Lack of objective improvement in ventricular systolic function in patients with myocarditis treated with azathioprine and prednisone

Six patients with myocarditis documented by biopsy, after a baseline right heart catheterization and echocardiogram, underwent treatment with azathioprine and prednisone. After 3 months of treatment, biopsy, right heart catheterization and echocardiogram were repeated. In addition to the immunosuppressive therapy, most patients received additional conventional medications for heart failure between evaluation periods (mean number of cardiac drugs increased from 1.7 +/- 1.0 to 2.7 +/- 0.05, p = 0.041). Mean heart rate decreased (105 +/- 14 to 84 +/- 13 beats/min, p = 0.016), as did pulmonary wedge pressure (23 +/- 8 to 12 +/- 4 mm Hg, p = 0.012). There were no significant changes in cardiac index (3.1 +/- 0.8 to 2.9 +/- 1.0 liters/min), end-diastolic dimension (62 +/- 13 to 62 +/- 12 mm) or fractional shortening (11 +/- 6 to 12 +/- 3%) with treatment. Complications from immunosuppressive therapy included severe soft tissue infection, acute psychosis and adrenal insufficiency in one patient each. The benefits from prednisone and azathioprine in this group of patients have not been demonstrated. Although heart rate and pulmonary wedge pressure decreased, these changes could be ascribed to increases in the conventional therapy for heart failure. Finally, there is a high incidence of side effects from prednisone and azathioprine therapy. These findings suggest that this unproven therapy for myocarditis should be limited to experimental protocols.