Chinese herbal prescription Qing-Xin-Jie-Yu granule combined with conventional treatment for intermediate coronary lesions: study protocol for a randomized, double-blinded, placebo-controlled trial

Abstract Background Intermediate coronary lesion (ICL) is a critical stage affecting coronary artery disease’s progression and prognosis and may quickly progress to acute coronary syndrome. However, percutaneous coronary intervention therapy and conventional drug therapy have certain limitations. Qing-Xin-Jie-Yu Granules (QXJYG), a Chinese herbal prescription with a pre-research basis, has the potential to be a complementary treatment for ICL. Previous studies have shown that QXJYG combined with conventional drug therapy could alleviate angina symptoms and reduce the incidence of composite ‘hard’ endpoint in treating stable coronary artery disease. However, for ICL, the effect of this prescription on the degree of coronary stenosis, plaque stability, and long-term efficacy remains unclear. Therefore, we designed this study to evaluate the efficacy and safety of QXJYG in patients with ICL. Methods This is a multi-center, block-randomized, double-blinded, placebo-controlled trial. One hundred and twenty participants with ICL will be randomly assigned to two groups in a 1:1 ratio. Based on conventional intervention, the participants of the treatment group will receive QXJYG orally, and the participants of the control group will receive placebo for six successive months. The primary outcomes involve the degree of coronary stenosis, including the percentage of diameter stenosis and the percentage of area stenosis measured by coronary CT angiography. The secondary outcomes involve coronary artery calcification score, Gensini score, CT-fractional flow reserve, angina symptom score, traditional Chinese medicine syndrome score, blood lipids, inflammatory factors, carotid artery ultrasound parameters, and major adverse cardiovascular events. Safety will be assessed by adverse events and laboratory examinations. Measurements will be performed at baseline (visit 1), months 2 (visit 2), months 4 (visit 3), months 6 (visit 4), and months 12 (visit 5). Discussion The results of this trial will verify the efficacy and safety of QXJYG in treating ICL, thus adding to the existing knowledge for resolving the problem in ICL. Trial registration: This trial is registered at the Chinese Clinical Trial Registry (www.chictr.org.cn). Registration number: ChiCTR2200059262. Register date: April 27, 2022.