Introduction: The incidence of infection in cardiac implanted electronic devices (CIED) varies between 1 and 19%, this wide variation occurs in some degree due to the lack of a proper definition.
Objective: To propose a new definition of infection of CIED based on a retrospective review of infected devices analyzing the site of infection and time of occurrence.
Methods: We performed a review of all infected devices in our institution from 2009 to 2014 and classified them by the time of occurrence, Type I in the first year after the implant and Type II after the first year, and then sub-classified according the clinical presentation, A: endocarditis, B: sepsis without an obvious site of infection, that resolved with the extraction of the CIED, C: pocket infection and D: exteriorization without evidence of local infection.
Results: We analyzed 3300 CIED implanted in 5 years, of which 42 (1.2%) were considered for the analysis as infection. Battery exchange was the variable more associated with infection occurring in 47% of all cases analyzed. A pathogen was isolated in 52% of which 40.5% were gram positive coccus, 19% Staphylococcus aureus and 21% epidermidis. The median for presentation in days for Type I infection was 105 days (12 to 365) and the median for Type II was 808 days (480 to 3285). During the first year Type I C (pocket) was more frequent occurring in 69% or patients. In Type II, exteriorization (D) was more frequent with 63% of the cases and only in 38% a pathogen could be identified compared with 65% in Type I infections, P=0.04.
Impression: Clinical presentation of CIED infection varies significantly if the event occurred during the first year (related to the procedure) or after the first year (not related to the procedure). This classification allows a more precise definition of the event and helps to understand the responsible mechanisms involved, and will help to provide proper information and stablish a better management.