Morphology of graft arteriosclerosis in cardiac transplant recipients

The morphologic features of graft arteriosclerosis (GA) and other vascular lesions were semiquantitatively evaluated. Five failed cardiac allografts attributable to GA and five other allografts were obtained from nine autopsies and one surgical explanation. The subjects, aged 4.5 to 67 years, had a mean allograft survival of 735 +/- 184 days. A total of 1,174 arterial and 754 venous cross-sections were reviewed. Intimal fibrosis (nine cases, 254 arteries, and 118 veins), fibrofatty plaques (eight cases and 35 arteries), and cellular intima thickening and concentric foam cell lesions (eight cases, 326 arteries, and 20 veins) were seen. Cellular lesions contained T lymphocytes, monocytes, and cells of smooth muscle cell origin detected by staining using the immunoperoxidase technique. Allografts with severe GA had a greater luminal stenosis in epicardial arteries (P less than .05), greater cellular proliferation in large mural arterial lesions (P less than .004), and more foam cell lesions in both arteries (P less than .06) and veins (P less than .03) than other allografts. Medical fibrosis and thinning were present in six allografts. Severity of acute rejection (P less than .01) was correlated with the presence of GA. The morphology and distribution of GA is heterogeneous, with evidence supporting an immune-mediated pathogenesis.