Is danshen (Salvia miltiorrhiza) dripping pill more effective than isosorbide dinitrate in treating angina pectoris? A systematic review of randomized controlled trials

Background: Danshen dripping pill (DSP) is a popular Chinese medicinal product and often compared with isosorbide dinitrate (ISDN) in treating coronary heart disease angina pectoris. Over 100 randomized controlled trials (RCT) have been published in Chinese language but have not been evaluated according to the PRISMA systematic review standard. This study aims to provide a comprehensive and PRISMA-compliant systematic review with sensitivity and subgroup analyses.

Methods: RCTs published between 1994 and 2009 on DSP versus ISDN in treating angina pectoris for 4 or more weeks were retrieved from major databases, including PubMed, Chinese National Knowledge Infrastructure, and WanFang Data. Meta-analysis was performed on the overall effects on symptomatic and electrocardiography (ECG) improvements. Sensitivity analysis was conducted on the study quality of RCTs based on a refined Jadad scale and different efficacy definitions.

Results: Sixty RCTs with 6931 participants were included. Summary odds ratios for comparing DSP and ISDN were 2.49 (95% CI 2.03-3.05) by symptoms (n=60) and 2.14 (95% CI 1.82-2.52) by ECG (n=53) according to the basic efficacy definitions and were 1.67 (95% CI 1.45-1.91) by symptoms (n=56) and 1.75 (95% CI 1.51-2.04) by ECG (n=45) according to the stringent efficacy criteria.

Conclusion: The 60 eligible RCTs indicate that DSP is apparently more effective than ISDN in treating angina pectoris. However, further RCTs of larger scale, multi-centre/country, longer follow-up periods, and higher quality are still required to verify the efficacy of DSP over all anti-anginal therapies.