Risk factors associated with cytomegalovirus infection in heart transplant patients: a prospective, epidemiological study

Background The objectives of this epidemiological, prospective study were to describe the characteristics of cytomegalovirus (CMV) infection in heart transplant (HT) recipients and to identify the variables that may influence the development of CMV viremia and CMV disease in these patients. Methods HT recipients >= 18 years of age (n=199) were included in the study. Variables studied included CMV serostatus, immunosuppressive treatment, and administration of anti-CMV prophylaxis. Results The mean age of the population was 52 years, and 84% were males. Immunosuppressive regimens were administered as induction therapy to 92.5% of patients; 88.5% of patients received calcineurin inhibitors as maintenance therapy. Anti-CMV treatment was given to 59% of 199 patients as prophylaxis (70%), preemptive therapy (10%), or to treat CMV infection (20%). Overall, 43% of patients had at least 1 positive viremia test. No patient with a high-risk serostatus (donor+/recipient-) receiving prophylaxis developed CMV syndrome, and only 2.5% of 199 patients developed CMV invasive disease. Multivariate analysis showed that having a positive donor CMV serostatus was associated with an increased risk of developing CMV viremia (P < 0.012), while use of mammalian target of rapamycin (mTOR) inhibitors was associated with a decreased risk (P=0.005). Conclusions In a population of HT recipients, the CMV infection rate was similar to that seen in previous studies, but the progression to overt CMV disease was very low. Having a CMV-positive donor was identified as an independent risk factor for developing CMV viremia, while the use of mTOR inhibitors was protective against viremia.