ABSTRACT

C ardiac transplantation has become established as the treatment of choice for selected patients with advanced heart failure. The survival rate achieved with transplantation greatly exceeds that achieved with optimum medical therapy for this condition. Nevertheless, the long-term results of heart transplantation are far from perfect. The Registry of the International Society of Heart and Lung Transplantation (ISHLT) indicates that the overall patient half-time (time to 50% survival after transplantation) is only 8.7 years and the conditional half-life in those surviving beyond the first year is only 11.4 years.1 After the first year there is a con­ stant mortality rate of 4% a year. Although there was a substantial improvement in sur­ vival in the mid-1980s, further progress has been slow.1 The leading causes of death more than 1 year after transplantation are coronary artery disease, infection and malignancy.2 In one series, coronary artery disease accounted for about a quarter of deaths occurring 1-3 years after transplantation and the mortality rate had not improved with time;2 in another series, coronary disease caused the majority of late deaths.3 The angiographic incidence of coronary abnormalities increases steadily with time and, once angiographically appar­ ent, the disease may progress rapidly.3,4

The problem of coronary arterial disease in the allograft occurred in the first mediumterm survivor of human heart transplanta­ tion,5 and soon became recognized as a major

factor limiting the long term outcome of heart transplantation.6 The pathological character­ istics of the disease differ from spontaneous coronary atheroma and similar vascular lesions have been found in renal allografts.7,8 This Chapter provides an overview of this clinical problem as a framework for subse­ quent discussions of the mechanisms under­ lying the disease.