Incidence and severity of cytomegalovirus infection in seropositive heart transplant recipients.

Background: The frequency and significance of cytomegalovirus (CMV) infection in seropositive (R+) heart transplant recipients (HTR) is unclear, with preventative recommendations mostly extrapolated from other groups. We evaluated the incidence and severity of CMV infection in R+ HTR, to identify risk factors and describe outcomes.

Methods: R+ HTR from 2010 to 2019 were included. Antiviral prophylaxis was not routinely used, with clinically guided monitoring the local standard of care. The primary outcome was CMV infection within one-year post-transplant; secondary outcomes included other herpesvirus infections and mortality.

Results: CMV infection occurred in 27/155 (17%) R+ HTR. Patients with CMV had a longer hospitalization (27 vs. 20 days, unadjusted HR 1.02, 95% CI 1.00-1.02, p = .01), higher rate of intensive care readmission (26% vs. 9%, unadjusted HR 3.46, 1.46-8.20, p = .005), and increased mortality (33% vs. 8%, unadjusted HR 10.60, 4.52-24.88, p < .001). The association between CMV and death persisted after adjusting for multiple confounders (HR 24.19, 95% CI 7.47-78.30, p < .001). Valganciclovir prophylaxis was used in 35/155 (23%) and was protective against CMV (infection rate 4% vs. 27%, adjusted HR .07, .01-.72, p = .025), even though those receiving it were more likely to have received thymoglobulin (adjusted OR 10.5, 95% CI 2.01-55.0, p = .005).

Conclusions: CMV infection is common in R+ HTR and is associated with a high burden of disease and increased mortality. Patients who received valganciclovir prophylaxis were less likely to develop CMV infection, despite being at higher risk. These findings support the routine use of antiviral prophylaxis following heart transplantation in all CMV R+ patients.