Background: Heart-lung transplant is the treatment of choice for the end-stage disease to improve the survival and the overall quality of life. One of the major causes of the morbidity and hospitalization after the heart-lung transplant is cytomegalovirus (CMV) infection. The major determinant of CMV infection includes the donor (D) and recipient (R) serological status present (+) or absent (-) at the time of transplant. Different category of serostatus include high risk (D+/R-), intermediate risk (D+/R+, D-/R+) and low risk (D-/R). The risk of CMV infection is also related to the immunosuppressive protocol. Our aim was to identify if age, sex, or anti-thymocyte immunoglobulin (ATG) immunosuppressive therapy are associated with mortality in heart-lung transplant patients.
Methods: We retrospectively analyzed heart-lung transplant patients identified within the United Network for Organ Sharing (UNOS) database. For mortality data, differences in donor-recipient CMV serostatus were evaluated using unadjusted and adjusted logistic regression models. SAS v. 9.4 was used for statistical analysis with p < .05 used to indicate statistical significance.
Results: Of the 79,015 patients who had a heart and/or lung transplant, CMV serostatus data was available for 49,294 patients (62%). All 49,294 patients had gender and age data; however, only 3,080 (6%) had ATG induction data. The overall mortality rate was 39%, with statistically significant differences in mortality rate observed between the low and intermediate risk groups (36% vs. 40%; p < 0.001) and between the low and high risk groups (36% vs. 39%; p < 0.001). After adjusting for age, sex, and ATG induction at discharge, low risk patients had 21% lower odds of dying compared to high risk patients (95% CI = 1% to 37%; p = 0.040). The effect of serostatus on mortality was not moderated by age, biological sex, or ATG induction at discharge. Finally, a 1% increase in the odds of dying was observed between patients who were one-year older at transplant (p = 0.006), and patients who received ATG induction at discharge had 54% lower odds of dying relative to patients who did not receive ATG induction (p < 0.001).
Conclusion: Serostatus had the exclusive effect on mortality with higher mortality rate in high risk group compared to low risk serostatus group. Young population group had lower mortality rate and ATG induction therapy tends to lower the mortality rate.