Immunosuppressive treatment for myocarditis: a meta-analysis of randomized controlled trials

BackgroundImmunosuppressive treatment for myocarditis is controversial. Several small-scale randomized controlled trials (RCTs) reported inconsistent outcomes for patients with myocarditis.MethodsWe searched on the Medline, Embase, and Cochrane databases for articles in English language between January 1966 and May 2013, as well as on the China National Knowledge Internet (CNKI, 1979 to May 2012) and the Chinese Biomedical Literature Database (CBM, 1978 to May 2013) for articles in Chinese language. Statistical analysis was performed using Review Manager 5.0.ResultsNine articles were finally selected, in which 342 patients were in immunosuppressive treatment group and 267 patients in conventional treatment group. The immunosuppressive treatment group showed a significant improvement in left ventricular ejection fraction at both short-term (3 months) [difference: 0.08, 95% confidence interval (CI): 0.05-0.10) and long-term (difference: 0.10, 95% CI: 0.00-0.21)] follow-up. Moreover, left ventricular end-diastolic dimension decreased significantly in the immunosuppressive treatment group after short-term follow-up (difference: -1.85mm, 95% CI: -3.18 to -0.52mm), but a long-term beneficial effect was not sustained (difference: -5.79mm, 95% CI: -15.30 to 3.72mm). There was no difference, however, between the two groups in the rate of death or heart transplantation (odds ratio: 1.33, 95% CI: 0.77, 2.31).ConclusionImmunosuppressive treatment might be beneficial for improving left ventricular systolic function and remodeling in patients with myocarditis, which could be considered as a therapeutic alternative when optimal conventional therapy is not effective. More large RCTs, however, are required.