6-month vs 12-month CMV Prophylaxis for CMV-Mismatched Heart Transplant Recipients

Purpose Cytomegalovirus (CMV) infection frequently affects CMV-mismatched (D+/R-) heart transplant (HTx) recipients. Guidelines recommend 3 to 6 months of CMV prophylaxis for D+/R- HTx recipients. Here we sought to assess the effect of an update to our institution CMV prophylaxis protocol in 2017 with a decreased duration from 12 to 6 months postHTx. Methods Retrospective cohort study of adult patients who underwent CMV D+/R- HTx and were followed at our institution from 01/2009-06/2018. Patients were followed until 09/2019. Infections were adjudicated using the CMV Drug Development Forum criteria. Baseline demographic, clinical, serological, and outcomes information were collected. In our study, patients became at risk of mortality at the time of HTx, but entered the observation period for mortality after completion of the prophylaxis protocol. We tested difference in CMV infection using the log-rank test. To assess the association between the new protocol, we developed a Cox proportional hazards regression model adjusted for CytoGam®. Results 55 D+/R- HTx recipients were included. 7/14 (50%) patients in the 6-month prophylaxis protocol had a CMV infection vs 11/41 (37.3%) subjects in the 12-month group (Table 1). There was no statistically significant difference in CMV infection between protocols (log rank p=0.97) (Figure 1). In our model, CMV prophylaxis protocol was not associated with increased CMV infection (HR=0.36 [0.09-1.4]). Conclusion In our study, we found no statistically significant difference in CMV infection and mortality between 6 vs 12-month CMV prophylaxis. This protocol appears safe yet warrants ongoing surveillance.