Endomyocardial biopsy analysis.
Biopsy specimens were taken with a dedicated bioptome (B-18110-S; 4.5 mm³, Mohnheim, Germany) advanced through various 7F or 8F coronary guiding catheters (JR4.0/AL1.0/JL4.0, Medtronic, Danvers, Mass). At least four biopsy specimens (median, n = 5) with a diameter of 1-3 mm were harvested under strictly sterile conditions. Two to three biopsy specimens were fixed in 4% buffered formaldehyde for hematoxylin and eosin, Masson’s trichrome, and Giemsa staining and performance of immunohistology. Another two to three cardiac tissue samples were quick-frozen or fixed in RNAlater (Ambion Inc, Foster City, Calif) for PCR detection of viral genomes without loss of sensitivity [16]. Biopsy specimens were investigated within 24 hours. Immunohistological staining and detection of viral genomes were performed as previously described [16,17].