ABO Incompatible Transplantation: Great For Some But Not All
Kyle W. Riggs, Farhan Zafar, MD, Clifford Chin, MD, Chet R. Villa, MD, David L. S. Morales, MD.
Cincinnati Children's Hospital, Cincinnati, OH, USA.
Objectives: ABO incompatibility (ABOi) has been touted as a safe alternative to ABO compatible (ABOc) cardiac transplantation, particularly in infants. With excellent outcomes, its use has been expanding though we don’t know its implications on all groups of children being transplanted. Methods: The ISHLT database was searched for all children undergoing cardiac transplantation from 2000-2017. ABO compatibility status was classified as incompatible in recipients who had ABO antigens to the blood type of their donors. These patients were further grouped by era and diagnosis. ABOi survival was compared versus ABOc for cardiomyopathy and congenital heart disease (CHD) using Kaplan-Meier method with log-rank comparison. Results: There were 415 ABOi and 9,133 ABOc recipients. ABOi patients were more likely to have CHD (49.4%, n=205 vs 33.5%, n=2971; p<0.001) and were younger (<1 yr vs 8 yrs; p<0.001) compared to ABOc patients. For CHD infants since 2008, ABOi patients had worse post-transplant survival than ABOc patients (p=0.005); however, survival was similar for cardiomyopathy infants (p=0.294, Figure 1). Compared to ABOc infants with CHD, ABOi had similar creatinine and incidence of ECMO, VAD, mechanical ventilation, and inotropes at transplant, all p>0.500. Conclusions: ABOi transplantation appears to be an excellent option for cardiomyopathy patients; however, its use for CHD patients should be tempered until the cause of their worse survival compared to ABOc patients is further understood.