Atherosclerosis-related diseases such as ischemic heart diseases and strokes have a high morbidity and mortality rate as well as a poor prognosis (Libby, 2021), putting a heavy physical and financial burden on patients (Humphries et al., 2018). Atherosclerosis (AS), as a high-risk factor and a major pathological basis for cardiovascular and cerebrovascular events (Prandoni et al., 2017), has become more prominent in modern decades as people’s living standards have enhanced, and the prevalence is expected to rise by 18% by 2030 (Valanti et al., 2021). AS is commonly classified as Carotid atherosclerosis sclerosis (CAS), Coronary atherosclerosis, lower limb atherosclerosis, and so on, depending on the location of the lesion. The carotid artery is one of the most commonly involved sites of systemic AS and is frequently used as a window into and assessment of the body’s large middle arteries, which can provide a general picture of systemic AS. According to studies, AS in the extracranial segment of the carotid artery is associated with the onset of cerebral infarction in 20%–25% of patients (Chen et al., 2019). Previous investigation (Karataş et al., 2016) has confirmed that the occurrence of AS is closely related to the inflammatory response mediated by inflammatory factors in the body, suggesting that the occurrence and progression of cerebral infarction may be related to the overexpression of inflammatory factors, dyslipidemia, and other factors. There is a critical need to address CAS prevention and treatment strategies.

In recent decades, both domestic and international researchers have identified AS a chronic inflammatory disease (Zhu et al., 2018). There is widespread agreement that inflammation plays a role in the development of AS (Geovanini and Libby, 2018). A growing number of clinical studies have attempted new anti-AS treatments based on anti-inflammation and immune regulation. Western medicine has had some success with lipid regulation, anti-inflammation, and anti-platelet aggregation. Nevertheless, there are some drawbacks to clinical application (Pang et al., 2017), such as muscle aches and pains, liver and kidney toxicity, increased transaminases (Backes et al., 2017), high drug production costs, the single target of the action, and so on (Li et al., 2020). As a result, research into CAS treatment is still a long way off. Traditional Chinese medicine (TCM) has been actively participating in the treatment of CAS in Asia and has demonstrated a definite curative effect with fewer side effects (Sun et al., 2021). TCM can affect multiple aspects of the occurrence and development of diseases from a holistic standpoint. TCM’s prevention and treatment of AS via immune inflammation-related pathways is a hot topic in current research. Extensive studies have discovered that qi deficiency and phlegm stasis are the most common types of evidence in CAS patients. The treatment of CAS primarily focuses on activating blood, resolving stasis, expelling phlegm, and benefiting qi (Wu et al., 2017), which shares similarities with western medicine in terms of lipid regulation and anti-inflammation. Randomized controlled trials (RCTs) on the clinical efficacy of AS have confirmed that Chinese medicines can reduce the size of CAS plaques and slow down the progression of CAS. However, few writers have drawn on any systematic study. The majority of RCTs were restricted to individual clinical observation and examination of a specific prescription. Most of the recommendations were self-recommended and based on empirical evidence, which was relatively weak. The safety and efficacy of these medications were not yet supported by scientific evidence due to the wide variety of Chinese medications, inconsistent dosage forms and doses, and some effective active ingredients of Chinese medications that had not undergone thorough pharmacological mechanisms of action studies. Given this, to aid the development of better clinical judgments, we thoroughly assessed the efficacy and safety of the YQHXZT treatment for CAS in this work.

