Prognostic determinants in conventionally treated myocarditis and perimyocarditis--focus on antimyolemmal antibodies.

In this study from two specialized centres 85 patients with histologically proven myocarditis (n = 10) and clinically ascertained perimyocarditis (pericardial effusion and cardiomegaly or segmental wall motion abnormality; n = 75) were followed up for 4.5 + 1.9 years. Immunosuppressive treatment was not applied. After a mean follow-up period of 4.5 + 1.9 years 55% of patients had improved clinically and 35% of patients were completely free of symptoms. Relapses had occurred up to three times. Chronic forms were found in 20% of patients, mostly in those with pericarditis and effusions. Eighteen percent of the patients deteriorated gradually. In 20% of the chronic or deteriorating patients congestive heart failure developed (postmyocarditic heart muscle disease). Fifteen percent of the patients died, mainly from bacterial perimyocarditis and to a lesser extent from inflammatory heart disease from enteroviruses. Patients who succumbed after more than 6 months died either suddenly or from progressive heart failure. A favourable outcome was often accompanied by a decrease in titre, but this decrease was less impressive in those who had antimyolemmal and antisarcolemmal antibodies. The persistence of these antibodies in high titres predominated in patients with poor prognosis and postmyocarditic dilated heart muscle disease, as did cytolytic serum activity.