Positive pretransplantation cytomegalovirus serology is a risk factor for cardiac allograft vasculopathy in children

BACKGROUND - Cytomegalovirus (CMV) infection has been implicated as a cause of posttransplantation coronary artery disease in adults. The purpose of this retrospective observational study was to evaluate the effect of CMV on outcome after heart transplantation in children. METHODS AND RESULTS - Risk factors tested were recipient age, sex, and pretransplantation CMV serology; use of anti-CMV prophylaxis; posttransplantation evidence of CMV infection; and donor CMV serology. Transplantations were stratified traditionally according to CMV risk as low risk (recipient negative/donor negative), intermediate risk (recipient positive), and high risk (recipient negative/donor positive). Primary outcome measures were (1) development of coronary artery vasculopathy, (2) mortality (or graft loss) that occurred outside the early postoperative period, and (3) death (or graft loss) due to vasculopathy. Analysis was by proportional hazards modeling. A total of 165 children underwent heart transplantation, with a mean age at transplantation of 7.8 (SD 5.6) years. Thirty-two children had laboratory evidence of CMV infection after transplantation, but only 6 developed CMV disease or syndrome. Traditional CMV risk stratification correlated well with CMV infection but did not predict mortality, coronary artery disease, or coronary death. In contrast, positive recipient CMV was the only independent predictor of all 3 outcome measures: coronary artery disease (hazard ratio=3.6), all-cause mortality (partial hazard ratio=4.1), and coronary death (hazard ratio=4.6). CONCLUSIONS - In children, pretransplantation recipient CMV status is a more powerful predictor for the development of clinically significant vasculopathy and subsequent death than traditional risk stratification. This phenomenon warrants further investigation.