THE MYOCARDITIS TREATMENT TRIAL - DESIGN, METHODS AND PATIENT ENROLLMENT

The Myocarditis Treatment Trial was a multicentre clinical trial condu cted to determine the efficacy of immunosuppressive therapy for treatm ent of biopsy-documented myocarditis, and to improve understanding of the immunological mechanisms in the development of myocarditis. Thirty -one centres screened 2305 patients with unexplained heart failure, an d 2233 patients underwent an endomyocardial biopsy which provided adeq uate tissue for diagnosis. Those with a positive biopsy and a left ven tricular ejection function (LVEF) less than 45% were randomly assigned to receive immunosuppressive therapy plus conventional drug therapy f or congestive heart failure (66 patients) or conventional therapy only (45 patients) for 24 weeks. For 28 additional weeks all patients rece ived conventional therapy only. In addition to diagnostic and clinical data, serum and myocardial tissue for immunological marker analysis a nd histopathologic evaluation were collected at baseline and at 12, 28 and 52 weeks after randomization. The primary analysis of efficacy wa s designed as a comparison of the mean increase in LVEF al week 28 bet ween treatment limbs. Secondary objectives were to evaluate survival d ifferences, and changes in the histopathology of the disease and immun ological markers. Randomized patients were relatively young (mean age, 42.0 years +/- 13.8 standard deviation (sd)) and entered the Trial wi th a mean LVEF percent of 24.3 +/- 10.1 sd) and mean exercise treadmil l duration of 9.4 (+/- 5.3 sd) minutes. The incidence of biopsy-docume nted myocarditis was low (9.6%). The analyses of outcome and immunolog ical data are reported elsewhere.