Detection of viral genome in the myocardium: Lack of prognostic and functional relevance in patients with acute dilated cardiomyopathy

Background The presence of viral genome in the myocardium of patients with dilated cardiomyopathy (DCM) has been suggested as causative for the underlying cardiac disease. Nevertheless, the results of present studies are conflicting regarding the natural course of heart diseases associated with detection of viral genome. This study was undertaken to determine if the detection of viral genome in the myocardium of patients with DCM is of functional and prognostic relevance under modern treatment strategies of heart insufficiency. Methods In 197 patients with DCM, left ventricular endomyocardial biopsies were performed. Analysis for genome of adenovirus, enterovirus (EV), and parvovirus B19 as well as enteroviral replication and immunohistology was performed. Results The increase in ejection fraction (EF) was 14.5 ± 12.4% in the EV-positive group compared with 11.1 ± 14.2 in the EV-negative group ( P = not significant [NS]) after a mean follow-up (FU) of 19.5 and 17.6 months. The increase in EF in the virus-positive group (positive for EV, adenovirus, or parvovirus B19) was 15.3 ± 13.3% compared with 12.3 ± 11.9% in the virus-negative group ( P = NS) after a mean FU of 17.6 and 11.5 months. There was no significant difference in the change of EF between the EV-positive and virus-negative groups. Detection of enteroviral RNA replication (detection of EV minus-strand RNA) did not result in a deterioration of left ventricular function compared with the virus-negative group ( P = NS) after mean FU of 11.2 and 12.0 months. The transplantation-free survival of the patients was not influenced by detection of viral genome. Conclusions Our results favor the view that the presence of viral genome in the myocardium of patients with DCM is of no functional and prognostic relevance.