Coronary collateral circulation (CCC) reduces the degree of myocardial ischemia and improves prognosis of patients with severe coronary artery stenosis, but CCC development varies significantly among different patients. The influencing factors of CCC development still remain clear, but the increase of inflammation response and inflammatory markers is associated with CCC. The C-reactive protein to albumin ratio (CAR) is a newly reported indicator of inflammation, which has been shown in several studies to be superior to C-reactive protein (CRP) and albumin (ALB) in reflecting cardiovascular inflammation. At present, there are few studies on the correlation between CAR level and CCC development.

To investigate the correlation between CAR and CCC development in unstable angina pectoris (UAP) patients.

One hundred and thirty-five UAP patients who underwent percutaneous coronary intervention during their hospitalization in the Cardiology Department of the First Affiliated Hospital of Soochow University from December 2021 to November 2022 were enrolled as study subjects. The clinical data of the patients were collected and the CCC grade was assessed using the Rentrop grading method. The patients were divided into the well-developed CCC group (Rentrop grade 2-3, n=52) and poor-developed CCC group (Rentrop grade 0-1, n=83) according to the angiographic results. Univariate Logistic regression and multivariate Logistic regression analyses were used to explore the influencing factors of poor-developed CCC in UAP patients. Receiver operating characteristic curves (ROC curves) were plotted to evaluate the predictive value of CRP, ALB and CAR on poor-developed CCC, the area under the ROC curve (AUC) was calculated.

A total of 135 UAP patients were enrolled, including 87 males and 48 females, with an average age of (65.5±7.1) years. The proportions of diabetes mellitus, smoking, CRP, and CAR of patients in the poor-developed CCC group were significantly higher than the well-developed CCC group (P<0.05) . Multivariate Logistic regression analysis results showed that CAR and diabetes mellitus were influencing factors for poor-developed CCC in UAP patients (P<0.05) . The ROC curve results of CRP, ALB, and CAR in predicting poor-developed CCC showed that the AUC of CRP, ALB, and CAR in predicting poor-developed CCC in UAP patients were 0.771〔95%CI (0.691, 0.851) 〕, 0.745〔95%CI (0.663, 0.851) 〕, 0.813〔95%CI (0.739, 0.886) 〕. The AUC of CAR in predicting poor-developed CCC was higher than CRP (Z=3.869, P<0.001) , ALB (Z=3.044, P=0.002) , the AUC of CRP in predicting poor-developed CCC was higher than ALB (Z=2.000, P=0.046) .

CAR and diabetes mellitus are influencing factors for poor-developed CCC in UAP patients, elevated CAR level can predict poor-developed CCC with higher predictive value than CRP and ALB.

冠状动脉侧支循环（CCC）能减轻严重冠状动脉狭窄患者的心肌缺血程度，改善其预后，但不同患者的CCC形成差异显著。影响CCC形成的因素尚不完全清楚，但炎症和一些炎症标志物的增加与CCC存在相关性。C反应蛋白/白蛋白比值（CAR）是新报道的炎症指标，多项研究表明其在反映心血管炎症方面优于C反应蛋白（CRP）和白蛋白（ALB）。目前CAR水平与CCC形成的相关研究甚少。

探讨CAR与不稳定型心绞痛（UAP）患者CCC形成的关系。

纳入2021年12月—2022年11月在苏州大学附属第一医院心血管内科住院并接受经皮冠状动脉介入术治疗的135例UAP患者为研究对象，收集患者的临床资料，采用Rentrop分级法评定CCC级别，将患者分为CCC形成不良组（Rentrop分级0~1级，n=52）和CCC形成良好组（Rentrop分级2~3级，n=83）。采用单因素Logistic回归和多因素Logistic回归分析探讨UAP患者CCC形成不良的影响因素。绘制受试者工作特征曲线（ROC曲线）评价CRP、ALB及CAR对UAP患者CCC形成不良的预测价值，计算ROC曲线下面积（AUC）。

共纳入135例UAP患者，其中男87例，女48例，平均年龄（65.5±7.1）岁。CCC形成不良组患者糖尿病、吸烟史比例、CRP、CAR高于CCC形成良好组，ALB低于CCC形成良好组（P<0.05）。多因素Logistic回归分析结果显示CAR、糖尿病是UAP患者CCC形成不良的影响因素（P<0.05）。绘制CRP、ALB、CAR预测UAP患者CCC形成不良的ROC曲线，结果显示，CRP、ALB、CAR预测CCC形成不良的AUC分别为0.771〔95%CI（0.691，0.851）〕、0.745〔95%CI（0.663，0.827）〕、0.813〔95%CI（0.739，0.886）〕；其中CAR预测UAP患者CCC形成不良的AUC高于CRP（Z=3.869，P<0.001）、ALB（Z=3.044，P=0.002），CRP预测UAP患者CCC形成不良的AUC高于ALB（Z=2.000，P=0.046）。

CAR、糖尿病是UAP患者CCC形成不良的影响因素，CAR升高可预测CCC形成不良，其预测价值高于CRP和ALB。