Background: Herbal medicines are used as 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 has yet to be established. This is an update of a review published in 2012.
Objectives: To assess the benefits and harms of herbal medicines on clinical (e.g. mortality, incidence of complications) and indirect outcomes (e.g. cardiac function, biochemical response) in patients with viral myocarditis, irrespective of the patients' age, gender or type (including acute and chronic viral myocarditis).
Search methods: We searched CENTRAL (2013, Issue 1) on The Cochrane Library, MEDLINE (Ovid, 1946 to January Week 4 2013), EMBASE (Ovid, 1980 to 2013 Week 04) and LILACS (Bireme) on 1 February 2013. We previously searched The 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) and the Cochrane Complementary Medicine Field Trials Register (June 2011). We handsearched Chinese journals and conference proceedings. No language restrictions were applied.
Selection criteria: Randomised controlled trials of herbal medicines (with a minimum duration of seven days of treatment) compared with placebo, no intervention, or conventional interventions were included. Trials of herbal medicine plus a conventional drug versus the drug alone were also included. We included only trials that reported an adequate description of allocation sequence generation.
Data collection and analysis: Two review authors independently extracted data and evaluated trial quality. Information on adverse effects was collected from the trial reports.
Main results: We did not identify any new trials with the updated search in February 2013. The 2011 update of this review included twenty randomised controlled trials involving 2177 people. All the 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 for random sequence generation, allocation concealment, selective reporting, and incomplete outcome data, we assessed the included trials as being at a high risk of bias. Thirteen different herbal medicines were tested in the included trials. One of the trials reported outcomes on mortality. The trials reported electrocardiogram results, levels of myocardial enzymes, cardiac function, and adverse effects.Compared with supportive therapy, Astragalus membranaceus injection did not show a significant reduction in the number of patients that died of cardiac failure.A meta-analysis showed a significant effect ofAstragalus membranaceus injection plus supportive therapy on the number of participants 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: Since no new trials were identified in the updated search in 2013, the conclusions remain the same as they were in 2012. There is no evidence of benefit of herbal medicine on all cause mortality. Some herbal medicines may lead to improvement of ventricular premature beat, electrocardiogram, levels of myocardial enzymes, and cardiac function in viral myocarditis. However, these findings should be interpreted with care, due to the 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 for viral myocarditis.