The invention provides novel methods of reducing transplant rejection and cardiacallograft vasculopathy in humans by employing the implantation of autologousprogenitor cells into the transplanted donor heart. The autologous progenitorcells can be vascular progenitor cells (VPCs) and/or myocyte progenitor cells(MPCs) isolated from the recipient's explanted heart. Alternatively,bone marrow progenitor cells (BMPCs) isolated from the recipient may also beused.