Risk of Cytomegalovirus Infection after 3 or 6 Months of Valganciclovir Prophylaxis among Donor-Seropositive, Recipient-Seronegative Heart Transplant Recipients.

Background: Cytomegalovirus (CMV) disease is frequent following heart transplant, especially among patients with donor-seropositive, recipient-seronegative (D+/R-) CMV status. Valganciclovir prophylaxis for 3 to 6 months is recommended, but few data support the use of 6 rather than 3 months of prophylaxis for patients who have undergone heart transplant.

Objective: To compare the risk of CMV infection and a first occurrence of CMV disease after heart transplant among CMV D+/R- patients who received 3 or 6 months of prophylaxis in the first year after transplant.

Methods: This retrospective analysis included every D+/R- heart transplant recipient at the study centre between October 2015 and October 2022. Patients had to have a minimum of 1 year of follow-up for inclusion.

Results: Thirty-five patients met the inclusion criteria. The duration of valganciclovir prophylaxis (determined by the medical team) was 3 months for 22 patients and 6 months for 13 patients. CMV infection occurred in 68.2% (15/22) and 30.8% (4/13) of the 3-month and 6-month groups, respectively (risk difference 37.4%, 95% confidence interval [CI] 1.75 to 65.8, p = 0.04). CMV disease occurred in 54.5% (12/22) of patients who received 3 months of prophylaxis and 23.1% (3/13) of those who received 6 months of prophylaxis (risk difference 31.4%, 95% CI -3.7 to 59.4, p = 0.09). Most CMV infections and diseases occurred in the 3 months after the end of prophylaxis.

Conclusions: After heart transplant, CMV D+/R- patients who received 3 months of prophylaxis had a higher risk of CMV infection and a non-statistically significant higher risk of CMV disease relative to those who received 6 months of prophylaxis.