PM1027: Amiodarone Use Prior to Cardiac Transplant in Children Is Associated with Increased Need for Post-transplant Chronotropic Support

Background: The use of amiodarone prior to cardiac transplant (HTx) in adults is associated with worse post-HTx outcomes compared to recipients who did not receive amiodarone. Data are scarce in pediatrics regarding the association of pre-HTx amiodarone use with post-HTx outcomes. We aim to describe and compare pediatric post-HTx outcomes based on use of pre-HTx amiodarone at a large pediatric HTx center.

Methods: We performed a retrospective cohort study of pediatric patients < 18 years of age who underwent HTx from 2014 – 2021. Pre-HTx amiodarone use was defined as patients on amiodarone antiarrhythmic therapy with administration of amiodarone within two weeks pre-HTx. The primary outcome was early mortality defined as higher 30-day and 1-year mortality rates. The secondary outcomes were markers of increased morbidity including primary graft dysfunction (PGD; defined by use of extracorporeal membrane oxygenation [ECMO] or ventricular assist device [VAD]) within 5 days post-HTx, median vasoactive-inotropic score (VIS), the use of isoproterenol, need for antiarrhythmic therapy, need for temporary pacing within 30 days post-HTx, intensive care unit (ICU) length of stay (LOS), and post- HTx hospital LOS. Pre-HTx characteristics and post-HTx outcomes between patients who received amiodarone vs those that didn’t were compared. Within the pre-HTx amiodarone cohort, the association of dose and length of amiodarone therapy were also analyzed as predictors of outcomes.

Results: Of the 201 patients who underwent HTx, 16 patients (8%) were on amiodarone pre-HTx. The median duration of amiodarone use was 145 days [39 – 590] and median dose was 6.5 mg/kg/day [5 – 9.75]. There were no differences in pre-HTx age, sex, race/ethnicity, weight, diagnosis, or VAD use at time of HTx between those who received amiodarone and those that didn’t (Table 1). There were no differences in 30-day mortality, 1-year mortality, or death during study period between the two groups. The use of post-HTx isoproterenol (p = 0.01) and temporary pacing (p = 0.04) were higher in the amiodarone group. No patient who underwent HTx required permanent pacemaker placement. There were no differences in post-HTx PGD/ECMO/VAD, antiarrhythmic therapy, mean VIS, ICU LOS, or post-HTx hospital LOS (Table 2). There was no association of amiodarone dose and length of amiodarone treatment with post-HTx outcomes.

Conclusion: Pre-HTx amiodarone use was less frequent in this single-center pediatric cohort compared to previously published adult data. The increased use of isoproterenol and temporary pacing post-HTx among patients receiving pre-HTx amiodarone suggests that amiodarone may cause sinus node dysfunction in the acute post-operative period requiring chronotropic support. The need for chronotropic support occurred irrespective of amiodarone dose or length of therapy. In comparison to adult data, pre-HTx amiodarone was not associated with other early post-HTx outcomes including PGD and mortality.