Study designs of evaluations included in the review
Randomised controlled trials (RCTs), case-controlled studies, non-controlled studies, retrospective studies and case series were eligible. Studies with fewer than 4 participants were excluded.
Specific interventions included in the review
Studies on immunosuppressive therapy were eligible for inclusion. The therapies in the included studies were prednisolone, azathioprine, cyclosporine A, intravenous immunoglobulin G, interferon-alpha and OKT3.
Participants included in the review
Studies on children (under 18 years of age) with acute myocarditis were eligible for inclusion. Studies on neonates were excluded, as were studies of mixed adult and child participants. The underlying aetiologies of myocarditis were not given in the included studies. Diagnosis was through endomyocardial biopsy (presence of inflammatory or lymphocytic infiltrates, or by the Dallas criteria), or clinically by the investigators, assessed within 2 months of presentation of symptoms. Clinical diagnostic symptoms included congestive heart failure (CHF), arrhythmias with no underlying structural abnormality, sudden unexplained cardiovascular collapse, or electrocardiographic (ECG) changes.
Outcomes assessed in the review
The outcomes of interest were survival and cardiovascular improvement. Survival included both being alive and not requiring a heart transplant. Markers of cardiovascular improvement were: resolution of symptoms of CHF or arrhythmia; resolution of arrhythmia on ECG; haemodynamic changes according to cardiac catheterisation, echocardiograph or radionuclide scan; decrease in, or an absence of inflammatory infiltrate in the myocardium on biopsy or 'healed' or 'resolved' according to the Dallas criteria. The mean duration of follow-up ranged from 8 to 59.4 months.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.