Two-year incidence of the composite primary outcome was similar between gene profiling and biopsy. The 2-year cumulative rates of rejection with hemodynamic compromise, graft dysfunction from other causes, death, or retransplantation were similar in the gene profiling and biopsy group, fourteen-point-five percent versus fifteen-point-three percent. The study was designed to determine whether rejection monitoring with gene profiling was non-inferior to routine biopsies for the prevention of rejection with hemodynamic compromise, graft dysfunction, death, or retransplantation. The primary analysis was a comparison between the groups of the time to first occurrence of the composite outcome, using the hazard ratios calculated from a Cox proportional hazards model on the intention-to-treat (all randomized patients) population. Both the Kaplan-Meier method and Cox proportional hazard models were used to estimate event rates. The interaction effects of strategy group-by-center and strategy group-by-month post-transplantation at randomization were tested at an alpha level of zero-point-one-five. Eighty-seven percent of patients in the GEP arm had two or fewer EMBs per patient year. Fifty percent did not require an EMB during the study.