Efficacy and safety of Shenqi Yangxin formula in patients with stable coronary artery disease based on CCTA: rationale, design, and study protocol for a randomized, double-blind, placebo-controlled study

Background Among patients with stable coronary artery disease (SCAD), those with moderate coronary artery stenosis remain at high risk for adverse cardiovascular events despite optimal medical therapy. Reducing residual cardiovascular risk, particularly inflammation-related risk, is a key target for improving long-term outcomes. Evaluation of plaque burden and hemodynamics in patients with SCAD based on coronary computed tomography angiography (CCTA)-derived techniques, along with risk stratification and prediction, has become a hotspot, holding significant importance for standardizing clinical management of SCAD. Shenqi Yangxin Formula (SYF), a traditional Chinese medicine compound, has been widely used in China for SCAD and shown to alleviate symptoms, but its mechanistic benefits remain unclear. Based on this, we proposed that SYF could benefit patients with SCAD (qi deficiency and blood stasis syndrome) by reducing residual cardiovascular risk and improving coronary hemodynamics. This clinical trial was designed to objectively evaluate the efficacy and safety of SYF in SCAD. Methods This is a randomized, double-blind, placebo-controlled trial, enrolling 60 SCAD patients meeting criteria for qi deficiency and blood stasis syndrome. Participants are randomized 1:1 to receive SYF or placebo in addition to guideline-directed medical therapy for 12 weeks at a loading dose, followed by 12 weeks at half dose. Results As of July 2024, enrollment is complete, with trial completion expected in the first quarter of 2026. The primary outcomes are changes in CCTA-derived coronary hemodynamic parameters (CT-derived fractional flow reserve, wall shear stress) and fat attenuation index at 24 weeks. Secondary outcomes include imaging characteristics of plaques, traditional chinese medicine syndrome scores, seattle angina questionnaire scores, echocardiography, adverse cardiovascular events, and metabolomic profiles. Participants undergo follow-up at 4, 12 and 24 weeks post-randomization. All data will be collected in case report forms and analyzed according to predefined statistical plans. Conclusion This study will provide novel evidence on the efficacy and safety of SYF in improving coronary hemodynamics and reducing residual inflammatory risk in patients with SCAD and moderate stenosis, potentially offering a complementary therapeutic strategy. Clinical Trial Registration http://123.57.9.4:8085/zh-CN/Home/ProjectView?pid=dbc777bb-434e-44a4-af75-cfabc32d64db , identifier ITMCTR2024000215.