remains in place.
Some key points to consider in the management of non-MSSA bacteremia with a pacemaker include:
- Complete removal of the pacemaker system, including all leads and the generator, is indicated as part of the early management plan in patients with documented infection of the device or leads 1.
- The likelihood of underlying cardiac device infection in a patient with S. aureus bacteremia is relatively high, and device removal is recommended even without evidence of device or lead infection 1.
- Blood cultures should be repeated 1-2 weeks after completing initial treatment to confirm clearance of bacteremia.
- Regular follow-up with both infectious disease and cardiology specialists is essential to monitor for recurrence of infection and device function.
The rationale for device removal when possible is that biofilms form on cardiac devices, making eradication of infection difficult with antibiotics alone, even after bacteremia has cleared 1. The risk of relapse remains significant if the colonized device stays in place, hence the recommendation for removal when feasible.
From the Research
Management Options for Non-MSSA Bacteremia
In a patient with a pacemaker where the bacteremia has been cleared, management options for non-Methicillin-susceptible Staphylococcus aureus (non-MSSA) bacteremia include:
- Complete hardware removal, which is considered the standard of care 2
- Conservative management with indefinite or prolonged antibiotic therapy, which may be necessary in patients who cannot undergo surgical intervention 2, 3
- Total explantation of pacing material in patients with bacteremia and abnormal images at transoesophageal echocardiography (TEE) 3
- Conservation of the pacing system in patients with bacteremia but without abnormal images at TEE, provided prolonged antibiotic treatment is given 3
Considerations for Treatment
When treating non-MSSA bacteremia in patients with pacemakers, considerations include:
- The risk of infective endocarditis on pacemakers or implantable cardioverter-defibrillators (ICDs) is not negligible and has increased in recent years 4
- The most common germs causing pacemaker endocarditis are staphylococci 4
- Treatment requires prolonged antibiotic therapy and retrieval of the pacemaker and leads 4
- The frequency of permanent pacemaker or ICD infection in patients with gram-negative bacteremia is rare, and no patients appeared to have secondary pacemaker or ICD infection due to hematogenous seeding of the system 5