Relationship between bridging with ventricular assist device on rejection after heart transplantation

Background: Ventricular assist devices (VADs) are commonly used to bridge patients to heart transplantation. Recipients of VADs may develop anti-human histocompatibility leukocyte antigen antibodies, as reflected by elevated panel-reactive antibodies (PRA). The purpose of this study was to evaluate the relationship between bridging with VAD before heart transplantation and development of cellular rejection, humoral rejection, and allograft vasculopathy after transplantation. Methods: Data on all patients who underwent cardiac transplantation between July 1994 and February 2001 at Rush Presbyterian St Luke's Medical Center were retrospectively reviewed. Data collected included sex, age, etiology of cardiomyopathy, percentage panel reactive antibodies (by cytotoxic method), type and duration of mechanical circulatory support, transfusion history, rejection history (both cellular and humoral) after cardiac transplantation, and development of allograft vasculopathy. Cellular rejection was treated when International Society of Heart and Lung and Transplantation Grade 2 or greater in the first 12 months after transplant and Grade 3 or greater after 12 months and treated with intensification of immunosuppression. Humoral rejection was defined clinically as allograft dysfunction by echocardiography without evidence of cellular rejection on endomyocardial biopsy or allograft vasculopathy. Allograft vasculopathy was defined by presence of any degree of luminal narrowing or pruning of distal vessels by coronary arteriography. Statistical analyses were performed by chi-square test, Fisher's exact test, and Wilcoxon rank sum test, as appropriate. Results: Ninety-eight patients underwent cardiac transplantation during the study period (87 men, mean age 49 years, 46 ischemic etiology). Of these, 48 were bridged with HeartMate VAD (20 patients received vented electric device, 28 received pneumatic device). Nineteen percent of VAD patients had a peak pretransplant PRA ≥10% vs 2% of patients without VAD (p = 0.014). PRA ≥10%, use of VAD, or duration of VAD support did not predict development of humoral rejection. Use of VAD did not predict development of cellular rejection or allograft vasculopathy. VAD use was not associated with sudden death after heart transplantation. In the entire group of 98 patients, neither humoral nor cellular rejection predicted development of allograft vasculopathy. Longer ischemic time correlated with increased cellular rejection and humoral rejection after transplantation (p = 0.01). Conclusions: Some patients bridged to cardiac transplantation with VADs have increased PRA before heart transplantation, but this does not appear to translate into increased risk of either humoral or cellular rejection after transplantation or development of allograft vasculopathy as detected by coronary angiography.