Six-month survival of DCD heart recipients stratified by selected risk factors. Unadjusted 6-month survival after heart transplant among recipients of DCD hearts as stratified by (A) total graft preservation time quartiles, (B) recipient age quartiles, (C) pretransplant ventricular assist device or total artificial heart use, and (D) total volume of DCD heart transplantation during study period at each center. VAD, Ventricular assist device; TAH, total artificial heart.