Hepatitis C virus and cardiomyopathy.

The importance of hepatitis C virus infection has been recently noted in patients with hypertrophic cardiomyopathy or dilated cardiomyopathy. In a collaborative research project of the Committees for the Study of Idiopathic Cardiomyopathy, hepatitis C virus antibody was found in 74 of 697 patients (10.6%) with hypertrophic cardiomyopathy and in 42 of 663 patients (6.3%) with dilated cardiomyopathy; these prevalences were significantly higher than that found in volunteer blood donors in Japan. Hepatitis C virus antibody was detected in 650 of 11,967 patients (5.4%) seeking care in 5 academic hospitals. Various cardiac abnormalities were found, and arrhythmias were the most frequent. These observations suggest that hepatitis C virus infection is an important cause of a variety of otherwise unexplained heart diseases. As a collaborative research with National Cardiovascular Center and Juntendo University, we tried to detect hepatitis C virus genomes using paraffin sections of autopsied hearts. Among 106 hearts examined, beta-actin gene was amplified in 61 hearts (52.6%). Among these, hepatitis C virus RNA was detected in 13 hearts (21.3%), and negative strands in 4 hearts (6.6%). Hepatitis C virus RNA was found in 6 hearts (26.0%) with hypertrophic cardiomyopathy, 3 hearts (11.5%) with dilated cardiomyopathy, 4 hearts (33.3%) with myocarditis. These hepatitis C virus RNA positive samples were obtained between 1979 and 1990, indicating that hepatitis C virus RNA can be amplified from paraffin-embedded hearts preserved for many years. More recently, we examined the effect of interferon on myocardial injury associated with active hepatitis C. As TL-201-SPECT was a more sensitive method to detect myocardial injury induced by hepatitis C virus than electrocardiography or echocardiography, we used TI-SPECT scores to evaluate the effect of interferon on myocardial injury. SPECT scores improved in 8 patients (53%) out of 15 patients in whom interferon therapy was completed. Circulating hepatitis C virus disappeared after interferon therapy in all 11 patients with improvement or no change, but hepatitis C virus genomes persisted in the blood in 2 aggravated patients. Although this study is preliminary, interferon therapy is a promising treatment for myocardial diseases caused by hepatitis C virus infection.