Early diagnosis of interferon-induced myocardial disorder in patients with chronic hepatitis C: evaluation by myocardial imaging with ¹²³I-BMIPP

Abstract:

Interferon (IFN) therapy for chronic hepatitis C is sometimes associated with cardiac complications. In the present study, we performed myocardial imaging with ¹²³I-labeled β-methyl-p-iodophenylpentadecanoic acid (¹²³I-BMIPP) in order to evaluate myocardial disorders caused by IFN. We studied 40 healthy subjects (H group) and 25 patients with chronic hepatitis C who had been treated with IFN (IFN group). A Holter electrocardiogram (ECG) was performed and the autonomic nervous function was assessed by analyzing the spectral variability and 1/f fluctuation of heart rate. Myocardial planner imaging with ¹²³I-BMIPP was performed to obtain the time activity curve for 20 min immediately after administration of ¹²³I-BMIPP (dynamic study). Early and delayed myocardial single photon emission computed tomography (SPECT) images were expressed as Bull's eyes and the myocardium was divided into four segments to calculate the washout rate for each segment on early and late SPECT images (early and late SPECT study). No significant differences in autonomic nervous function were observed between the two groups in heart rate variability. In a dynamic study, the reduction rate from the time activity curve was significantly higher in the IFN group compared with the H group (reduction rate, IFN group, 5.3 ± 3.7% vs H group, 1.2 ± 3.3%; P < 0.05). In the early and delayed myocardial SPECT study, the washout rate for the IFN group was significantly increased in all myocardial areas compared to that in the H group. However, the metabolic disorder of fatty acids caused by IFN was reversed on the se-cond ¹²³I-BMIPP myocardial scintigraphy examination several months after IFN therapy. These results indicate that metabolic disorders of fatty acids caused by IFN therapy can be detected before abnormalities are observed by Holter-ECG or echocardiography.