Abstract
BACKGROUND: Chinese herbal medicines (CHMs) are used for type 2 diabetes mellitus combined with stable angina pectoris (T2DM-SAP), but their long-term effects lack real-world evidence. OBJECTIVE: To evaluate the effects of additional CHMs on angina readmission rates compared to standard treatment alone in patients with T2DM-SAP. METHODS: This retrospective cohort study included 704 patients with T2DM-SAP. Participants were stratified into two groups based on cumulative CHMs use (≥ 3 months). The CHMs group included 115 patients, while the non-CHMs group included 589 patients. A 1:1 propensity score matching (PSM) was used to balance differences between groups. The primary outcome was angina readmission. The secondary outcomes were SAP readmission and unstable angina pectoris (UA) readmission. Kaplan-Meier survival curves were plotted before and after matching. Sensitivity analysis was performed using Cox proportional hazards model. Baseline prescriptions were collected and herbal frequency and efficacy were counted. RESULTS: After matching, there were 106 patients in each of the two groups. Before matching, compared with the non-CHMs group, the adjusted hazard ratio (aHR) of angina readmission in the CHMs group was 0.49 [95% confidence interval (CI): 0.34, 0.71, P<0.001]. After matching, the aHR was 0.37 [95% CI: 0.22, 0.60, P<0.001]. The reliability of the results was confirmed by sensitivity analyses adjusted for different covariates. The CHMs group demonstrated a significantly longer median time to angina readmission compared to the non-CHMs group (55.66 vs 13.90 months, P<0.001). Similar results were also shown after matching. 115 prescriptions involving 220 herbs were collected. CONCLUSION: Additional CHMs treatment can significantly reduce the incidence of angina readmission and prolongs the interval to recurrent events in T2DM-SAP patients.