Histologic analysis of myocardial biopsies from donor hearts before transplantation.

Myocardial biopsy is an accepted diagnostic tool in the assessment of acute heart transplant rejection. An important element of this assessment is the so-called zero (0) biopsies. The purpose of the present study was histologic analysis and comparison of these biopsies. We examined biopsy specimens obtained from 35 hearts of donors aged 15-46 years. 0-1 biopsy was obtained during organ procurement and 0-2 biopsy immediately before coronary reperfusion after implantation. Histologic analysis of changes was carried out by two observers. 0 biopsies in 8 out of 35 cases were histologically normal. In 23 cases minute histologic changes were found. They included myocyte enlargement, perinuclear vacuolization, interstitial and perivascular edema and fibrosis. Sporadically (4 cases) we encountered also signs of cardiac myocyte damage (microfocal necrosis and/or myocyte disruption). Differences were seen both between individual donors as well as 0-1 and 0-2 biopsies obtained from the same donor. 0-1 and 0-2 biopsies differed more clearly in the appearance of interstitium and microvessels. Interstitial edema was more frequent in 0-2 than in 0-1 biopsy and it was usually more severe. Differences between 0-1 and 0-2 biopsies with respect to changes in cardiac myocytes and interstitium were as expected and may result from progress of changes due to hypoxia. In contrast, endothelial swelling was more frequent and more severe in 0-2 than in 0-1 biopsies. This phenomenon may be accounted for by easier penetration and greater effect of perfused preservation solutions on endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)