OBJECTIVES: Evaluate the time course of thrombocytopenia in patients with Impella devices (Abiomed, Danvers, MA). DESIGN: This was a retrospective, multicenter review of electronic medical records at a large hospital system from April 2018 to August 2020. SETTING: Electronic medical records of patients at SSM Health hospitals were reviewed. PATIENTS: Patients 18–89 years old admitted to an SSM Health hospital from April 2018 to August 2020 who received greater than or equal to 24 hours of percutaneous mechanical circulatory support (pMCS) with an Impella device were included. Exclusion criteria were use of other pMCS devices, history of heparin-induced thrombocytopenia (HIT), and presence of device upon transfer from an outside hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Ninety-three patients were included. The median duration of pMCS was 63.5 hours. Thrombocytopenia occurred in 86% of patients and was evident 24 hours after device placement. The platelet nadir occurred 84 hours after device placement. Platelet recovery occurred 86.5 hours after device removal. The duration of thrombocytopenia was 156 hours. Signs of hemolysis were present in 44.09% of patients, were evident 12–24 hours after device placement, and resolved after device removal. CONCLUSIONS: Thrombocytopenia occurred in the majority of patients and was evident 24 hours after device placement. The time course of thrombocytopenia mirrored that of hemolysis.

Background Data is limited comparing oritavancin (ORT) to the standard-of-care (SOC) for the treatment gram-positive blood stream infections (BSI). Methods This was a retrospective study of all patients in the Veteran’s Affairs Health Care System treated with at least 1 dose of oritavancin or at least 5 days of vancomycin, daptomycin, ceftaroline, ampicillin, ampicillin-sulbactam, nafcillin, oxacillin, or cefazolin for a documented gram-positive BSI from 1 January 2015 to 30 June 2021. Patients with polymicrobial blood cultures or positive cultures from other sites were included if the organisms were sensitive to the incident antimicrobial; no concomitant antimicrobials could be used once the incident agent was started. Individuals were also excluded if they were diagnosed with endocarditis, had a neutrophil count < 500 cells/mm3, or had a diagnosis of Human Immunodeficiency Virus (HIV) on their problem list. The primary composite outcome was clinical failure, defined as all-cause mortality within 30-days from the end of therapy, or blood cultures positive for the incident organisms ≥72 hours after administration of the first dose and ≤30 days after the administration of the final dose of the study antimicrobial, or any drug or line-related readmissions within 30-days of hospital discharge. Secondary outcomes included all-cause 30-day readmission and rates of acute kidney injury (AKI). Results Two hundred-forty patients were identified for screening with 96 meeting criteria (27 in ORT and 69 in SOC groups). Baseline characteristics were generally balanced between groups except more patients in the ORT group received > 96-hours of treatment before the incident antimicrobial was started (70.3% (19/27) vs. 13.04% (9/69); p<0.001). The pathogen most prevalent was methicillin-susceptible Staphylococcus aureus (MSSA) (ORT 33.3% (9/27) vs. SOC 46.4% (32/69)). Clinical failure occurred in 7.4% (2/27) in the ORT group and 17.4% (12/69) in SOC (p=0.34). No components of the primary outcome were significantly different between groups, but AKI did occur more commonly in the SOC group (27.5% (19/69) vs. 3.7% (1/27); p=0.01). Conclusion ORT appears to be a safe and effective option when directly compared to the SOC for non-endocarditis BSIs. Disclosures Ryan P. Moenster, Pharm.D., FIDSA, Melinta Therapeutics: Grant/Research Support|Melinta Therapeutics: Honoraria.