Induction with Rabbit-Thymoglobulin (r-ATG) is Associated with Lower Cardiac Allograft Vasculopathy (CAV)

Purpose CAV has an immunological component and continues to limit long term outcomes in heart transplantation (HT). Smaller single center studies have suggested that induction with r-ATG may reduce development of CAV. We evaluated the association of induction with r-ATG, Basiliximab (BxB), or ‘no induction’ and CAV in HT recipients, traditionally considered not highly sensitized [pre-transplant panel reactive antibody (PRA) class 1 and class 2 ≤ 10%]. Methods Between 6/2004 and 03/2015, we identified 4,654 adult HT recipients in UNOS who either had induction with r-ATG, BxB or ‘no induction’ at the time of HT, and had information on pre-HT PRA levels and CAV. Donor age above 55 years or structural abnormalities, multi-organ or repeat transplants were excluded. The 3 groups: r-ATG (n=644), BxB (n=991), no induction (n=3019) were compared for baseline donor/recipient characteristics and CAV. Results Overall, pre-transplant PRA 1 and 2 levels were 0.5±1.7% and 0.3±1.3% respectively. Compared to no induction or BxB, HT recipients in r-ATG group were slightly younger (53 vs 55 vs 56 yrs), more black race (23% vs 16% vs 22%), less Status 1A (49% vs 59 vs 62%). BxB group had more recipients with creatinine >1.5 (24% vs 23% in r-ARG vs 17% no-induction) (all p<0.05). The 3 groups were similar in ischemic etiology, pre-transplant PRA 1 and 2 levels, LVAD support and donor age. Compared to no induction, r-ATG induction group had lower CAV at 5 years [cox HR=0.87(0.76-0.99), p=0.03] and 10 years [0.88(0.78-0.97), 0.01] after adjusting for baseline differences (Figure 1). BxB group was associated with higher CAV when compared to no induction in adjusted Cox models. Survival was similar in the 3 groups. Conclusion Although rates of CAV were higher in our specific cohort than previously reported for the overall HT population, r-ATG was associated with lower CAV in HT recipients who are traditionally considered to be not highly sensitized. CAV has an immunological component and continues to limit long term outcomes in heart transplantation (HT). Smaller single center studies have suggested that induction with r-ATG may reduce development of CAV. We evaluated the association of induction with r-ATG, Basiliximab (BxB), or ‘no induction’ and CAV in HT recipients, traditionally considered not highly sensitized [pre-transplant panel reactive antibody (PRA) class 1 and class 2 ≤ 10%]. Between 6/2004 and 03/2015, we identified 4,654 adult HT recipients in UNOS who either had induction with r-ATG, BxB or ‘no induction’ at the time of HT, and had information on pre-HT PRA levels and CAV. Donor age above 55 years or structural abnormalities, multi-organ or repeat transplants were excluded. The 3 groups: r-ATG (n=644), BxB (n=991), no induction (n=3019) were compared for baseline donor/recipient characteristics and CAV. Overall, pre-transplant PRA 1 and 2 levels were 0.5±1.7% and 0.3±1.3% respectively. Compared to no induction or BxB, HT recipients in r-ATG group were slightly younger (53 vs 55 vs 56 yrs), more black race (23% vs 16% vs 22%), less Status 1A (49% vs 59 vs 62%). BxB group had more recipients with creatinine >1.5 (24% vs 23% in r-ARG vs 17% no-induction) (all p<0.05). The 3 groups were similar in ischemic etiology, pre-transplant PRA 1 and 2 levels, LVAD support and donor age. Compared to no induction, r-ATG induction group had lower CAV at 5 years [cox HR=0.87(0.76-0.99), p=0.03] and 10 years [0.88(0.78-0.97), 0.01] after adjusting for baseline differences (Figure 1). BxB group was associated with higher CAV when compared to no induction in adjusted Cox models. Survival was similar in the 3 groups. Although rates of CAV were higher in our specific cohort than previously reported for the overall HT population, r-ATG was associated with lower CAV in HT recipients who are traditionally considered to be not highly sensitized.