Pathology of cardiac transplantation: recipient hearts (chronic heart failure) and donor hearts (acute and chronic rejection).

Pathologic examination of both the recipient and the donor heart is critical to the success of cardiac transplantation. Idiopathic dilated cardiomyopathy and end-stage ischemic heart disease are still the most common diagnoses for which cardiac transplantation is performed in the United States. After transplantation, the donor heart is susceptible to immunologic (acute and chronic rejection), infectious, and ischemic injury. Other long-term changes, such as hypertrophy of the myocytes and interstitial fibrosis, may also affect the function of the transplanted heart. Periodic endomyocardial biopsies are important for monitoring the status of the transplanted heart. In patients treated with cyclosporine, the clinical signs of rejection may be minimal, and routine biopsy is the only means of detecting early rejection.