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-HLA 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 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 n=8, Intra-aortic balloon pump n= 2) listed for heart transplant. We found that seven out of eight (87.5%) patients supported with Impella developed AT1R-Ab, while the remaining one patient was borderline positive. The 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.