[Immunosuppressive therapy in myocarditis and dilated cardiomyopathy--a critical analysis]

Clinical and experimental examinations suggest that autoimmunological mechanisms may play an important role in the pathogenesis of postmyocarditic cardiomyopathy. These may be due to the viral infection itself or may be induced by the viral persistence. Following these ideas an immunosuppressive therapy to prevent the progression of myocarditis to dilative cardiomyopathy is discussed. Since the introduction of endomyocardial biopsies in the diagnosis of myocarditis several papers reported trials of an immunosuppressive therapy in histologically proven myocarditis. But all of these studies were not randomized and only a limited number of patients were treated. Both the primary diagnosis, "myocarditis", as well as the histological findings to evaluate the course of the disease are not well defined and therefore were used differently in the studies published so far. Moreover, the regimens used for immunosuppressive therapy until now were not standardized, thus making it impossible to compare the various studies. Another important problem is the often observed spontaneous remission of histologically proven myocarditis. It may be that it is due to these factors that the results published so far report quite different success rates for the immunosuppressive therapy in myocarditis. Recent scientific findings indicate that the combination of virological, histological, immunohistological and immunological examinations will allow a marked improvement in the finding of the diagnosis and the further control of the course of myocarditis in the near future. But as long as no significant results about the clinical advantage of immunosuppressive therapy in myocarditis exist a general use of immunosuppressive therapy should be avoided. It is to be hoped that the doubleblind-randomized multicenter studies now in progress will provide definite results about the use of immunosuppressive therapy in myocarditis.