Efficacy and safety of Suxiao Jiuxin Pill in the treatment of stable angina (Qi stagnation and blood stasis syndrome): study protocol of a randomized, double-blind, placebo-controlled, multi-center clinical trial

BACKGROUND: Coronary heart disease (CHD) has become one of the biggest health problems in the world. Stable angina is a common clinical type of CHD with poor prognosis and high mortality. Although there are various interventions for stable angina, none of them can significantly reduce mortality. Both basic and clinical research have shown that Suxiao Jiuxin Pill (SJP) can relieve the symptoms of angina pectoris and improve the clinical efficacy, but there is a lack of high-quality clinical research to provide research-based evidence. We design a randomized, double-blind, placebo-controlled trial to evaluate the efficacy of SJP for stable angina. METHODS/DESIGN: This is a prospective, randomized, double-blind, placebo-controlled, and multicenter trial. The trial will enroll 324 participants with chronic stable angina (Qi Stagnation and Blood Stasis syndrome). All participants will have received the conventional therapy of chronic stable angina. Participants will be randomized into two groups, conventional therapy plus SJP group and conventional therapy plus placebo group. Eligible participants will receive either SJP or placebo (five pills administered orally, three times daily) in addition to conventional treatment for 24 weeks. The primary outcomes are the symptom improvement rate of angina from baseline to 4 weeks after inclusion and major adverse cardiovascular events (MACE). The secondary outcomes are angina classification (CCS), improvement of traditional Chinese medicine (TCM) syndromes, Seattle Angina Scale score, the dosage of emergency drugs and the stopping rate, and electrocardiogram (EKG) efficacy. Adverse events will be monitored throughout the trial. DISCUSSION: Integrated traditional Chinese and Western Medicine is commonly used for angina in China. This study will evaluate the clinical effectiveness and safety of SJP for angina. The results of the trial will provide high-level clinical research-based evidence for the application of SJP instable angina. TRIAL REGISTRATION: This study protocol was registered on 14 March 2019. The registration number is ChiCTR1900021876 on the Chinese Clinical Trial Registry. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05448-6.