Coronary heart disease (CHD) is one of the most common chronic cardiovascular conditions worldwide, posing a serious threat to human health and life expectancy (1). In recent years, the incidence and mortality rate of CHD have remained high, largely due to an aging population, lifestyle changes, and the accumulation of adverse environmental factors (2–5). The pathological basis of coronary heart disease is coronary atherosclerosis, which can lead to blood vessel narrowing or obstruction. This, in turn, triggers myocardial ischemia and hypoxia and, in severe cases, may lead to myocardial infarction, which can be life-threatening (6).

Percutaneous coronary intervention (PCI), as an effective treatment method, has emerged as a major breakthrough in the treatment of coronary heart disease due to its many advantages, such as minimal trauma, faster recovery, and rapid restoration of myocardial blood flow (7–9). A large number of clinical practices and studies have confirmed that PCI can significantly relieve angina symptoms, effectively reduce the incidence of acute myocardial infarction and other serious cardiovascular events, and greatly improve the quality of life of patients in the near future (10). However, post-PCI revascularization remains a critical problem, affecting the long-term prognosis and quality of life of patients (11, 12). Relevant studies have shown that drug-eluting stent (DES) in-stent restenosis (ISR) occurs in 3%–20% of patients (8, 11). The occurrence of in-stent restenosis (ISR) not only necessitates repeat interventions or surgical bypass surgery, which greatly increases healthcare costs and patient suffering, but also significantly reduces patient survival and quality of life (13).

Currently, conventional medicine mainly adopts comprehensive treatment strategies such as antiplatelet therapy, lipid regulation, and blood pressure and glucose control for the occurrence of ISR after PCI (14–16). Antiplatelet drugs, such as aspirin and clopidogrel, help reduce the risk of restenosis by inhibiting platelet aggregation and reducing thrombosis (14); additionally, statins, which are lipid-regulating agents, play a role in restenosis prevention by lowering lipid levels and stabilizing plaques (17, 18). However, these treatments have obvious limitations. For example, long-term use of antiplatelet drugs can lead to bleeding and other serious adverse reactions, and some patients may also develop drug resistance, which reduces the therapeutic efficacy (19).

In China, traditional Chinese medicine (TCM) is widely used for the prevention and treatment of cardiovascular diseases (20). In Chinese medicine, coronary artery disease belongs to the category of blood stasis syndrome, characterized byblood stasis, phlegm obstruction, qi deficiency, and cold condensation (20, 21). Post-PCI restenosis is thought to be caused by arterial and meridian damage resulting from qi deficiency, blood stasis, and cardiac meridian paralysis (22). Therefore, the principle of benefiting qi and activating blood has become a general treatment method for managing post-PCI restenosis (22, 23). In recent years, with the vigorous development of integrated Chinese and conventional medicine, the study of combining Chinese medicine with conventional medicine for the post-PCI treatment of coronary artery disease has gradually become a hotspot, which is expected to provide a new solution to reduce the rate of post-PCI restenosis and improve clinical outcomes for patients (20, 24).

Yiqi Huoxue Tongluo decoction (YHTD) originates from traditional Chinese medicine theory and has the main effects of benefiting qi, promoting blood circulation, and dredging the collaterals. Modern pharmacological studies have shown that qi-benefiting and blood-activating Chinese herbal compounds can exert anti-atherosclerotic effects by regulating blood lipids, inhibiting platelet activation, suppressing the expression of MCP-1 and NF-κB, and reducing the levels of inflammatory markers (25). Multiple studies have demonstrated that active components of Chinese herbs can improve vascular endothelial function by inhibiting the TLR4/NF-κB signaling pathway (26, 27). Based on this background, this study aims to systematically observe the effects of YHTD in combination with conventional medicine on restenosis rates and clinical efficacy in patients with coronary artery disease undergoing PCI to provide a more reliable basis and reference for clinical treatment.

Coronary heart disease is a common chronic cardiovascular condition and remains a serious threat to human health (35). Although PCI has brought a major breakthrough in the treatment of coronary heart disease, post-operative restenosis continues to affect the long-term prognosis of patients (36, 37). In this study, we compared the effects of conventional medicine treatment alone versus YHTD combined with conventional medicine on post-operative PCI patients with coronary artery disease, and the results showed that the combination therapy offered significant advantages in several aspects.

In terms of coronary restenosis, the observation group exhibited a significantly lower restenosis rate than the control group; additionally, the observation group showed increased values of MLD, NG, and NGI and decreased values of LLL and LLI. This suggests that YHTD combined with conventional medicine therapy can effectively inhibit endothelial proliferation, maintain vascular patency, and reduce the risk of restenosis (20, 38). From the perspective of Chinese medicine theory, coronary heart disease belongs to the category of blood stasis syndrome, characterized by blood stasis, phlegm obstruction, qi deficiency, and cold condensation; post-operative restenosis after PCI is believed to be associated with qi deficiency, blood stasis, and cardiac meridian paralysis (22). In YHTD, astragalus tonifies qi and elevates yang; danshen, chuanxiong, and safflower promote blood circulation and remove blood stasis; leech, dilong, and scorpion penetrate the channels to alleviate pain; and Glycyrrhiza tonifies the medicines to work together to activate qi and blood and penetrate the channels to alleviate pain (39, 40). Modern pharmacological studies have also confirmed that Chinese medicines with blood-activating and blood-stasis-eliminating properties exert effects such as antiplatelet aggregation, improvement of microcirculation, and inhibition of the proliferation of smooth muscle cells (40, 41). From the perspective of integrative medicine, the concept of qi deficiency in TCM corresponds to endothelial dysfunction and impaired energy metabolism at the cellular level, while blood stasis reflects the pathological states such as increased platelet aggregation, inflammation, and microcirculatory disturbances. Similarly, the meridian blockage concept aligns with vascular stenosis and impaired blood flow.

