An Examination of Ventricular Assist Device Duration Prior to Heart Transplant in Children.

Recent data demonstrate worse heart transplant (HTx) outcomes in children with shorter VAD durations, but do not account for VAD adverse events (AEs)Es. We compared outcomes of patients bridged to HTx with < 30 vs. ≥ 30 days of VAD support in an earlier era by assessing both VAD and HTx risk factors. We merged data from the PediMACS and Pediatric Heart Transplant Study registries to compare one-year post-HTx mortality in patients with < 30 vs. ≥ 30 days of pre-HTx VAD support between 2012 and 2018. We used inverse probability of treatment weighting using propensity scores (PS) to control for confounders, including age, blood type, allosensitization, cardiac diagnosis (cardiomyopathy, congenital heart disease, or myocarditis), VAD support type (left, right, single, or biventricular VAD), and pre-Tx mechanical ventilation and vasoactive support. Among 271 patients, there were 60 in the < 30-days and 211 in the ≥ 30-days groups. At HTx, the < 30-days group used more ventilation (34% vs. 7%, p < 0.001) and vasoactives (60% vs. 24%, p < 0.001 vs. ≥ 30-days). The weighted AE rate/patient was 0.42 in the < 30-days vs. 0.78 in the ≥ 30-days group (p = 0.02). There were 2 deaths in the < 30-days group and 13 in the ≥ 30-days group (p = 0.38). A PS-weighted Cox model, adjusted for 30-day VAD AE rate, demonstrated a non-significant mortality hazard ratio of 0.43 for < 30-days vs. ≥ 30-days group (95%CI 0.07-2.70, p = 0.37). In this era, there was no difference in survival based on VAD duration prior to HTx. This finding requires additional comparisons to the current era of VAD as a bridge to Tx.