592. Antimicrobial Utilization in Solid Organ Transplant Recipients 12-Months Post-Transplantation

Abstract Background Antimicrobials are widely used in solid organ transplant recipients (SOTr). Yet, antimicrobial utilization in the transplant (TP) population is not well characterized. National Healthcare Safety Network antimicrobial use (NHSN-AU) does not provide data specific to SOTr. This study sought to describe inpatient antibiotic use among SOTr up to 1-year post-TP. Methods A cross-sectional study was performed of all SOTr who received a TP between January 2015 to December 2016. Demographics, TP type, antibiotic use variables, hospital days, and Clostridioides difficile infection (CDI) are described. Inpatient antibiotic administration was measured for 365 days starting from date of TP surgery. Automated data generated for NHSN-AU reporting was utilized, and SOTr data was abstracted by cross-matching with the transplant database. Transplant-patient days was used as the denominator for metrics. Variables included duration of therapy (DOT), DOT/1000 patient days, antimicrobial free days (inpatient days no antimicrobials were administered), and NHSN-AU reporting targets of anti-methicillin resistant S. aureus (MRSA), broad spectrum, and high-risk CDI agents. Data was analyzed using descriptive statistics via Microsoft Excel®. Results A total of 530 SOTr were analyzed. Baseline characteristics are shown in Table 1. Median age was 61, male gender 64%, median Charlson Comorbidity Index was 5. Kidney TP (43%), liver TP (32%), lung (9%) and heart (8%) were most common TP types. Among these four TP types: Lung TP had the highest median DOT (13 days), DOT/1000 patient days (6.6) and ratio of DOT/total patient (1.9) (Table 2). Liver TP had the most antimicrobial free days (34%). Proportionally, anti-MRSA agents use was highest in thoracic TP (lung/heart), broad-spectrum agent use was common in all but kidney TPs, and high-risk CDI agents use was highest among kidney TP (Table 3). A total of 34 SOTr had CDI, 76% in kidney/liver TPs. Table 1. Antimicrobial usage and SOT - ID Week 2021 Table 2. Antimicrobial usage and SOT - ID Week 2021 Table 3. Antimicrobial usage and SOT - ID Week 2021 Conclusion Our study provides preliminary and important data of inpatient antibiotic utilization specifically in SOTr, generated using automated NHSN-AU data cross-matched to transplant database. These metrics can be utilized to promote antimicrobial stewardship efforts directed to specific TP types. Disclosures Rachel Kenney, PharmD, Medtronic, Inc. (Other Financial or Material Support, spouse is an employee and shareholder)

Conclusion. This meta-analysis yield data that suggests fluconazole might be inferior to other agents in preventing IFI in all intent to treat patients undergoing HSCT. However, fluconazole is non-inferior in preventing proven IFI and candidiasis IFI based on our results. Thus, we continue to recommend fluconazole in selected patients who require anti-fungal prophylaxis. More RCTs are needed in the future to demonstrate the drug of choice for anti-fungal prophylaxis and address patient selection characteristics.
Disclosures. Background. Antimicrobials are widely used in solid organ transplant recipients (SOTr). Yet, antimicrobial utilization in the transplant (TP) population is not well characterized. National Healthcare Safety Network antimicrobial use (NHSN-AU) does not provide data specific to SOTr. This study sought to describe inpatient antibiotic use among SOTr up to 1-year post-TP.

