HLA sensitization in ventricular assist device recipients: Does type of device make a difference?

Background: We sought to (1) characterize the temporal pattern of T-cell panel reactive antibody during ventricular assist device support, (2) identify predictors of higher T-cell panel reactive antibody during ventricular assist device support, and (3) determine whether device type remained a predictor after accounting for nonrandom device selection. Methods: Between December 1991 and August 2000, 239 patients received implantable ventricular assist devices, of whom 231 had T-cell panel reactive antibody measured. Panel reactive antibody was measured before implantation of the assist device, approximately 2 weeks after device implantation, irregularly thereafter depending on clinical events and length of support, and at transplantation. Longitudinal mixed modeling was used to characterize the temporal pattern of sensitization and its predictors during ventricular assist device support. To account for nonrandom factors in device selection when comparing HeartMate (Thermo Cardiosystems, Inc, Woburn, Mass) and Novacor (Baxter Healthcare Corp, Novacor Div, Oakland, Calif) devices, we propensity-matched patients according to baseline characteristics. Results: T-cell panel reactive antibody increased rapidly after implantation of the ventricular assist device and then immediately began to decrease. Predictors of higher T-cell panel reactive antibody during support with the assist device were a shorter interval from device implantation to T-cell panel reactive antibody measurement (P < .0001), female sex (P = .0004), younger age (P =.01), higher T-cell panel reactive antibody before device implantation (P = .03), more perioperative red blood cell transfusions (P = .006), and an earlier date of device implantation (P =. 001). In matched patients, device type was not a predictor of higher T-cell panel reactive antibody during ventricular assist device support (P = .8). Conclusions: HLA sensitization during ventricular assist device support is not constant but increases rapidly at implantation and then decreases. This temporal pattern of sensitization is influenced by patient factors and not by the type of device.