004 Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation

To determine whether cardiovascular magnetic resonance (CMR)-based surveillance for cardiac allograft rejection in the first year after cardiac transplantation is safe compared to traditional endomyocardial biopsy (EMBx)-based surveillance. Forty orthotopic heart transplant recipients were randomly assigned at four weeks post-transplantation to a CMR- or EMBx-based screening program. CMR-based T1- and T2-mapping were used to grade cardiac allograft rejection. The safety of the two approaches was assessed at 52 weeks with respect to the endpoints of rejection, infection, hospitalisation, death, total immunosuppression dose, renal function and biopsy-related complications. A total of 238 CMRs and 11 EMBx were performed in the CMR group; 235 EMBx were performed in the EMBx group. Significant rejection occurred in similar numbers of patients in each group (CMR 7; EMBx 8); more hospitalisations ((HR 2.74; CI 1.71-4.41) p<0.001) and infections ((HR 2.39; CI 1.31-4.38), p=0.005) were observed in the EMBx group. Immunosuppression requirements were similar between groups. There was no difference in mortality with one patient dying in each group; likewise, renal function did not differ significantly between groups. There were 3 biopsy-related complications in the EMBx group. CMR-based surveillance for cardiac allograft rejection in the first year after cardiac transplantation is safe compared to traditional EMBx-based surveillance and effectively reduced the number of invasive EMBx procedures by ninety five percent over this period.