Interferon and thymic hormones in the therapy of human myocarditis and idiopathic dilated cardiomyopathy

It is becoming increasingly apparent that idiopathic dilated cardiomyopathy (IDC) probably results from an acute viral myocarditis. One reasonable hypothesis is that persistent viral infection causes myocardial destruction leading to left ventricular dilatation and heart failure. The aim of this study was to evaluate the efficacy of interferon-alpha (IFN) and thymomodulin in the treatment of idiopathic myocarditis and IDC. Clinical, immunological, haemodynamic and histological evaluation was performed in 40 patients before inclusion in the study. Patients were randomized into three treatment groups: (a) conventional therapy plus IFN, (b) conventional therapy plus thymomodulin and (c) conventional therapy alone. Two-year follow-up included repeated endomyocardial biopsy, echocardiographic evaluation, treadmill exercise test, Holter monitoring study and radionuclide assessment of left ventricular function during exercise. Left ventricular ejection fraction increased during follow-up in most of the IFN-and thymomodulin-treated patients, and only in a few of conventionally treated patients. Left ventricular reserve was significantly higher at 2-year follow-up in patients treated with immunomodulators. No serious adverse effects were noticed during treatment. Our results suggest that treatment of myocarditis and/or IDC with IFN or thymomodulin induces an earlier and significantly superior clinical improvement than conventional therapy alone.