Could ginseng-based medicines be better than nitrates in treating ischemic heart disease? A systematic review and meta-analysis of randomized controlled trials

Background: Ginseng-based medicines and nitrates are commonly used in treating ischemic heart disease (IHD) angina pectoris in China. Hundreds of randomized controlled trials (RCTs) reported in Chinese language claimed that ginseng-based medicines can relieve the symptoms of IHD. This study provides the first PRISMA-compliant systematic review with sensitivity and subgroup analyses to evaluate the RCTs comparing the efficacies of ginseng-based medicines and nitrates in treating ischemic heart disease, particularly angina pectoris. Methods: Past RCTs published up to 2010 on ginseng versus nitrates in treating IHD for 14 or more days were retrieved from major English and Chinese databases, including PubMed, Science Direct, Cochrane Library, WangFang Data, and Chinese National Knowledge Infrastructure. The qualities of included RCTs were assessed with Jadad scale, a refined Jadad scale called M scale, CONSORT 2010 checklist, and Cochrane risk of bias tool. Meta-analysis was performed on the primary outcomes including the improvement of symptoms and electrocardiography (ECG). Subgroup analysis, sensitivity analysis, and meta-regression were performed to evaluate the effects of study characteristics of RCTs, including quality, follow-up periods, and efficacy definitions on the overall effect size of ginseng. Results: Eighteen RCTs with 1549 participants were included. Overall odds ratios for comparing ginseng-based medicines with nitrates were 3.00 (95% Cl: 2.27-3.96) in symptom improvement (n = 18) and 1.61(95% CI: 1.20-2.15) in ECG improvement (n = 10). Subgroup analysis, sensitivity analysis, and meta-regression found no significant difference in overall effects among all study characteristics, indicating that the overall effects were stable. Conclusion: The meta-analysis of 18 eligible RCTs demonstrates moderate evidence that ginseng is more effective than nitrates for treating angina pectoris. However, further RCTs for higher quality, longer follow-up periods, lager sample size, multi-center/country, and are still required to verify the efficacy. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.