The objective of this study is to determine whether early abnormalities of the heart arteries after heart transplantation can predict the development of CAV. We will use a combination of sophisticated imaging tools to examine in detail the early changes that occur in the arteries of a new heart. Heart transplant patients from the University of Ottawa Heart Institute and Toronto General Hospital will undergo a series of tests at 3 and 12 months after transplant. Statistical analyses will determine whether results from the above tests at 3 months predict the development of early CAV at 12 months after a heart transplant.