What are the management considerations for a patient with Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia and a pacemaker, now that the bacteremia has been cleared?

From the Guidelines

For a patient with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia who has a pacemaker but whose bloodstream infection has cleared, complete device removal is strongly recommended despite negative blood cultures. The standard approach involves extracting the entire pacemaker system (generator and leads) followed by 2-4 weeks of intravenous antistaphylococcal beta-lactam therapy such as nafcillin or oxacillin (2 grams IV every 4 hours), or cefazolin (2 grams IV every 8 hours) if the patient has a penicillin allergy without anaphylaxis, as recommended by the American Heart Association 1. The duration of therapy should be counted from the first negative blood culture after device removal. Device retention carries a high risk of relapse and treatment failure because bacteria can form biofilms on device surfaces that antibiotics cannot effectively penetrate, as noted in the guidelines for the management of patients with valvular heart disease 1. Even with cleared bacteremia, microscopic colonization of the device likely persists. After completing therapy and ensuring infection clearance (with negative blood cultures), a new pacemaker can be implanted, typically on the contralateral side, as suggested by the update on cardiovascular implantable electronic device infections and their management 1. During the interim period without a pacemaker, temporary pacing may be required depending on the patient's underlying rhythm and pacing dependency. Key considerations in the management of such patients include:

• Complete removal of the pacemaker system to prevent relapse and treatment failure
• Use of appropriate antimicrobial therapy based on the causative organism and its susceptibility
• Timing of new device placement, which should be based on clinical assessment and negative blood cultures
• The need for temporary pacing during the interim period without a pacemaker. It is essential to follow the guidelines and recommendations from reputable sources, such as the American Heart Association, to ensure the best possible outcomes for patients with MSSA bacteremia and a pacemaker.

From the FDA Drug Label

Duration of therapy varies with the type of severity of infection as well as the overall condition of the patient, therefore it should be determined by the clinical and bacteriological response of the patient In severe staphylococcal infections, therapy with oxacillin should be continued for at least 14 days. Therapy should be continued for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative.

The management considerations for a patient with Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia and a pacemaker, now that the bacteremia has been cleared, include:

• Continuing therapy with oxacillin for at least 14 days in severe staphylococcal infections
• Continuing therapy for at least 48 hours after the patient has become afebrile, asymptomatic, and cultures are negative
• Determining the duration of therapy based on the clinical and bacteriological response of the patient 2

From the Research

Management Considerations for MSSA Bacteremia with a Pacemaker

• The management of a patient with Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia and a pacemaker, now that the bacteremia has been cleared, involves several considerations, including the choice of antibiotic therapy and the management of the pacemaker.
• The choice of antibiotic therapy is crucial in the management of MSSA bacteremia. Studies have shown that cefazolin is a effective alternative to antistaphylococcal penicillins for the treatment of MSSA bacteremia 3.
• Ceftriaxone has also been shown to be effective in the treatment of MSSA bacteremia, with once daily dosing and a short infusion time, making it a promising alternative for outpatient antibiotic infusion 4, 5.
• The management of the pacemaker is also important, as MSSA bacteremia can increase the risk of pacemaker-related infections. Studies have shown that the combination of cefazolin and ertapenem can rapidly clear persistent MSSA bacteremia, including in cases of endocarditis 6.
• Adequate source control, such as removal of the pacemaker, may be necessary to prevent recurrence of infection.
• The use of cefazolin or ceftriaxone as salvage therapy may be considered in cases of persistent MSSA bacteremia, especially in patients with a pacemaker.
• It is essential to note that the management of MSSA bacteremia with a pacemaker should be individualized, taking into account the patient's specific clinical situation and the results of susceptibility testing 7, 3.