The aortic valve after heart transplantation

We studied the aortic root (wall, semilunar cusp, septal myocardium) in 37 patients (29 male and 8 female; mean age; 41 years) who died 2 to 4,380 days (mean, 398 days) after heart (n = 34) and heart-lung (n = 3) transplantation. The aim of the study was to assess tissue viability, graft-host biological interaction, and cusp mineralization with time. Study methods included gross inspection and photos of each specimen, microradiography, histology and immunohistochemistry, scanning and transmission electron microscopy, and atomic absorption spectroscopy. There were no cases of valve dysfunction; in particular, cusp tears or perforations never occurred. Only 1 valve, in place for 12 years, had a pin-point calcification visible to the naked eye. Optimal preservation of the tissue components (endothelium, fibroblasts, collagen and elastic fibers, proteoglycans, intrinsic nervous ganglia) was observed at both short and long term. Concomitant acute rejection of valve leaflets and myocardium was seen in 7, mild valve thickening in 14, myxoid degeneration in 4, and graft aortic atherosclerosis in 26. Mineralization was negligible and was not progressive with time. No linear correlation was found between mineralization and number of acute rejections. In conclusion, we observed optimal cusp viability and integrity even at long term, concomitant valve and myocardium rejection with no valvular sequelae, and negligible, non-progressive cusp calcification. Donor-recipient blood group matching, heart-beating donor, and chronic immunosuppression are the reasonable explanations of the optimal durability of the aortic valve after heart transplantation.