Immunosuppressive therapy for the control of life threatening ventricular arrhythmias in chronic myocarditis

Chronic myocarditis predisposes to the occurrence of spontaneous ventricular arrhythmias. It is not known if an immunosuppressive treatment - as a causal therapy - leads to arrhythmia suppression. In the present study, 12 patients (four female, eight male, mean age 53 +/- 15 years) with a mean left-ventricular ejection fraction of 52 +/- 19 % were included. After exclusion of coronary macroangiopathy, the presence of chronic myocarditis was demonstrated by immunohistological evaluation of right-ventricular biopsies taking the number of specific lymphocytes (CD 2-8), of activated macrophages and the degree of HLA-expression on interstitial and endothelial cells as a basis. Seven patients had a successful resuscitation due to ventricular fibrillation in their case history, three patients presented sustained monomorphic ventricular tachycardia and two syncopes with inducible tachyarrhythmias. As a ''conventional'' therapy ten patients received antiarrhythmic drugs and four patients an implantable cardioverter/defibrillator. After confirmation of the diagnosis by a second biopsy after 3 months, all patients underwent an immunosuppressive therapy with methylprednisolone. The initial dose of 1 mg/kg body weight was reduced by 20 mg each every 2 weeks, until a maintenance dosage of 8-12 mg/day was achieved. If the control study after 6 months still gave a positive result, a combined therapy with azathioprine, 100-150 mg/day, was carried out for a further 6 months. In nine patients (75 %), the control biopsy became negative, in three patients (25 %), the biopsy remained to be positive. In the group presenting negative bioposies no tachyarrhythmia relapse occurred within a follow-up period of 49 +/- 13 months, while in the group with positive biopsies, relapses occurred in two of three patients. Complete suppression during EPS after therapy was achieved in 50 % of the patients who were inducible before therapy. In addition to lymphocyte infiltration, particularly HLA expression on endothelial and interstitial cells was significantly reduced; left-ventricular ejection fraction was improved only in tendency, while left-ventricular filling pressure decreased significantly. In summary, in patients with chronic myocarditis and malignant ventricular arrhythmias, a high-dose immunosuppressive long-term therapy results in the significant reduction of inflammatory infiltrations in about 75 % of the cases and, at the same time, in the effective suppression of arrhythmias.