The pathogenesis of AS is very complex. Inflammatory reactions not only run through all stages of the development of AS but also are closely related to the occurrence of various complications. The theory of immune inflammation has become a new breakthrough in the prevention and treatment of AS. The prevention and treatment of AS based on anti-inflammation and immune regulation have broad prospects and great potential. As one of the main blood supply vessels to the brain, the carotid artery plays an important role during AS. One study reported that the incidence of cerebral infarction in patients with greater than 70% carotid stenosis was approximately 13% (Zhang et al., 2020). There is no record of CAS in the Chinese medical literature. Based on its pathological nature, location, and clinical symptoms, it can be classified under the categories of “pulse paralysis”, “vertigo”, and “stroke.” Chinese medicine has recognized for thousands of years that the “veins” are the channels through which blood flows, and their physiological characteristics are similar to those of the “blood vessels” in Western medicine. In TCM, a qi deficiency is the root cause of the disease, and qi and blood are mutually beneficial. If qi is deficient, the blood is unable to move, and the blood is easily blocked and becomes stagnant. In addition, since the blood and fluid are of the same origin, when the arteries are blocked, the fluid stops, and the phlegm grows, the phlegm stagnates and adheres to the arteries, which turns into plaques over time and aggravates the progress of AS. In view of pathological factors such as phlegm, stasis, and turbidity, TCM clinically uses methods such as resolving phlegm, invigorating blood, and eliminating stasis to treat AS-related diseases (Jin et al., 2020). Statins are common clinical lipid-regulating drugs that can effectively improve lipid levels and plaque thickness and number in patients with CAS and reduce the incidence of adverse cardiovascular and cerebrovascular events (Liu et al., 2018). However, recently, investigators have examined the effects of western medicine alone are limited (Li, 2018), with shortcomings such as long duration, easy drug resistance, and side effects. In recent decades, TCM has received increasing attention due to its therapeutic effect and prospective future (Zhang et al., 2022). Previous research has established that the treatment of CAS using the YQHXZT method can effectively reduce intima-media thickness and plaque area, improve arterial stenosis, and enhance blood flow velocity (Chen and Zhang, 2017).

This study was based on Cochrane systematic evaluation principles to systematically evaluate the efficacy and safety of the combination of the YQHXZT method with western medicine in the treatment of CAS, and to evaluate the quality of evidence for the outcome indicators of the included studies by Grade profiler 3.6. As can be seen from above, the experimental group was more effective in improving CIMT [SMD = −0.97, 95%CI (−1.30, −0.65), p < 0.00001], reducing carotid plaque area [SMD = −1.98, 95%CI(−3.06,−0.89),p = 0.0003], lowering hs-CRP levels [SMD = −1.33, 95%CI(−1.59,−1.06),p < 0.00001] and LDL-C levels [SMD = −0.60, 95%CI(−0.83,−0.38), p < 0.00001]than the control group. Moreover, the experimental group was superior to PSV [SMD = -0.37, 95%CI(-0.59,-0.16), p = 0.0007]. In terms of clinical efficacy, the Chinese medicine clinical efficacy [RR = 1.64, 95%CI(1.39.1.94), p < 0.00001] and improvement of plaque area efficacy [RR = 1.36, 95% CI (1.22, 1.52), p < 0.0001] were both better in the experimental group. The incidence of adverse reactions was not statistically significant in the two groups [RD = −0.01, 95% CI (−0.04.0.01), p = 0.17]. The results of this review, combined with the grade evaluation, suggested that the outcome indicators LDL-C, hs-CRP, plaque area efficacy, PSV, and incidence of adverse events were moderate evidence, and the outcome indicators CIMT, plaque reduction area, and TCM clinical efficacy were low-quality evidence.

