Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials in a Large Population of Patients with Cardiovascular Implantable Electronic Device Infection

Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials. Introduction: The incidence of cardiovascular implantable electronic device (CIED) infection is steadily increasing. However, no consensus has been reached with respect to the type and duration of antimicrobial therapy in this specific population of patients. The role played by new anti-Staphylococcus agents has not been defined. The aims of this study were to describe the microbiological characteristics of a large population of patients with CIED infections and to test the in vitro susceptibility of the various strains to different antimicrobials. Methods: Two hundred eighty-six patients with CIED infection were included. The minimal inhibitory concentrations of 9 antimicrobials, including linezolid, tigecycline, and daptomycin were measured against all strains of staphylococci isolated. Results: Microbiologic confirmation was obtained in 252 (88%) patients, the vast majority were from Staphylococcus species (86%), 90% of these were coagulase negative strains and 10% were Staphylococcus aureus; 30.5% were methicillin-resistant. All strains were susceptible to vancomycin, nearly 15% of coagulase negative strains were nonsusceptible to teicoplanin, and nearly 100% of the strains were susceptible to the 3 new antimicrobials. Conclusions: In this large contemporary study, we show that Staphylococcus is by far the most common cause of CIED infections, with the majority due to coagulase negative strains. Methicillin-resistance is common in this population. Currently, we would recommend vancomycin as first-line empirical therapy. However, given that not all patients tolerate vancomycin, we believe that newer antimicrobial therapies should now be tested in clinical trials to establish their clinical effectiveness in treating patients with device infections. (J Cardiovasc Electrophysiol, Vol. 23, pp. 375-381, April 2012)