Myocardial Inflammatory Infiltrate in the Hearts of Valve Donors
A Diaz, D Paredes, F Perez-Villa, A Vilarrodona, D Martinez, J Ramirez. Hospital Clinic, UB, Barcelona, Spain
Background: The histological evaluation of hearts used as valvular homograft is crucial to evaluate the donor's viability for heart valve homograft use, allowing the tissue bank to validate the graft. In the course of the routine evaluation of these hearts we observed by chance the appearance of unspecific inflammatory infiltrates, leading us to study a series of cases in order to establish their main characteristics, the differential diagnosis, its prevalence and relationship with the donor's main features.
Design: A prospective histological evaluation of 133 hearts accepted as valvular homograft was performed. In each case, five representative samples of myocardium were obtained, being the microscopic sections stained with H&E and examined for the presence, type (lymphocytes, neutrophils or both), density (graded semi quantitatively from 1+ to 4+, being the grade 4+ the case where the maximal density was observed) and extent of inflammatory cells (percentage of total area occupied by the infiltrate). The presence of myocyte necrosis foci was also evaluated and highlighted immunohistohemically with the antibody against C9. Donor's main characteristics were obtained in each case.
Results: Sixteen cases showed any type of inflammatory infiltrates not related to myocardial infarction or other known causes and most of them had lymphocytes as predominant cell type. In 7 cases the infiltrate was composed exclusively of lymphocytes, while in 2 there were neutrophils. The 7 remaining cases presented an admixture of lymphocytes and neutrophils. Myocardial inflammation was more frequently seen in brain death donors when compared to the other groups. When an echocardiography study was available, more than 80% of cases with inflammation showed myocardial dysfunction (very low ejection fraction and wall hypokinesia). Foci of myonecrosis were detected in 4 cases in association with lymphocytic infiltrates.
Conclusions: In the routine evaluation of hearts used as valvular homograft we can find inflammatory infiltrates in the myocardium, manly composed of lymphocytes and associated, in a minor proportion, with foci of myonecrosis. This finding should not be mistaken for a myocarditis, since this would preclude the use of the valvular homograft. Moreover, they could be the morphological expression of the well-recognized sympathetic storm secondary to the brain death situation.
Tuesday, March 10, 2009 1:00 PM
Poster Session IV # 54, Tuesday Afternoon