Traditional Chinese Medicine Shows Promise in Boosting Coronary Blood Flow for Angina Patients

• What happened: A phase IV trial found that Shexiang Tongxin Dropping Pill (STDP) significantly improved coronary blood flow in patients with coronary slow flow phenomenon (CSFP).
• Why it matters now: CSFP is linked to recurrent angina, reduced quality of life, and limited treatment options, making new therapies critical.
• What changes for people: Angina patients may benefit from improved coronary microvascular perfusion and reduced symptoms with a well-tolerated intervention.
• Who is affected: Cardiologists, angina patients, cardiovascular researchers, and healthcare providers seeking safer, effective treatments.

In a multicentre, randomized, controlled study, researchers investigated the effect of STDP in 200 adults diagnosed with angina and CSFP. The trial, conducted between July 2016 and August 2020, compared STDP to placebo, focusing on corrected TIMI frame count (CTFC), a key measure of coronary blood flow.

Significant Improvement in Coronary Flow

Patients receiving STDP showed notable reductions in CTFC in the left anterior descending artery and left circumflex artery (p<0.01), reflecting faster coronary perfusion. The placebo group did not show significant changes. Between-group differences were statistically significant for both arteries (p=0.008 for LAD, p=0.044 for LCX).

The therapy was well tolerated, with no major safety concerns, suggesting that STDP enhances coronary microvascular function while maintaining a strong safety profile.

Understanding CSFP and the Mechanism

CSFP occurs when blood flow through coronary arteries is delayed despite no obstructive disease, often due to microvascular dysfunction, endothelial impairment, and inflammation. Improving flow without increasing adverse effects may help reduce angina symptoms and improve daily functioning for affected patients.

Strengths, Limitations, and Next Steps

The trial benefited from a double-blind design and measured both angiographic outcomes and clinical symptoms over two months.

Limitations included baseline imbalances in high-density lipoprotein levels, limited quantification of angina symptoms, and a study population restricted to Chinese patients, highlighting the need for larger, diverse trials. Researchers recommend future studies with multivariable adjustments and refined symptom assessment tools to validate and expand on these findings.

Expert Insight

According to trial investigators, STDP could address an unmet clinical need in angina management by improving microvascular coronary perfusion safely, offering a potential adjunct to conventional therapies.