Immunosuppressive treatment in autoreactive myocarditis--results from a controlled trial

It is still a matter of controversy whether immunosuppressive therapy is beneficial in patients with acute myocarditis, although autoimmune mechanisms play an important role in the development of myocarditis and its sequelae, for example, in dilated heart muscle disease, particularly because it is postulated that in man immunosuppression may aggravate the viral cell damage that is proposed to trigger the myocarditis. We report the clinical (NYHA-class), haemodynamic (improvement of left ventricular ejection fraction, left ventricular end-diastolic volume index), histological (infiltrate, fibrosis, myocyte hypertrophy) and immunohistological (immunoglobulin and C3-binding) findings in a controlled study including 17 patients with active myocarditis or acute perimyocarditis who were treated with a combination of prednisone and azathioprine for 3 months. We compared them with 21 patients of comparable clinical and haemodynamic compromise who underwent conventional treatment. Follow-up examinations were performed after 3 months. There was significant improvement of ejection fraction and NYHA-classification under immunosuppressive treatment. Infiltrates were reduced significantly in the immunosuppressed patients group only. Binding of IgG and IgM in the endomyocardial biopsy was diminished slightly but not significantly by both regimens. Fibrosis and myocyte hypertrophy were augmented in both treatment arms. There was no difference with respect to prognosis: four patients died or underwent heart transplantation in the immunosuppressive treatment group compared to five conventionally treated patients.