64th ACNP Annual Meeting

Nassau, Bahamas | Jan 2026

Traditional Chinese Medicine Improves Coronary Blood Flow in Angina Patients

Coronary slow flow phenomenon (CSFP) in patients with angina was significantly improved with Shexiang Tongxin Dropping Pill (STDP), according to new phase IV trial data presented at the ACNP Meeting. This supports its efficacy and safety in routine clinical practice.

CSFP is characterised by delayed coronary blood flow in the absence of obstructive coronary artery disease. It is associated with recurrent angina, impaired quality of life, and increased healthcare use. Effective pharmacological strategies remain a key unmet need in cardiovascular care.

Phase IV Clinical Study Analysis

In this multicentre, randomised, controlled study, investigators evaluated the efficacy and safety of STDP in 200 adults with angina and CSFP. Participants were enrolled between July 2016 and August 2020 and randomly assigned to receive STDP or placebo. The primary outcome was change in corrected TIMI frame count (CTFC), an angiographic measure of coronary blood flow.

p < 0.01 CTFC Reduction

p = 0.008 LAD Artery Flow

100% Well Tolerated

The results showed that patients receiving the STDP experienced significant reductions in CTFC in both the left anterior descending artery and left circumflex artery (both p<0.01), indicating faster coronary flow. No significant changes were observed in the placebo group. Between-group differences were significant for both the left anterior descending artery (p=0.008) and left circumflex artery (p=0.044).

Mechanism of Action: CSFP involves microvascular dysfunction, endothelial impairment, and inflammation. By improving coronary blood flow without increasing adverse events, STDP addresses the key mechanisms underlying angina symptoms.

Strengths, Limitations, and Future Directions

The trial’s strengths included its randomised, double-blind design and assessment of both angiographic coronary flow and clinical measures, including angina symptoms and electrocardiographic parameters, over two months of treatment.

Critical Observations

The authors highlighted a baseline imbalance in high-density lipoprotein levels between groups, which may have influenced outcomes. They recommended larger studies with multivariable lipid adjustment to clarify the independent effects of STDP.

Limitations also included imprecise angina symptom quantification at enrolment and a study population limited to Chinese patients, supporting the need for refined symptom tools and validation in more diverse cohorts. Nevertheless, these data positioned STDP as a promising option for angina patients with CSFP.