Development of angiotensin II type 1 receptor antibodies in patients with temporary mechanical circulatory support.

Angiotensin II type 1 receptor antibodies (AT1R-Ab) are among the most investigated type of non-human leukocyte antigen antibodies in solid organ transplantation, particularly given its association with allograft dysfunction. Some prior studies have described the development of AT1R antibodies in patients with durable mechanical circulatory support (MCS); however, the role of temporary MCS in autoantibody development is still uncertain. Given that the current United Network For Organ Sharing (UNOS) allocation system prioritizes heart transplant recipients in cardiogenic shock requiring temporary MCS, we investigated the development of these antibodies in 10 patients with temporary MCS (Impella 5.5  = 8, Intra-aortic balloon pump  = 2) listed for heart transplant. We found that 7 out of 8 (87.5%) patients supported with Impella developed AT1R-Ab, while the remaining 1 patient was borderline positive. Two patients supported with an intra-aortic balloon pump did not develop AT1R-Ab. We attribute this difference to the endothelial shear stress imparted by Impella devices, although more investigation is needed.