Which of the following complications is currently the major limitation to the long-term success of cardiac transplantation?

Currently, graft aeriosclerosis (AKA graft vascular disease) is the most impoant limit to the long-term success of hea transplantation. For unknown reasons, the coronary aeries of transplanted heas undergo intimal thickening associated with hyperplasia of myocytes and fibroblasts and deposition of matrix. This results in luminal stenosis and myocardial ischemia. Patients may develop myocardial infarction, which is clinically silent because the hea is denervated. The overall survival after hea transplantation is 80% at 1 year and 60% at 5 years. Do not confuse graft aeriosclerosis with graft atherosclerosis. Atherosclerosis is caused by accumulation of cholesterol esters and development of atheromas. Atherosclerosis may recur in the coronary aeries of transplanted heas, but is not a limiting factor in long-term success of hea transplantation. Allograft rejection is ceainly a major postoperative problem. However, thanks to early diagnosis based on periodic endomyocardial biopsy and the availability of immunosuppressant therapy, this complication can be prevented or successfully treated. Although oppounistic infections and development of Epstein-Barr related lymphomas are undesired effects of profound immunosuppression, these complications do not constitute a significant limitation to the overall outcome of cardiac transplantation. Ref: Lin P.H., Kougias P., Bechara C., Cagiannos C., Huynh T.T., Chen C.J. (2010). Chapter 23. Aerial Disease. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwaz's Principles of Surgery, 9e.