Efficacy of Xuefu Zhuyu decoction compared with nitrates in treating angina pectoris: a meta-analysis of randomized controlled trials

Background: Xuefu Zhuyu decoction (XZD) is a popular Chinese medicinal formula and often compared with nitrates in treating coronary heart disease angina pectoris. This systematic review aims to evaluate the efficacy of XZD in treating angina pectoris according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) systematic review standard. Methods: Randomized controlled trials (RCTs) published from 1983 up to March 2014 on XZD versus nitrates in treating angina pectoris were retrieved from major databases, including Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), WanFang Data (WF), WeiPu Data (VIP), PubMed, Cochrane Library (CL), and Elsevier. No language restrictions were imposed. Meta-analysis was performed on the overall effects on the improvements of symptoms and electrocardiography (ECG). Risks of selection, performance, detection, attrition, reporting, and other bias were assessed by the Cochrane collaboration's tool for assessing risk of bias. Results: Twenty-two RCTs with 1951 participants were included. Summary risk ratios for comparing XZD and nitrates were 1.24 (95% CI 1.16-1.33) by symptoms (n=21) and 1.42 (95% CI 1.22-1.66) by ECG (n=16). Conclusion: Although a consistent result that XZD might be more effective than nitrates in treating angina pectoris is presented in this study, further RCTs of higher quality, larger scale, longer follow-up periods and multi-country are still required to identify the efficacy of XZD.