Were Traditional Chinese Medicine Injections Efficacious for Angina Pectoris? A Frequentist Network Meta-Analysis of Randomized Controlled Trials
Abstract Background: The efficacy of traditional Chinese medicine injections (TCMIs) for angina pectoris has never been well investigated for lacking quality assessment of evidence. This study aimed to conduct a comprehensive and rigorous network meta-analysis and assess the quality of evidence according to the Grading of Recommendations and Assessment, Development, and Evaluation (GRADE) approach to compare the efficacy of all TCMIs in treating angina pectoris.Methods: Following the protocol (reference: CRD42018117720), randomized controlled trials (RCTs) which compared one TCMI with another TCMI or conventional treatments on anginal outcome measures (i.e. symptomatic improvement, electrocardiography improvement, symptomatic recovery, and electrocardiography recovery) were included. The risk of bias among included RCTs was assessed with the revised Cochrane’s risk of bias tool 2. Frequentist statistical analyses including subgroup analysis, sensitivity analysis, meta-regression and publication bias analysis were performed. The certainty of evidence was assessed with the GRADE approach.Results: Totally, 475 RCTs including all 24 TCMIs were identified, while the quality of all but two included RCTs was poor. According to the network meta-analysis, Honghua (Safflower) injection were preferable both in improving symptoms and electrocardiography. However, significant inconsistency showed the intransitivity among indirect comparisons, results in network meta-analysis seemed thus not trustworthy. The quality of evidence was assessed as low or very low.Conclusions: The low-quality evidence reduced the confidence in the efficacious results. Current evidence hardly supports the beneficial effects of TCMIs in treating angina pectoris.