Microbiological epidemiology of infections related to pace-makers and indwelling cardiac defibrillator

Abstract number: 1733_1427

Tascini C., Bongiorni M., Gemignani G., Soldati E., Leonildi A., Arena G., Capolupo S., Menichetti F.

Background: The cardiology Unit at Cisanello Hospital in Pisa is the Italian reference centre for non invasive, transvenous removal of infected pace-makers (PM) or indwelling cardiac defibrillator (ICD). The aim of the study is to review microbiological findings of PM and ICD infections observed at this Unit in five years period (2000–2005).

Materials and Methods: Retrospective observational study on consecutive patients. All patients with clinically documented PM or ICD infections were enrolled in the study. To define the aetiology of the infections. Catheter leads and/or the infected material from the pocket upon removal were cultured in aerobic and anaerobic solid media.

Results: In the study period PM and ICD leads and generators were removed transvenously from 602 patients. Microbiological documentation was obtained from 451 patients (75%) and 560 different microorganisms were isolated; therefore we had negative culture in 151 patients. In 99 patients infections were polymicrobial. Staphylococci were the most frequently isolated pathogens (474/560–84%). The coagulase-negative staphylococci (CNS) resulted the first pathogen (380) followed by S. aureus (94), methicillin-resistant strains, among staphylococci, were 123/474 (26%). Gram negative rods and fungi are relatively rare. Overall susceptibility were also studied; the classes of antibiotic with good activity were newer quinolones (moxifloxacin and levofloxacin followed by aminoglycosides and glycopeptides).

Conclusions: In our experience PM and ICD infections were mainly caused by Staphylococci, especially CNS, other microorganisms (Gram-negative rods and fungi) were also documented in few cases. The knowledge of the epidemiology of these infections and the susceptibility to antibiotics might be useful for clinicians to start an adequate empiric antibiotic therapy.