Acute Myocardial Infarction (AMI) remains one of the leading threats to global public health. Despite available reperfusion therapies, major adverse cardiovascular and cerebral events (MACCEs) associated with AMI continue to be a leading cause of death worldwide. This is particularly true for patients with AMI and concomitant diabetes mellitus, where coronary artery disease is more complex and severe, making early detection and prognosis of long-term outcomes for these patients challenging. Therefore, the identification of simple and accessible laboratory markers could facilitate the prediction of post-percutaneous coronary intervention (PCI) MACCEs in patients with type 2 diabetes mellitus (T2DM) and AMI.

To investigate the predictive value of the serum C-reactive protein (CRP) /albumin (Alb) ratio (CAR) for long-term MACCEs following PCI in patients with T2DM and AMI.

A total of 1 683 patients with T2DM and AMI treated at the Department of Cardiovascular Medicine, General Hospital of Ningxia Medical University between 2014 and 2019 were enrolled. General clinical data and test results were collected for these patients. Follow-ups were conducted via telephone or outpatient visits, with a median follow-up period of 5.6 years. MACCEs were defined as all-cause mortality, non-fatal myocardial infarction, recurrent unstable angina, non-fatal stroke, new-onset heart failure, or rehospitalization for worsening heart failure, and revascularization. Patients were divided into the MACCEs group (508 cases) and the non-MACCEs group (1 175 cases) based on the occurrence of MACCEs during the follow-up period. Univariate and multivariate Logistic regression analyses were performed to identify factors influencing MACCEs in patients with T2DM and AMI. Kaplan-Meier survival curves were plotted, and the Log-rank test was used for comparisons. Receiver operating characteristic (ROC) curve analysis assessed the predictive efficacy of CAR for long-term MACCEs in patients with T2DM and AMI, while the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) indices evaluated the improvement in prognostic assessment provided by CAR.

Among the 1 683 patients, 508 (30.18%) experienced MACCEs. Multivariate Logistic regression analysis indicated that hypertension [OR (95%CI) =1.994 (1.142-3.483) ], length of coronary stent implanted [OR (95%CI) =1.031 (1.002-1.062) ], CRP [OR (95%CI) =0.950 (0.915-0.986) ], Alb [OR (95%CI) =0.933 (0.880-0.989) ], and CAR [OR (95%CI) =5.582 (1.705-18.277) ] were significant predictors of post-PCI MACCEs in patients with T2DM and AMI (P<0.05). Based on the median CAR level (0.86), patients were divided into two groups: CAR<0.86 and CAR≥0.86. The log-rank test showed that the incidence of MACCEs was significantly higher in the CAR≥0.86 group compared to the CAR<0.86 group (52.68% vs. 22.92%; χ²=65.65, P<0.001). The ROC curve indicated that the area under the curve (AUC) for CAR in predicting MACCEs in patients with T2DM and AMI was 0.728 (95%CI=0.702-0.754), with an optimal cut-off value of 0.576, sensitivity of 0.617, and specificity of 0.747. Compared to baseline models, CAR significantly improved the prediction of adverse cardio-cerebral events (NRI=0.377, IDI=0.166, C-index =0.690; P<0.05) .

CAR is an effective predictive marker for the risk of long-term MACCEs in patients with T2DM and AMI following PCI.

急性心肌梗死（AMI）是威胁全球公众健康的主要原因之一。虽然已有相应的再灌注治疗策略，但AMI相关的主要不良心脑血管事件（MACCEs）仍然是全世界人口死亡的原因之一。尤其合并糖尿病的AMI患者，因冠状动脉病变复杂，病变程度严重，尽早发现和判断该部分患者远期预后相对困难，因此寻找相对简便、易获得的实验室指标，有利于为2型糖尿病（T2DM）合并AMI患者经皮冠状动脉介入（PCI）术后MACCEs的预测提供依据。

探讨血清C反应蛋白（CRP）/白蛋白（Alb）比值（CAR）对T2DM合并AMI患者PCI术后远期MACCEs的预测价值。

纳入2014—2019年就诊于宁夏医科大学总医院心血管内科1 683例T2DM合并AMI患者为研究对象，收集患者的一般临床资料与检查结果。对所有患者进行电话或门诊随访，以全因死亡、非致死性心肌梗死、再发不稳定型心绞痛、非致死性脑卒中、新发心力衰竭或心力衰竭加重再入院、再次血运重建作为MACCEs。根据患者随访期间是否发生MACCEs分为MACCEs组（508例）和非MACCEs组（1 175例）。采用单因素及多因素Logistic回归分析探讨T2DM合并AMI患者MACCEs事件的影响因素。采用Kaplan-Meier法绘制患者的生存曲线，生存曲线的比较采用Log-rank检验。采用受试者工作特征（ROC）曲线分析CAR对T2DM合并AMI患者远期发生MACCEs的预测效能，使用净重分类改善指标（NRI）和综合判别指数（IDI）评价CAR对T2DM合并AMI患者预后评估的改善效果。

1 683例患者中508例（30.18%）患者发生MACCEs。多因素Logistic回归分析显示高血压病[OR（95%CI）=1.994（1.142~3.483）]、冠状动脉植入支架长度[OR（95%CI）=1.031（1.002~1.062）]、CRP[OR（95%CI）=0.950（0.915~0.986）]、Alb[OR（95%CI）=0.933（0.880~0.989）]及CAR[OR（95%CI）=5.582（1.705~18.277）]是T2DM合并AMI患者PCI术后发生MACCEs的影响因素（P<0.05）。根据CAR中位表达水平（0.86），将患者分为CAR<0.86组和CAR≥0.86组，Log-rank检验结果显示，CAR≥0.86组MACCEs发生率高于CAR<0.86组（52.68%与22.92%；χ²=65.65，P<0.001）。ROC曲线显示CAR预测T2DM合并AMI患者发生MACCEs的ROC曲线下面积为0.728（95%CI=0.702~0.754），最佳截断值为0.576，灵敏度为0.617，特异度为0.747。在基线模型基础上，与CRP、Alb相比，CAR能明显改善对患者发生MACCEs的预测效果（NRI=0.377，IDI=0.166，C指数=0.690；P<0.05）。

CAR是T2DM合并AMI患者PCI术后远期MACCEs发生风险的有效预测指标。