Background: Herbal medicines are being used for treating viral diseases including viral myocarditis, and many controlled trials have been done to investigate their efficacy.
Objectives: To assess the effects of herbal medicines on clinical and indirect outcomes in patients with viral myocarditis.
Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library 2003, Issue 3, MEDLINE (January 1966 to October 2003), EMBASE (January 1998 to October 2003), Chinese Biomedical Database (1979-2003), AMED (1985-2003), LILACS accessed in October 2003 and the trials register of the Cochrane Complementary Medicine Field. We handsearched Chinese journals and conference proceedings. No language or publication restrictions were used.
Selection criteria: Randomised controlled trials of herbal medicines (with a minimum of seven days treatment duration) compared with placebo, no intervention, or conventional interventions were included. Trials of herbal medicine plus conventional drug versus drug alone were also included.
Data collection and analysis: Two reviewers independently extracted data and evaluated trial quality. Study authors were contacted for additional information. Adverse effects information was collected from the trials.
Main results: Forty randomised trials, involving 3448 people were included. All trials were conducted and published in China, and the methodological quality was assessed as generally low. No trial had diagnosis of viral myocarditis confirmed histologically, and few trials attempted to establish viral aetiology for the myocarditis. Twenty-five different herbal medicines were tested in the included trials, which compared herbs with supportive therapy (17 trials), other controls (three trials), or treatment of herbs plus supportive therapy with supportive therapy alone (20 trials). The trials reported electrocardiogram, myocardial enzymes, cardiac function, symptoms, and adverse effects. Astragalus membranaceus (either as single herb or compound of herbs) showed significantly effects on improving arrhythmia, CPK levels, and cardiac function. Salviae miltiorrhizae injection showed significant effects on decreasing the arrhythmia and reducing LDH levels. Shenmai and Shengmai injection (Ginseng preparation) showed significantly effects on reducing myocardial enzymes and improving cardiac function. No serious adverse effect was reported.
Reviewers' conclusions: Some herbal medicines may have anti-arrhythmia effect in suspected viral myocarditis. However, interpretation of these findings should be careful due to the low methodological quality, small sample size, and limited number of trials on individual herbs. In the light of the findings, some herbal medicines deserve further examination in rigorous trials.