Notes from a recent visitor to Berlin: on myocarditis, effect of coronary angiography on thyroid function, and Virchow's inflammatory theory of atherosclerosis

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

BACKGROUND

Immunosuppressive treatment for myocarditis is controversial. Several small-scale randomized controlled trials (RCTs) reported inconsistent outcomes for patients with myocarditis.

METHODS

We 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.

RESULTS

Nine 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: -1.85 mm, 95% CI: -3.18 to -0.52 mm), but a long-term beneficial effect was not sustained (difference: -5.79 mm, 95% CI: -15.30 to 3.72 mm). 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).

CONCLUSION

Immunosuppressive 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.

Immunosuppressive therapy in acute myocarditis: an 18 year systematic review

BACKGROUND

Immunosuppressive therapy is reportedly ineffective in adults with acute myocarditis.

AIMS

To systematically review the impact of immunosuppressive therapy on the outcome of acute myocarditis in children.

METHODS

A literature search for articles published from 1984 to 2003 was conducted with the following keywords: myocarditis, dilated cardiomyopathy, and immunosuppression. The relevant studies were systematically reviewed and comparison of treatment effect was made by calculating the odds ratio (OR) and confidence interval (CI) using the exact method based on the exact discrete reference distribution.

RESULTS

Of the 1470 articles found, only nine studies were eligible. The odds for improvement with immunosuppression was between 4.33 (95% CI 0.52 to 52.23) and 2.7 (95% CI 0.59 to 14.21). Addition of a second immunosuppressive agent to prednisolone only proved effective in one randomised controlled trial (OR 0.09, 95% CI 0.01 to 0.52). Heterogeneity of these studies precluded pooled odds ratio.

CONCLUSION

Current data suggest that immunosuppressive therapy does not significantly improve outcomes in children with acute myocarditis and there is insufficient evidence for its routine use. However, statistical power to detect a significant difference in the treatment effect may be limited because of the small number of subjects. This, together with problems of diagnosis, varying treatment practices, and a relative lack of evidence based guidelines would support efforts for a large multicentre, randomised controlled trial to better define the role of immunosuppression in acute myocarditis.