Background: Herbal medicines are being used as a treatment for viral diseases such as viral myocarditis and numerous clinical trials have been conducted to investigate their efficacy. Despite this wealth of evidence, the role of herbal medicines in the treatment of viral myocarditis is yet to be established. This is an update of the review published in 2010.
Objectives: To assess the effects of herbal medicines on clinical (for example mortality, incidence of complications) and indirect outcomes (for example cardiac function, biochemical response) in patients with viral myocarditis.
Search methods: We searched CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE (January 1966 to June 2011), EMBASE (January 1998 to June 2011), Chinese Biomedical Database (1979 to 2011), China National Knowledge Infrastructure (1979 to 2011), Chinese VIP Information (1989 to 2011), Chinese Academic Conference Papers Database and Chinese Dissertation Database (1980 to 2011), AMED (June 2011), LILACS (June 2011), and the Cochrane Complementary Medicine Field Trials Register. We handsearched Chinese journals and conference proceedings. No language restrictions were applied.
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. Only trials that reported an adequate description of allocation sequence generation were included.
Data collection and analysis: Two review authors independently extracted data and evaluated trial quality. Adverse effects information was collected from the trials.
Main results: Twenty randomised controlled trials involving 2177 people were included. All trials were conducted and published in China. The controls included anti-arrhythmic drugs, corticosteroids, and antiviral therapies such as ribavirin or interferon. Combining the risk of bias on random sequence generation, allocation concealment, selective reporting, and incomplete outcome data, the included trials were assessed to be at high risk of bias. Thirteen different herbal medicines were tested in the included trials. None of the trials reported outcomes on mortality. The trials reported electrocardiogram results, level of myocardial enzymes, cardiac function, and adverse effects.A meta-analysis showed a significant effect of Astragalus membranaceus injection plus supportive therapy on the number of patients with an abnormal electrocardiogram (RR 0.28, 95% CI 0.13 to 0.61), ST-T changes (RR 0.72, 95% CI 0.54 to 0.95), creatine phosphate kinase (CPK) levels (MD -21.54, 95% CI -33.80 to -9.28), and lactate dehydrogenase (LDH) levels (MD -30.33, 95% CI -46.78 to -13.88).Shengmai injection plus supportive therapy showed a significant effect on the number of patients with an abnormal electrocardiogram (RR 0.11, 95% CI 0.01 to 0.86), CPK levels (MD -103.90, 95% CI -114.97 to -92.83), LDH levels (MD -34.60, 95% CI -51.25 to -17.95), and on myocardial enzyme CK-MB levels (MD -10.87, 95% CI -14.50 to -7.24). Shengmai decoction plus supportive therapy showed a significant effect on improving quality of life measured by the SF-36 (MD 40.20, 95% CI 18.13 to 62.27) compared to supportive therapy. Data on adverse events were only available from six of the included trials and no serious adverse effects were reported.
Authors' conclusions: Some herbal medicines may lead to improvement of ventricular premature beat, electrocardiogram, level of myocardial enzymes, and cardiac function in viral myocarditis. However, these findings should be interpreted with care due to the high risk of bias of the included studies, small sample size, and limited number of trials on individual herbs. Further robust trials are needed to explore the use of herbal medicines in viral myocarditis.