Infectious consequences of antimicrobial change from vancomycin-piperacillin/ tazobactam to vancomycin-cefepime in the prevention of AKI during orthotopic heart transplantation

Abstract Background Empiric antimicrobial selection in orthotopic heart transplantation (OHT) is critically important as post-operative infections are a significant cause of morbidity and mortality. While variability of antimicrobial selection exists between centers, both combinations of vancomycin and piperacillin-tazobactam (VPT) and vancomycin and cefepime (VC) are frequently used. VPT drug combination has been associated with increased risk of acute kidney injury (AKI) in multiple reports. Our study aimed to evaluate the infectious impact of changing the empiric antimicrobial selection from VPT to VC. Methods This was a single-center study in patients who underwent OHT at the Medical University of South Carolina (MUSC) from 2015 through 2021 (n=120). As part of a quality improvement measure, the empiric intraoperative antimicrobial therapy was transitioned from VPT (n=48) to VC (n=72) on 6/20/2019, providing a prospective setting to investigate infectious outcomes. Results A total of 10.4% of patients who received VPT had a positive culture within 30 days of OHT, compared to 9.7% of patients who received VC (p=0.781). All positive cultures were reviewed and deemed to be clinically significant infections. No significant difference in the site of culture positivity was identified between groups (p=0.487). Among patients who developed postoperative infection, there was a trend toward a longer time to infection in patients receiving VPT (median 28 days) than VC (median 14 days), p=0.08. Conclusions Culture-positive infections within 30 days post-OHT were similar between patients receiving empiric intraoperative VPT and those receiving VC. Graphical Abstract