Perioperative mortality is the Achilles heel for cardiac transplantation in adults with congenital heart disease: Evidence from analysis of the UNOS registry.

BACKGROUND: Adults with congenital heart disease may present with end-stage heart failure necessitating orthotopic heart transplant (OHT). We sought to review the United Network for Organ Sharing (UNOS) experience with this unique cohort focusing on surgical outcomes and survival. METHODS: From the UNOS registry, 737 adult congenital heart disease recipients (ACHDR) out of 26,993 OHT patients (2.7%) who underwent OHT were studied to analyze early and late outcomes and compared to non-congenital recipients (NCR) over a 15-year period (2000-2014). RESULTS: More ACHDR underwent OHT in the recent-era (3.1%; 2010-2014) as compared to the initial-era (2.5%; 2000-2004; p = 0.03). ACHDR were more likely female (40% vs. 24%; p < 0.01), younger (35 vs. 53 years; p < 0.01), less likely to have ventricular assist devices (4.2% vs. 19.3%; p < 0.01), more likely to have class-II panel-reactive antibody >10%; p < 0.01, and were listed for a longer time (249 vs. 181 days; p < 0.01). When compared to the NCR in the same period, the ACHDR cohort had longer postoperative length of stay (27 vs. 20 days; p < 0.01), higher operative mortality (11.5% vs. 4.6% p < 0.001), higher incidence of primary graft dysfunction (4.3% vs. 2.6%; p < 0.01), and higher need for dialysis (20% vs. 9%; p < 0.01). Primary graft dysfunction is the most common cause of death in (5.8%) ACHDR. Although short-term survival is poorer, long-term survival of ACHDR was found to be equivalent or better than NCR in long term. CONCLUSIONS: Perioperative morbidity and mortality adversely affects short-term survival in ACHDR. ACHDR who survive the first post-transplant year have equivalent or better long-term survival than NCR.

Persistent strong anti-HLA antibody at high titer is complement binding and associated with increased risk of antibody-mediated rejection in heart transplant recipients.

BACKGROUND: Sensitized heart transplant candidates are evaluated for donor-specific anti-HLA IgG antibody (DSA) by Luminex single-antigen bead (SAB) testing (SAB-IgG) to determine donor suitability and help predict a positive complement-dependent cytotoxicity crossmatch (CDC-XM) by virtual crossmatching (VXM). However, SAB testing used for VXM does not correlate perfectly with CDC-XM results and individual transplant programs have center-specific permissible thresholds to predict crossmatch positivity. A novel Luminex SAB-based assay detecting C1q-binding HLA antibodies (SAB-C1q) contributes functional information to SAB testing, but the relationship between SAB strength and complement-binding ability is unclear. METHODS: In this retrospective study, we identified 15 pediatric and adult heart allograft candidates with calculated panel-reactive antibody (cPRA) >50% by SAB-IgG and compared conventional SAB-IgG results with SAB-C1q testing. RESULTS: Pre- and post-transplant DSA by SAB-C1q correlated with DSA by SAB-IgG and also with CDC-XM results and early post-transplant endomyocardial biopsy findings. Individual HLA antibodies by SAB-IgG in undiluted sera correlated poorly with SAB-C1q; however, when sera were diluted 1:16, SAB-IgG results were well correlated with SAB-C1q. In some sera, HLA antibodies with low mean fluorescent intensity (MFI) by SAB-IgG exhibited high SAB-C1q MFIs for the same HLA antigens. Diluting or heat-treating these sera increased SAB-IgG MFI, consistent with SAB-C1q results. In 13 recipients, SAB-C1q-positive DSA was associated with positive CDC-XM and with early clinical post-transplant antibody-mediated rejection (cAMR). CONCLUSIONS: Risk assessment for positive CDC-XM and early cAMR in sensitized heart allograft recipients are correlated with SAB-C1q reactivity.