Histological features of endomyocardial biopsies in patients undergoing hemodialysis: Comparison with dilated cardiomyopathy and hypertensive heart disease

BACKGROUND: Heart failure is a frequently occurring complication in patients on maintenance hemodialysis (HD). However, the histological features of right ventricular endomyocardial biopsy (RVEMB) samples remain unclear. METHODS: The clinical characteristics and histological findings of consecutive patients undergoing HD with available RVEMB samples (HD group; n=28) were retrospectively compared with those of patients with dilated cardiomyopathy (n=56) and hypertensive heart disease (n=15). RESULTS: The mean myocyte diameter was significantly larger in the HD group than in the other groups (P<.001), whereas the mean percent area of fibrosis did not differ among the three groups. Immunohistochemical analysis revealed that the capillary density was significantly lower in the HD group compared with the other groups (P<.001), and it was positively associated with left ventricular ejection fraction (P=.014). The number of CD68-positive macrophages, which was significantly higher in the HD group compared with the other two groups (P<.001), was associated with cardiovascular mortality (P=.020; log-rank test). CONCLUSIONS: Myocyte hypertrophy, macrophage infiltration, and reduced capillary density were characteristic histological features of the RVEMB samples in patients undergoing HD, which may be related to the pathogenesis of cardiac dysfunction.