Cardiomegaly Associated With Tacrolimus Use in Pediatric Liver Transplantation

Abstract

Introduction: There have been multiple case reports and autopsy studies associating the use of tacrolimus in organ transplant recipients with the development of cardiomegaly and left ventricular hypertrophy. There has been one prospective study reporting two cases of cardiac toxicity associated with tacrolimus; however, both the cases occurred in patients whose tacrolimus levels were above 30 ng/ml. Further studies are required to evaluate the association between tacrolimus use and cardiotoxicity. We aim to evaluate the association between tacrolimus use within therapeutic drug level goal of 8-12 ng/ml with cardiomegaly in pediatric liver transplant recipients at our institution. Methods: This is a retrospective study involving pediatric liver transplant recipients, with no prior cardiomegaly, who received tacrolimus for maintenance immunosuppression. All patients between the ages of 0-19 years, who were transplanted between January, 2007 to December, 2016, were included in the study. Patients with previous history of cardiomegaly were excluded from the study. We reviewed their electronic medical records for findings of cardiomegaly or ventricular hypertrophy on chest x-ray, EKG, echocardiogram and CT chest. Patients with positive findings on either of these were evaluated for clinically significant cardiac disease based on change in medication or cardiology consultation. Results: Total 63 patients were included in this study. Two patients who died in the immediate post-operative period were excluded from the study. Out of 61 patients, 8 patients (13%) had chest x-ray findings of cardiomegaly or enlargement of cardiac silhouette and 7 patients (11%) had EKG findings of ventricular hypertrophy. Only 2 patients (3%) had positive echocardiogram. None of these patients had any clinical implications of cardiomegaly as evidenced by the absence of cardiology consultation, tacrolimus dose modification or discontinuation. Conclusion: Tacrolimus-related cardiomegaly seems to be associated with higher drug levels. Tacrolimus drug level required for maintenance immunosuppression in liver transplant patients does not seem to be associated with tacrolimus-related cardiomegaly. Thus, tacrolimus can be safely used for long-term immunosuppression in liver transplant patients as long as there is close drug level monitoring.