Adverse effects of interferon on the cardiovascular system in patients with chronic hepatitis C.

The therapeutic effects of interferon in chronic hepatitis C and many of its adverse effects have been well documented. However, there are only a few reports regarding its adverse effects on the cardiovascular system. The aim of this study was to clarify the clinical features of the adverse effects of interferon on the cardiovascular system in patients with chronic hepatitis C. We monitored 295 patients with chronic active hepatitis C during 312 courses of interferon therapy and for 1 year after the end of treatment for the presence of cardiovascular adverse effects. We found 6 patients with cardiovascular adverse effects during interferon therapy and 4 more patients within 1 year after the end of therapy (10/312, 3.2%). The adverse effects of interferon on the cardiovascular system included arrhythmia (n = 4), ischemic heart disease (n = 4) and myocardial disease (n = 2). None of the clinical factors, including history of cardiovascular disease, were related to these cardiovascular adverse effects. In all instances the patient's condition improved after discontinuation of interferon and adequate therapy. The cardiovascular adverse effects of interferon occurred frequently in patients with chronic hepatitis C, even after the end of therapy and they were unpredictable. Thus, all patients undergoing interferon therapy should be monitored not only during but also after the end of treatment.