1540. Left Ventricular Assist Device Driveline Infections: Relapsed Infections and Minimum Inhibitory Concentration Changes

BACKGROUND: Treatment of left ventricular assist device (LVAD) driveline infections (DLIs) pose difficulties given the permanent nature of the LVAD. Few studies have examined the minimum inhibitory concentration (MIC) changes over time or resistance patterns of implicated pathogens causing recurrent infections. METHODS: This retrospective descriptive epidemiology study identified patients with DLIs in the Vanderbilt LVAD registry or INTERMACS data from January 2013 to August 2017. Driveline infections met International Society for Heart and Lung Transplantation definitions in addition to positive driveline drainage, blood, or sternal wound culture. Relapse included a DLI with an organism associated with previous DLI in the preceding year and similar MICs or new resistance to an antibiotic that was utilized. The LVAD registry and chart review were utilized to collect data. Patients were followed until transplant, death, or August 1, 2017. RESULTS: A total of 330 patients underwent LVAD implantation. Thirty (9%) met criteria for DLI. Median duration of follow-up was 26 months (IQR 16, 39). There were 74 courses of infection, 40 new infections, and 34 relapsed infections. Median time to first DLI was 171 days (IQR 83, 403). Most common organisms in new DLIs were S. aureus (MRSA 11, MSSA 10), diptheroids (6), coagulase-negative staphylococci (6), and P. aeruginosa (5). S. aureus was the most common pathogen in patients with DLI associated bacteremia (n = 16) as well as relapsed infection (n = 11). There were 42 MIC changes in nine patients with relapsed infections from S. aureus, P. aeruginosa, and mycobacterium. Median time to first MIC change was 56 days (IQR 36, 88) and type of MIC change was an increase in five cases, decrease in two cases, and both increase and decrease in two cases. Time to first relapse from initial infection was longer in those who received suppression, 60 days vs. 83 days, P = 0.047. CONCLUSION: Few patients had DLIs, but relapsed infections were more common with S. aureus and P. aeruginosa. MIC changes were quite variable and may not be the major contributor to relapsed infection. DISCLOSURES: All authors: No reported disclosures.