Lead-Associated Endocarditis: the Important Role of Methicillin-Resistant Staphylococcus Aureus
MedSun: Newsletter #26, July 2008


BACKGROUND: Infection is a potentially life-threatening complication of cardiac device implantation. Lead-associated endocarditis (LAE) may be the most serious complication since it is associated with a high mortality. METHODS: The medical records of patients referred to our institution for the treatment of LAE between 1999 and 2007 were reviewed. RESULTS: A total of 51 of 107 patients referred for device-related infections met the criteria for LAE. Of these, 19 occurred within 6 months of their most recent procedure (early), while the remaining 32 occurred more than 6 months later (mean = 31.9 months post procedure). Devices included pacemakers in 33 patients and ICDs in 18 patients. The most common organism responsible for infection was Staphylococcus aureus (S. aureus) followed by coagulase-negative staphylocci (22%) and streptococci (12%). Methicillin-resistant S. aureus (MRSA) accounted for 67% of the S. aureus infections. Coagulase-negative staphylococci were responsible for only 26% of early and 19% of late cases. A distant site of infection was common (26/51 = 51%), particularly in patients with MRSA LAE. The device and leads were removed percutaneously in all patients. Only one patient failed to respond to intravenous antibiotics. CONCLUSIONS: Our data suggest that methicillin-resistant S. aureus is an important pathogen in LAE. Since many infections occur months after the last device procedure, hematogenous spread of organisms from a distant site may be an important contributing factor. These data suggest that strategies to prevent hematogenous infection, particularly with S. aureus, are critical in patients with implantable cardiac devices.

Additional Information:

Lead-Associated Endocarditis: the Important Role of Methicillin-Resistant Staphylococcus Aureus. Greenspon, AJ; et al. Journal of Pacing and Clinical Electrophysiology. Division of Cardiology, Thomas Jefferson University Hospital, Philadelphia, PA

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