Efficacy and safety of Danlou tablets in the treatment of stable angina pectoris with intermingled phlegm and blood stasis syndrome in coronary heart disease: a multicenter randomized controlled study

Objectives: In this study, we assessed the clinical efficacy and safety of Danlou tablets in the treatment of stable angina pectoris (SAP) with intermingled phlegm and blood stasis (IPBS), to provide high-quality evidence-based medical evidence for the prevention and treatment of coronary heart disease.

Methods: In this multicenter randomized controlled study, 304 patients diagnosed with stable angina pectoris with IPBS enrolled from 12 national traditional Chinese medicine (TCM) clinical research centers in China were randomly assigned to the treatment group and the control group at a ratio of 1:1. Each group was divided into four subgroups based on the results of TCM syndrome differentiation: IPBS, IPBS combined with qi deficiency, IPBS combined with qi stagnation, and IPBS combined with toxin accumulation. The control group was treated with routine Western medicine. In addition to routine Western medicine treatment, the treatment group (the IPBS group) was treated with Danlou tablets or Danlou tablets supplemented by interventional therapies based on the results of traditional Chinese medicine differentiation. The frequency of angina attacks per week was the main efficacy evaluation indicator and the secondary efficacy evaluation indicators included angina symptom score, Seattle Angina Questionnaire, an electrocardiogram (ECG) efficacy evaluation, a cardiac Doppler two-dimensional ultrasound, an electrocardiogram treadmill exercise test, blood lipids, blood glucose, a coagulation function test, hemorheology indicators, homocysteine, C-reactive protein (CRP) or high sensitivity-CRP, TCM syndromes (syndrome score, tongue, pulse), and long-term prognosis (endpoint outcome, cardiovascular events).

Results: There were 300 cases in the full analysis set (FAS), 266 in the per-protocol set (PPS), and 300 in the safety set. Regarding the main efficacy indicator, after treatment, the reduction in the frequency of weekly angina attacks in the treatment group was significantly greater than that in the control group (P < 0.05). The results of the FAS and PPS were consistent. Regarding the secondary efficacy evaluation indicators, the angina symptom, TCM syndrome, ECG evaluation, Seattle Angina Pectoris Questionnaire, and 36-item Health Status Survey Summary Form scores of the treatment group were significantly higher than the control group (P < 0.05) and the homocysteine levels of the treatment group were significantly reduced (P < 0.05). The results of the FAS and PPS were consistent. In the PPS, the triglyceride levels in the treatment group were significantly lower than those in the control group after treatment (P < 0.05). The activated partial thromboplastin time in the treatment group decreased significantly (P < 0.05). There was no statistically significant difference in the safety indicators and incidence of adverse reactions between the two groups.

Conclusion: Treatment with Danlou tablets and the modified combination therapy based on Western medicine treatment could improve angina pectoris symptoms of patients with SAP and IPBS syndrome and its concurrent syndromes, and improve patients' quality of life. Furthermore, the treatment is safe, has a long-term prognosis, and is worth further promotion and application in clinical practice.

Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=39724, ChiCTR registry, ChiCTR1900023708.