The therapeutic effects of YHTD can be attributed to its key bioactive components. Astragaloside IV, the main active component of astragalus, exhibits anti-inflammatory and endothelial protective effects by inhibiting the TLR4/NF-κB signaling pathway, thereby reducing the expression of inflammatory cytokines (IL-6, TNF-α) and adhesion molecules (VCAM-1, ICAM-1) while enhancing NO production (42). Tanshinone IIA protects against oxidative stress and inhibits the proliferation and migration of VSMCs, contributing to plaque stabilization (43). Tetramethylpyrazine exerts antiplatelet and anti-inflammatory effects via inhibition of the P38 MAPK and NF-κB signaling pathways (44). These components act synergistically to inhibit phenotypic transformation of VSMCs from a contractile to a synthetic state and suppress neointimal formation by downregulating PDGF and TLR4/NF-κB signaling pathways (45), which may explain the observed reductions in inflammatory markers (hs-CRP, Hcy, sST2) and the decreased restenosis rate in our study. Our findings are consistent with previous studies. For example, Mao et al. (40) reported a similar reduction in restenosis rates in post-PCI patients treated with Tongxinluo capsules. However, our study showed a more pronounced improvement in cardiac function parameters.

TCM, with its multi-component, multi-target, and holistic characteristics, plays an active and vital role in the prevention and treatment of various cardiovascular diseases in China, and it offers significant advantages in stabilizing the condition and improving the quality of life of patients (46). TCM has been recognized as a potential approach for relieving symptoms and improving quality of life in patients with cardiovascular disease (21). The SAQ is the most commonly used tool for assessing comprehensive and sensitive changes in the quality of life of cardiac patients (47). In this study, the TCM syndrome scores and SAQ scores improved after treatment; specifically, TCM syndrome scores of both groups decreased after treatment, with the observation group exhibiting lower scores than the control group; after 6 months of treatment, the scores of all SAQ dimensions increased in both groups, with the observation group exhibiting higher scores than the control group. These findings suggest that combination therapy effectively alleviates angina symptoms, improves TCM symptoms, and enhances the quality of life of patients (48, 49).

It has been reported that herbal formulas containing astragalus, or herbal astragalus alone, can enhance myocardial contractility and improve cardiac diastolic function (50, 51). In addition, shenmai injection may improve cardiac function in patients with chronic heart failure (CHF) through its anti-apoptotic effects, antioxidant activity, anti-inflammatory properties, and improvement of myocardial metabolism (52). Cardiac function indexes showed that LVEF and SV increased, while LVEDD and LVESD decreased in both groups after treatment, and the degree of improvement was better in the observation group than in the control group. These findings indicate that the combination therapy can effectively improve cardiac function and enhance myocardial contractility. This may be due to the synergistic effect of Chinese medicine and conventional medicine in improving myocardial blood perfusion and inhibiting myocardial remodeling, thus enhancing the pumping ability of the heart (53).

hs-CRP is a highly sensitive indicator of inflammatory response, and a decrease in its level reflects a reduction in the degree of inflammation in the body. Inflammation plays a key role in the development and progression of coronary artery disease, and elevated serum levels of hs-CRP have been significantly associated with the occurrence of restenosis (ISR) after coronary intervention (31, 54). In addition, studies have reported that homocysteine (Hcy) levels are positively correlated with the severity of restenosis after coronary intervention and can be used as an important biomarker for predicting the severity of restenosis (55, 56). Meanwhile, sST2 has been identified as an important indicator for assessing the prognosis of cardiovascular disease after PCI (34). The results of serum biomarker analysis showed that YHTD combined with conventional medicine therapies more effectively reduced the levels of hs-CRP, Hcy, and sST2, thus providing new ideas and methods for the post-PCI treatment of patients with coronary artery disease.

However, this study has some limitations. The relatively small sample size of only 80 patients may not comprehensively capture the diversity of patient characteristics, and there is a sampling error, so the representativeness and generalizability of the study results need to be improved. With a follow-up period of only 6 months, it is difficult to accurately assess the long-term efficacy and safety of interventions for post-PCI restenosis, which is a problem with a long-term dynamic process, because the observation period is relatively short. Additionally, this study used an open-label design in which patient blinding was not feasible; however, outcome assessors were blinded. The use of coronary angiography, instead of more sensitive techniques like IVUS or OCT, may have limited the accuracy of restenosis assessment. Future studies can be improved in the following aspects: by expanding the sample size and conducting multi-center, large-sample clinical studies to enhance the reliability and representativeness of the results; by extending the follow-up period to observe the long-term efficacy and safety of the combination therapy; and by incorporating advanced imaging techniques like IVUS or OCT to achieve a more accurate assessment of vascular changes.

Future research directions should include: (1) the application of multi-omics approaches to identify biomarkers predicting treatment response; (2) systematic investigations of specific bioactive compounds and their synergistic effects using network pharmacology; (3) mechanistic studies using advanced molecular techniques such as single-cell RNA sequencing to understand cell-specific responses; and (4) the development of standardized quality control methods for TCM preparations.

In conclusion, YHTD combined with conventional medicine therapy demonstrates significantly better outcomes than conventional medicine therapy alone in patients undergoing PCI for coronary artery disease; the combination therapy more effectively improves coronary restenosis, reduces TCM syndrome scores, alleviates angina symptoms, enhances cardiac function, and lowers the levels of related serum biomarkers. These findings suggest that YHTD may serve as an adjuvant therapy for post-PCI management. However, to further validate these results and establish its role in clinical practice, multi-center studies with larger sample sizes and advanced imaging techniques (IVUS/OCT) are needed.