Clinical Presentation, Management, and Outcomes of Cardiovascular Implantable Electronic Device Infections Due to Gram-Negative Versus Gram-Positive Bacteria

Objective: To describe and compare the clinical presentation, management, and outcomes of cardiovascular implantable electronic device (CIED) infections due to gram-negative bacteria (GNB) and CIED infections due to gram-positive bacteria (GPB). Patients and Methods: We retrospectively reviewed all CIED infection cases at Mayo Clinic from January 1, 1992, through December 31, 2015. Cases were classified based on positive microbiology data from extracted devices or blood cultures. Results: Of the 623 CIED infections during the study period, 31 (5.0%) were caused by GNB and 323 (51.8%) by GPB. Patients in the GNB group were more likely to present with local inflammatory findings at the pocket site (90.3% vs 72.4%; P=.03). All patients with bacteremia due to GNB had concomitant pocket infection compared with those with GPB (100% vs 33.9%; P=.002). After extraction, 41.9% of patients in the GNB group were managed with oral antibiotics vs 2.4% in the GPB group (P<.001). There were no statistically significant differences in infection relapse/recurrence or 1-year survival rates between the 2 groups. Conclusion: Compared with CIED infections caused by GPB, those due to GNB are more likely to present with pocket infection. Device-related GNB bacteremia almost always originates from the generator pocket. After extraction, oral antibiotic drug therapy may be a reasonable option in select cases of pocket infections due to GNB. No difference in outcomes was observed between the 2 groups.