Methods.
A cross-sectional study was performed of all SOTr who received a TP between January 2015 to December 2016. Demographics, TP type, antibiotic use variables, hospital days, and Clostridioides difficile infection (CDI) are described. Inpatient antibiotic administration was measured for 365 days starting from date of TP surgery. Automated data generated for NHSN-AU reporting was utilized, and SOTr data was abstracted by cross-matching with the transplant database. Transplant-patient days was used as the denominator for metrics. Variables included duration of therapy (DOT), DOT/1000 patient days, antimicrobial free days (inpatient days no antimicrobials were administered), and NHSN-AU reporting targets of anti-methicillin resistant S. aureus (MRSA), broad spectrum, and high-risk CDI agents. Data was analyzed using descriptive statistics via Microsoft Excel®.
Results. A total of 530 SOTr were analyzed. Baseline characteristics are shown in Table 1. Median age was 61, male gender 64%, median Charlson Comorbidity Index was 5. Kidney TP (43%), liver TP (32%), lung (9%) and heart (8%) were most common TP types. Among these four TP types: Lung TP had the highest median DOT (13 days), DOT/1000 patient days (6.6) and ratio of DOT/total patient (1.9) ( Table 2). Liver TP had the most antimicrobial free days (34%). Proportionally, anti-MRSA agents use was highest in thoracic TP (lung/heart), broad-spectrum agent use was common in all but kidney TPs, and high-risk CDI agents use was highest among kidney TP (Table 3). A total of 34 SOTr had CDI, 76% in kidney/liver TPs.  Table 3. Antimicrobial usage and SOT -ID Week 2021 Conclusion. Our study provides preliminary and important data of inpatient antibiotic utilization specifically in SOTr, generated using automated NHSN-AU data cross-matched to transplant database. These metrics can be utilized to promote antimicrobial stewardship efforts directed to specific TP types.
Disclosures Background. The utility of surveillance bronchoscopy (SB) in asymptomatic lung transplant recipients (LTR) is controversial. Guidelines regarding the timing of SB and diagnostic testing varies across centers. Studies evaluating the role of microbiologic testing are lacking. Our transplant institute currently performs SB at week 1, and months 1, 3, 6, 9, 12, and 24 post-transplant. We evaluated if routine microbiologic testing obtained during SB impacted clinical management.
Methods. This observational cohort study was performed at Henry Ford Hospital, Detroit, MI and included all LTR done from August 2014 to August 2019. Clinical and laboratory data was abstracted from the electronic medical record Pre/post-SB. Bronchoscopies performed for new or worsening respiratory symptoms, decline in forced expiratory volume at one second ≥10%, new radiographic abnormalities and follow up bronchoscopies to assess stents or recent acute rejection were excluded. Microbiologic tests assessed are shown in Table 2. Management change was defined as reduction in immunosuppression or prescription of antimicrobials. Rate of change in clinical management based on microbiologic test positivity was the primary outcome. Data were analyzed with descriptive statistics.
Results. 449 SB in 107 LTR were evaluated. Median age was 63 years, 68% were male. The average number of SB performed per patient was 4.2 (Table 1). The most common microbiologic tests performed were bacterial (435), mycobacterial (427), and fungal including Pneumocystis jirovecii (1022) ( Table 2). The rate of test positivity and resultant change in management are shown in Table 3. The rate of test positivity was highest for bacterial (54%), fungal (27%) and viral tests (6%) with management changes in 12%, 2%, and 3% respectively. Conclusion. This is the largest study to specifically evaluate the role of routine microbiologic tests during SB in LTR. Bacterial cultures may be appropriate due to higher rates of management changes. However, routine fungal, AFB, and viral studies are unnecessary due to low true positivity, and consequent low rate of management changes. This represents an important opportunity for diagnostic and antimicrobial stewardship. Background. Patients (pts) with newly diagnosed acute myeloid leukemia (AML) undergoing induction chemotherapy are at increased risk for invasive fungal infections (IFI). Guidelines recommend posaconazole prophylaxis (ppx), but use is precluded by interactions and adverse effects. Micafungin (MCF) is an alternative, but data is limited by small prospective and retrospective studies. Primary objective: describe incidence of probable/proven IFI until neutrophil recovery (ANC ≥ 500 cells/µL) or 28 days after induction start date, whichever occurred first, in pts receiving MCF ppx. Secondary objective: describe incidence of clinical failure to MCF prophylaxis.

Micafungin Prophylaxis in Acute Myeloid Leukemia Adult Patients Undergoing Induction Chemotherapy
Methods. Retrospective review (January 2017 to January 2020) of newly diagnosed AML adult pts undergoing 7 + 3 using idarubicin (7 + 3-ida), 7 + 3 using daunorubicin (7 + 3-dau), venetoclax/decitabine (VEN/DEC), or venetoclax/azacitadine (VEN/AZA) receiving MCF ppx for at least 7 days included. Diagnosis of IFI < 30 days prior to induction, liver function tests (LFT) 5x ULN at start of induction, or evidence of refractory disease after induction excluded. Probable/proven IFI defined by EORTC criteria. Clinical failure: changing to a different antifungal class for any reason until ANC recovery or 28 days after induction start date.
Conclusion. Our findings suggest that prophylactic MCF is safe and effective in pts with newly diagnosed AML undergoing induction chemotherapy. Outcomes were similar to those of prophylactic posaconazole studies, indicating MCF may be considered as an alternative when interactions and adverse effects preclude use of posaconazole. Our study was limited by small numbers, retrospective, single-center design. Future opportunities include prospective trials of prophylactic MCF in this setting.
Disclosures. All Authors: No reported disclosures