INHIBITION OF ACCELERATED CORONARY ATHEROSCLEROSIS WITH DEHYDROEPIANDROSTERONE IN THE HETEROTOPIC RABBIT MODEL OF CARDIAC TRANSPLANTATION

Background. Accelerated coronary atherosclerosis has become a critical problem in cardiac transplantation. Although the pathogenesis of this disease is unknown, hypercholesterolemia has been shown to be a major risk factor. Methods and Results. To study this problem, a hypercholesterolemic rabbit model of heterotopic cardiac transplantation was developed to study accelerated graft atherosclerosis. Based on suggestions in the literature, it was hypothesized that dehydroepiandrosterone (DHEA) may retard the progression of the disease. Using semiquantitative light microscopy, a predilection for the development of small vessel occlusive disease in the transplanted hearts was found. Chronic DHEA administration produced a 45% reduction in the number of significantly stenosed vessels in the transplanted hearts (p<0.05) compared with controls and a 62% reduction in the nontransplanted hearts (p<0.05), yielding an overall 50% reduction in the number of significantly stenosed vessels in both the transplanted and nontransplanted hearts. This reduction in luminal stenosis was observed in the absence of any significant alterations in lipid profiles. Conclusions. It is concluded that chronic DHEA administration in a hypercholesterolemic rabbit model of heterotopic cardiac transplantation significantly retards the progression of accelerated atherosclerosis in both the transplanted heart and in the native heart.