Dilated Cardiomyopathy Associated With Hepatitis C Virus Infection

BACKGROUND: Myocarditis is thought to be commonly caused by various viruses, and accumulating evidence links viral myocarditis with the eventual development of dilated cardiomyopathy. In many cases, however, the evidence is only circumstantial, and direct conclusive proof is not available. Polymerase chain reaction (PCR) has been used to detect enterovirus RNA in myocardial tissue, but the wide discrepancy in results emphasizes the need for further study. METHODS AND RESULTS: We investigated hepatitis C virus infection in patients with dilated cardiomyopathy. The presence, type, and quantity of hepatitis C virus RNA were evaluated in the sera, and the presence of positive and negative strands of hepatitis C virus RNA in the heart was investigated with the PCR technique. Anti-hepatitis C virus antibody was present in the sera of 6 of 36 patients (16.7%) with dilated cardiomyopathy and in 1 of 40 patients (2.5%) with ischemic heart disease, showing a statistically significant (P < .05) difference. At an earlier time, acute myocarditis was suspected in 3 patients who had developed acute onset of heart failure, and the diagnosis was confirmed by endomyocardial biopsy in 1 patient. Hepatitis C virus RNA was present in the sera of 4 of the 6 patients, and all 4 had hepatitis C virus type II. The copy number of hepatitis C virus RNA in the serum was 8 x 10(2) to 2 x 10(3) genomes per 1 mL serum. Positive strands of hepatitis C virus were found in the hearts of 3 patients, and negative strands of hepatitis C virus were detected in the heart of 1 patient. CONCLUSIONS: The results suggest that hepatitis C virus infection is frequently found in patients with dilated cardiomyopathy and that hepatitis C virus is an important causal agent in the pathogenesis of the disease. Antiviral therapy against hepatitis C virus may be indicated in these patients.