[Endomyocardial biopsy in heart transplantation: the experience of the Naples Center].

From January 1988 through August 1992, 38 cardiac transplants were performed. 385 endomyocardial biopsies (EMBs) from 32 cardiac allograft recipients were investigated. In 21 (5.45%) EMBs the specimens were inadequate for the diagnosis. In the remaining 364 EMBs the grades of acute rejection were: minimal in 213 (58.51%) EMBs, mild in 132 (36.26%), mild/moderate in 12 (3.3%) and moderate in 7 (1.93%). The most reliable histologic feature of acute rejection was the myocyte necrosis or damage in presence of pironinophilic mononuclear cell infiltrate, so our therapeutic protocol requires myocyte damage to perform an additional treatment, which was performed in 7 cases (1.93%). An intermediate grade mild/moderate, was introduced to classify the EMBs in which the myocyte necrosis was scant or not clear. In these patients another EMB was performed after 3 or 5 days. One patient died of chronic rejection 17 months after the transplant. Changes not related to acute rejection were: ischemic early or late necrosis; changes related to previous biopsy site; subendocardial infiltrate of mononuclear cells (Quilty's alteration); focal, diffuse or perimyocytic fibrosis and artefacts as contraction bands; nuclear or cytoplasmic vacuolar alterations. Some of these changes occasionally made the diagnosis hard or the specimens inadequate for the diagnosis. In spite of these diagnostic difficulties, the EMB is a safe and reliable invasive investigation which plays an important role in the management of rejection in cardiac allograft recipients.