AS is a chronic vascular inflammatory response caused by the accumulation of LDL-C and is higher in patients with CAS. Within a certain range, the risk of AS increases logarithmically with higher LDL-C (Chen, 2020). The protein components of LDL particles in the body stimulate T lymphocytes to produce pro-inflammatory cytokines, which aggregate inflammatory factors such as CRP, IL-6, and monocyte chemoattractant protein-1, causing macrophages to phagocytose oxidized LDL and convert it into foam cells, which accumulate and eventually lead to the formation of AS (Beverly and Budoff, 2020). The vascular inflammatory response plays a key role in the pathogenesis of AS (Nie et al., 2020), influencing plaque formation, progression, and stability. Hs-CRP is a sensitive inflammatory factor reflecting vascular inflammatory mechanisms, which can be involved in related gene regulation and is closely related to the formation and breakdown of AS (Chen et al., 2021a). Hs-CRP can induce inflammatory and adhesion factors and make them accumulate under the vascular endo cortex, promote the formation of foam cells, and promote interstitial degradation and vascular smooth muscle cell apoptosis by activating the inflammatory pathway. This increases the risk of AS and plaque rupture. Tigkiropoulos et al. (Tigkiropoulos et al., 2019)demonstrated that PSV could be used to assess the degree of arterial stenosis. Studies suggested that every 0.1 mm thickening of the IMT increased the risk of infarction by 10%–15% and stroke by 13%–18%, especially in unstable plaques, which were more likely to dislodge and lead to stroke (Liu et al., 2020). Research has confirmed Chinese medicine’s effectiveness as an effective means of treating cardiovascular diseases (Hao et al., 2017). For example, Huangjing can play a role by regulating lipid metabolism, reducing inflammation, and improving oxidative stress (Chen et al., 2021b). Data from several studies suggest that increasingly Chinese medicine prescriptions, including Chinese patent medicine, classical prescription decoction, self-made prescription, etc., have been confirmed to regulate immune inflammation and antioxidant in a variety of ways (Tang et al., 2022). According to the composition and compatibility effect of the prescription, the most common is to benefit qi, promote blood circulation, and eliminate phlegm. The main pathways involved include Nf-κB pathway, the MAPKs pathway, the Toll-like receptor pathway, the inflammatory body pathway, etc (Figure 17). More attention has been paid to the first two pathways, whose mechanisms may be mainly by inhibiting NF-κB protein phosphorylation or NF-κB p65 gene expression and can also be combined with the MAPKs pathway to regulate the expression of related inflammatory cytokines to play an anti-inflammatory role. For example, berberine, the main compound of Huanglian, can lower blood lipid, antioxidation, anti-inflammation, and protect vascular endothelium (Xu et al., 2019) by downregulating the serum inflammatory factor levels, inhibiting MAPK phosphorylation, inhibiting NF-κBp65 mRNA expression (Feng et al., 2017).

In terms of publication bias, the funnel plot and Begg’s test were used to prove that there was no obvious publication bias in this study, and that the study results were reliable. In clinical work, it was found that AS was often combined with other diseases at the same time. According to the existing literature reports, TCM could also improve some symptoms and indicators of concomitant diseases, but its efficacy still needs further standardized study. This study, combined with grade evaluation, provides an evidence-based basis for clinical treatment direction. Compared with the control group, the YQHXZT formula was more comprehensive and safer, which was worthy of further clinical promotion.

This study has shown that the combination of the YQHXZT method could inhibit carotid intimal thickening, reduce plaque area, lower LDL-C and hs-CRP levels, and improve clinical efficacy. At the same time, the combination of YQHXZT methods has not found a significant increase in the risk of adverse reactions. Overall, this study probably strengthens the idea that the combination of Chinese medicine and western medicine can slow down the CAS process and improve the prognosis of the disease by inhibiting the inflammatory response and regulating lipid metabolism. That provides new attempts for the treatment of CAS in the future.

However, this study also had some limitations: ① Some of the included studies did not describe the stochastic method in detail. No trial mentioned allocation concealment and blinding, and selection bias may have occurred. The included studies were Chinese studies with insufficient research dimensions. ② Mostly limited to the observation and analysis of a prescription, should focus on some good curative effects of YQHXZT by TCM fixed prescription or Chinese patent medicine. Therefore, in the future, we should pay attention to the improvement of methodology and carry out multicenter, large sample, high-quality, long-course double-blind RCT with Chinese medicine characteristics for verification. At the same time, the basic research on the treatment of CAS with TCM was relatively weak, and the research on the mechanism of action of drugs needed to be more in-depth and clearer (Yang et al., 2020).