(781) - Removal of Ventricular Assist Device at the Time of Heart Transplant in Sensitized Patients Results in Reduced Antibody Production

Abstract

Sensitized patients (pts) awaiting heart transplantation (HTx) are known to have increased risk of first year antibody-mediated rejection (AMR). In some studies sensitized pts with panel reactive antibody (PRA) > 25% also have increased mortality post-transplant. Pts with a left ventricular assist device (VAD) appear to be at higher risk for becoming sensitized due to blood transfusions. It has been observed that many sensitized VAD pts do well after HTx without developing AMR or increased mortality. It is postulated that the removal of the VAD at transplant might actually down-regulate the immune system so that a humoral response is dampened. We sought to review our sensitized VAD pts to assess their humoral response post-transplant. Between 2010-14 we assessed 74 VAD pts undergoing HTx. 19/74 VAD pts were sensitized (PRA>25%) and compared to sensitized non-VAD pts (n=55) for 1-year development of biopsy proven AMR, circulating antibodies, and survival. Only VAD pts with continuous flow devices were included. Due to the sensitized state, all pts received anti-thymocyte globulin (ATG) induction therapy. Sensitized VAD pts had a significant reduction in circulating antibodies over the first year after HTx compared to sensitized non-VAD pts. Specifically, there was a significant decrease in Class I Mean PRA % from baseline to 12-months post-transplant for the sensitized VAD group (57 ± 39% to 23. ± 32%, P=0.007). There was a trend for a reduction in Class II Mean PRA% in the sensitized VAD group. There was no significant difference in first-year AMR and survival in the sensitized VAD group compared to the sensitized non-VAD group. (table)Tabled 1EndpointsSensitized VAD (n=19)Sensitized Non-VAD (n=55)P-Value1-Year Survival94.7%94.5%0.9971-Year Freedom from Antibody-Mediated Rejection94.4%89.9%0.613Sensitized VAD (n=19)Baseline12-MonthsP-ValueClass I Mean PRA %56.63 ± 39.3923.09 ± 31.920.007Class II Mean PRA %37.94 ± 37.7018.18 ± 23.070.069Sensitized non-VAD (n=55)Class I Mean PRA %37.13 ± 33.7634.25 ± 34.600.660Class II Mean PRA %37.90 ± 32.9430.80 ± 35.940.283 Open table in a new tab Sensitized VAD pts appear to have their immune system affected by the presence of the device. Once the VAD is removed at transplant, there appears to be a down-regulation of the immune system as reflected by less development of circulating antibodies in the first year after HTx.