ENDOCARDIAL INFILTRATES IN THE TRANSPLANTED HEART - CLINICAL-SIGNIFICANCE EMERGING FROM THE ANALYSIS OF 5026 ENDOMYOCARDIAL BIOPSY SPECIMENS

To further elucidate the significance of endocardial infiltrates in he art transplant patients, the presence, frequency, and type of endocard ial infiltrates were evaluated in 5026 endomyocardial biopsy specimens obtained from 200 heart transplant patients 0 to 75 months after hear t transplantation. The relationship of endocardial infiltrates to immu nologic, clinical, and demographic variables was then explored. Endoca rdial infiltrates were detected in 557 endomyocardial biopsy specimens (11%) from 117 heart transplant patients (58%) at 6.3 +/- 9.4 months (x +/- SD; range, 0 to 49 months) after heart transplantation. Heart t ransplant patients with endocardial infiltrates were younger (p = 0.03 ), had a greater incidence of idiopathic dilated cardiomyopathy before heart transplantation (p = 0.05), and included a greater percentage o f females (p < 0.05). Both total and treated rejection rates were sign ificantly higher in patients with endocardial infiltrates versus those without endocardial infiltrates (p = 0.0001). Rejection on the subseq uent endomyocardial biopsies was more often present in endocardial bio psy specimens with endocardial infiltrates than in those without endoc ardial infiltrates, both in the presence (37% versus 24%; p < 0.001) a nd absence (33% versus 19%; p < 0.0001) of concomitant findings of rej ection. No association was identified between endocardial infiltrates and posttransplantation lymphoproliferative disorder, cytomegalovirus infection, Epstein-Barr virus infection, or cardiac allograft vasculop athy. Multivariate regression analysis confirmed that the occurrence o f endocardial infiltrates is associated with rejection when adjustment is made for patient's age, gender, heart disease before transplantati on, follow-up time, and number of endomyocardial biopsies after heart transplantation (p = 0.0001). Conclusions: (1) Endocardial infiltrates may occur with or without associated endomyocardial biopsy findings o f rejection. (2) The highly significant association between endocardia l infiltrates and endomyocardial biopsy findings of rejection suggests that endocardial infiltrates may be a manifestation of rejection. (3) The higher frequency of endocardial infiltrates in younger and female heart transplant patients, groups that are known to be at higher risk for rejection, lends further support to this hypothesis. (4) Because endocardial infiltrates, even in the absence of endomyocardial biopsy findings of rejection, predict subsequent rejection, large-scale prosp ective studies are needed to determine whether the finding of endocard ial infiltrates on endomyocardial biopsy warrants closer rejection sur veillance or intensification of immunosuppression.