Background: Hypertension is recognized as prevalent in pediatric cardiac transplant recipients. This study investigated risk factors for this complication and, in particular, the role of immunosuppression.
Methods: Results of 24-hour ambulatory blood pressure monitoring of children surviving more than 1 year after cardiac transplantation were analyzed retrospectively. Subjects were designated either hypertensive or normotensive by comparison with published normal values. To identify factors associated with hypertension, clinical data contemporaneous with 24-hour ambulatory blood pressure monitoring were collected and compared between the groups.
Results: In the 51 children studied, the incidence of hypertension was 49%. Hypertensive and normotensive recipients were similar for sex, age at transplantation, time between transplantation and 24-hour ambulatory blood pressure results, and choice of calcineurin inhibitor. In contrast, hypertensive patients were taking significantly more immunosuppressive agents (2.92 vs 2.12 p < 0.01), had higher tacrolimus levels (10 vs 8.1 microg/liter, p = 0.03), and were more likely to be on maintenance prednisone therapy (64% vs 23%, p < 0.01) or regimens including sirolimus (40% vs 12%, p = 0.03). Multiple regression analysis controlling for tacrolimus level showed a combination of prednisone and sirolimus was more strongly associated with hypertension than either agent alone, with an odds ratio of 7.3 (95% confidence interval, 1.5-36.1) vs 4.1 (95% confidence interval, 0.85-26.3).
Conclusions: Hypertension after pediatric cardiac transplantation is a common problem and primarily associated with immunosuppressive regimen.