Cardiac allograft remodeling (CAR), or changes in heart's geometric pattern, is one of the common complications after heart transplantation and often inflicts poor quality of life, heart failure, and decreased survival. The risk factors and mechanism for the development and progression of CAR are poorly defined, and there is no effective treatment for this condition. In the proposed study, we will identify the prevalence, risk factors, and effect of CAR on physical capacity, cardiac vascular disease, and patient survival after a heart transplant. For assessment of heart geometry, we will use cardiac magnetic resonance imaging (CMRI), a techniques used to visualize the internal structures of the body in detail. CMRI is considered as being a "gold standard" for evaluating the heart's structure and function. We will also evaluate the molecular and genetic markers associated with development and progression of CAR after heart transplantation.