The financial impact is due to multiple factors, including but not limited to the costs of device removal, a new device (which would be required in the majority of patients), cardiac and other medical evaluations, diagnostic procedures, surgical interven- tions for infected device removal, new device placement and certain infectious complications, medical therapy of infec- tion, and critical care stays that are often prolonged. Even when a CIED is ultimately proven not to be infected, the cost of an evaluation for device infection among those with S aureus bacteremia is sizable.32 Microbiology Staphylococcal species cause the bulk of CIED infec- tions17,33 40 and account for 60% to 80% of cases in most reported series (Figure 1). A variety of coagulase-negative Staphylococcus (CoNS) species have been described to cause CIED infections.41 CoNS is well recognized as a common cause of microbiological specimen contamination, and thus, repeated isolation of the same species of CoNS with an identical antibiotic susceptibility pattern is desired to support its role as an etiologic agent in CIED infections. Polymicro- bial infection sometimes involves more than 1 species of CoNS.36,40,42 The prevalence of oxacillin resistance among staphylococcal strains has varied among studies, but it is prevalent and should influence initial empirical therapy de- cisions in CIED infections. Corynebacterium species, Propi- onibacterium acnes, Gram-negative bacilli37,38 including Pseudomonas aeruginosa,43 and Candida species account for a minority of CIED infections. Fungi other than Candida44 and nontuberculosis mycobacteria45,46 are rarely identified as pathogens in CIED infection. The microorganisms that cause CIED infections may be acquired either endogenously from the skin of patients or Figure 1. Microbiology of PPM/ICD infections (n 189). From Sohail et al,38 with permission. Baddour et al Cardiovascular Device Infections 461 exogenously from the hospital inanimate environment or from the hands of hospital workers. 