Purpose: Non-HLA antibodies (NHAb) are increasingly being investigated for their potential role in graft complications. Consensus on which NHAb to test and with what frequency varies between centers. This multi-center collaboration aims to develop a sample testing strategy to aid centers who wish to incorporate NHAb testing into practice.

Conclusion: ACHD transplant patients were younger and more likely to be female than other recipients.They spent longer on the waitlist, and had worse 1 year survival but better long term survival.Timing and specialised management of these young but complex patients may potentially further improve post-transplant survival.

Allomap scores in children and adolescents can be used to successfully predict absence of rejection with NPVs between 98%-100%; scores less than or equal to 32 correlated 100% with biopsy grades of 0-1R in this population. Given these results, we speculate that Allomap use will lead to a reduced need for cardiac catheterization and biopsy in this population but further studies in a larger pediatric transplant population is warranted.

An overall outcome of children bridged to heart transplant (HT) with VAD at the time of transplant is associated with superior post-transplant survival than ECMO support. Limited outcomes information is available on mechanical circulatory support device (MCSD) in patients with single ventricle (SV). We analyzed data from the Pediatric Heart Transplant Study (PHTS) registry to evaluate the outcome of children with SV physiology who are supported with MCSD as a bridge to HT and their post-HT outcomes. Of the 3631 PHTS patients listed for HT between 2005 and 2014, 1825 (50%) had congenital heart disease (CHD) [SV= 1381 (76%) and biventricular (Bi-V) = 444 (24%)]. Of these, 906 (65%) SV patients and 298 (67%) Bi-V underwent HT; 233 (17%) and 80 (18%) died while waiting. 57% of all SV patients had hypoplastic left heart syndrome. MCSD support was more prevalent in Bi-V patients (46%: 24% ECMO & 22% VAD) compared to SV (14%: 9% ECMO & 5% VAD) (p<.01). Overall, 40% of SV patients (45.3% of VAD group & 38.6% of ECMO group) with MCSD received transplantation by 6 months compared to 59% of those without MCSD. SV waitlist mortality was 11% among no-MCSD support, 35% in VAD group, and 47% in ECMO group at 6 months (p <.01). SV patients on MCSD were more likely to remain on support until HT if they received VAD 22/60 (36%) compared to ECMO 10/127 (8%); p<.01. After HT, 12 month survival was significantly different between SV groups with no MCSD at listing or while listed (88%), VAD (78%) and ECMO (69%); p<.01. However, there was no difference in survival between SV patients on VAD at the time of HT (74%) vs those on ECMO (80%); p=0.9 (figure). Waitlist mortality for SV patients supported with MCSD remains unacceptably high. SV patients receiving MCSD are more likely to stay on support until HT if they had VAD compared to ECMO. However, for those SV patients on MCSD support at HT, there was no significant difference in survival outcomes between ECMO and VAD.