Do Temporary Mechanical Circulatory Support Devices Activate Sensitization Pathways in Patients Awaiting Heart Transplantation?

Candidates for heart transplantation may be placed on durable left ventricular assist devices as bridge to transplantation. These patients are known to develop circulating antibodies mainly due to blood transfusion. It has been reported that up to 30-40% of these patients develop circulating antibodies which may limit the donor pool. It has not been established whether temporary mechanical circulatory support (tMCS) devices result in similar sensitization. Between 2016 and 2021, we assessed 16 patients waiting for heart transplantation who required temporary left ventricular support. tMCS included Impella (n=11) and IABP (n=5). Only patients who had no circulating antibodies at the time of tMCS were entered into this study. Blood samples were drawn beginning at 2 weeks following placement of the temporary device. Freedom from development of circulating antibodies was determined at 2-4 weeks following placement of tMCS. Only 1 of these 16 patients (6%) developed circulating antibodies just prior to heart transplantation while on tMCS. The mean time on tMCS devices prior to transplant was 22 days, and 10 of these 16 patients (63%) received packed red blood cells either during or after tMCS placement but prior to transplant. Patients placed on tMCS have a low likelihood of developing circulating antibodies despite receiving blood transfusions. tMCS does not appear to activate sensitization pathways. [ABSTRACT FROM AUTHOR]