Comparative Efficacy and Safety of Mycophenolate Mofetil and Azathioprine in Combination with Corticosteroids in the Treatment of Lymphocytic Myocarditis

Aims: This paper aimed to study the efficacy and safety of mycophenolate mofetil (MM) in combination with corticosteroids in the treatment of lymphocytic myocarditis (LM) when compared to the standard combination of corticosteroids and azathioprine. Methods. The study included 50 adult patients (47.8 ± 10.8 y.o.) in a NYHA III functional class due to LM who were verified using endomyocardial biopsy. The main group included 29 patients who received MM at 2 g/day. The comparison group comprised 21 patients who received azathioprine at 150 [50; 150] mg/day. Both groups were administered with methylprednisolone. The average follow-up period was 30 [22; 35] months, but no less than 6 months. Results. The groups were comparable in the baseline parameters and standard drug therapy. In both groups, there was a comparable significant increase in the ejection fraction (from 30.6 ± 7.7% to 44.0 ± 9.4% vs. 29.2 ± 7.7% to 46.2 ± 11.8%, p < 0.001), and a decrease in systolic pressure in the pulmonary artery and the dimensions of the left ventricle and atrium. The frequency of death was two (6.9%) and two (9.5%), transplantation was one (3.4%) and one (4.8%) patient and the “death + transplantation” endpoint was three (10.3%) and three (14.3%) without differences between the groups. The presence of the parvovirus B19 in the myocardium in 6/5 patients did not affect the results. The incidence of infectious complications was comparable. The most severe infectious complications were pneumonia and fatal purulent encephalitis (both cases in the azathioprine group), leptospirosis meningitis (in the mycophenolate mofetil group). Conclusions. In the patients with LM, the combination of corticosteroids with MM at a dose of 2 g/day was at least no less effective than with azathioprine. There was a tendency toward a better tolerance using MM.