P-1000. Evaluating The Efficacy of Oral Vancomycin Primary Prophylaxis to Prevent Clostridioides difficile Infections in Heart Transplant Recipients

Abstract Background Clostridioides difficile is a common cause of hospital-acquired diarrheal infections and immunocompromised patients, including heart transplant patients, are vulnerable to severe Clostridioides difficile infections (CDI). Primary prophylaxis of CDI with oral vancomycin can be utilized in these patients but data regarding efficacy is limited. Methods This was an IRB-approved retrospective observational chart review conducted at North Shore University Hospital evaluating the efficacy of oral vancomycin for primary prophylaxis of CDI in heart transplant recipients admitted between January 2018 and December 2023. The study compared patients who received oral vancomycin prophylaxis (OVP) for CDI with those who did not, based on a protocol change in January 2022. Patients with a history of CDI were excluded. The primary objective was to compare the development of CDI within one-year post-transplant between patients who received OVP and those who did not. The secondary objective was the incidence of vancomycin-resistant Enterococcus infections within one-year post-transplant. Statistical analysis involved Fisher’s exact test for categorical data and Wilcoxon rank-sum test for continuous data. Results The study included 122 patients. Of these, 44 (36%) did not receive OVP, while 78 (64%) did. For the primary outcome, 2 patients developed CDI within one-year post-transplant, both of whom had not received prophylaxis, but this difference was not statistically significant. These patients developed CDI within 24 days and 39 days respectively. For the secondary outcome, 8 patients developed VRE within one-year post-transplant of which 63% (n=5) received prophylaxis. There was no significant difference in VRE development between those who did and did not receive OVP (6.4% vs. 6.8%, respectively). Conclusion This study did not show a benefit for OVP in the prevention of CDI in heart transplant recipients without a history of CDI. However, these results have limitations, primarily due to the low incidence of CDI and the small sample size. Further research is needed to assess the efficacy of oral vancomycin primary prophylaxis in heart and other solid organ transplant recipients. Disclosures All Authors: No reported disclosures