Acute coronary syndrome (ACS) is a group of pathological clinical syndromes characterized with coronary atherosclerotic plaque rupture or erosion, and secondary complete or incomplete occlusion of thrombosis. The selection of specific and sensitive serological markers and detection methods has an important clinical value for rapid, accurate early diagnosis, assessment, and treatment of ACS.

To explore the correlation of plasma nucleolin (NCL) with the stability and severity of coronary artery plaques in ACS patients, and to analyze the value of NCL in predicting ACS.

A total of 117 ACS patients admitted to the Cardiovascular Department of the First Hospital of Changsha in 2022 and examined by coronary angiography were selected as the study subjects, including 36 cases of unstable angina (UA group), 36 cases of non-ST segment elevation myocardial infarction (NSTEMI group), and 45 cases of ST segment elevation myocardial infarction (STEMI group). During the same period, 39 cases of non-ACS patients were selected as the control group. Blood samples and general clinical data were collected. Plasma levels of NCL, C-reactive protein (CRP), and low-density lipoprotein cholesterol (LDL-C) were measured. According to the results of coronary angiography, ACS patients were divided into non-lesion group, single vessel lesion group, double vessel lesion group, and multi-vessel lesion group. ACS patients were further assigned into the vulnerable plaque group and stable plaque group based on the characteristics of ultrasonic echo. Those without atherosclerotic plaque were classified as plaque-free group. The correlation of NCL levels with CRP and LDL-C levels in different groups of ACS patients was evaluated. The correlation of NCL levels with the number of coronary artery lesions, severity of coronary artery lesions, and the Gensini score in ACS patients was identified. Multivariate Logistic regression analysis was used to identify whether plasma NCL was an independent risk factor for ACS. The optimal cut-off value of plasma NCL in predicting ACS was determined by the receiver operating characteristic (ROC) curves.

Plasma NCL levels were positively correlated with LDL-C and CRP (r=0.572, and 0.639, respectively; both P<0.05). Plasma NCL levels were compared in ACS patients with varied degrees of carotid plaque, and they were higher in the vulnerable plaque group (n=73), followed by the stable plaque group (n=49) and plaque-free group (n=33). Plasma NCL was positively correlated with the degree of carotid plaque (r=0.543, P<0.05). Plasma NCL levels in ACS patients were significantly higher in the multi-vessel lesion group (n=39) than the double vessel lesion group (n=49) (P<0.05), while plasma NCL levels were significantly higher in the double vessel lesion group (n=49) than the single vessel lesion group (n=29) (P<0.05). Plasma NCL was positively correlated with the number of diseased coronary vessels in ACS patients (r=0.445, P<0.05). Plasma NCL levels were significantly higher in the high Gensini score group than those of the low Gensini score and medium Gensini score groups (P<0.05), which were positively correlated with the number of diseased coronary vessels (r=0.799, P<0.05). Multivariate Logistic regression analysis showed that increased NCL was an independent risk factor for ACS, with the optimal cut-off value of 0.765 ng/mL in ROC curves.

Plasma NCL levels have a certain clinical significances in evaluating plaque stability, recognizing ACS and risk stratification of ACS patients. Plasma NCL level is positively correlated with the number of coronary artery lesions and Gensini score, serving as a reference indicator for predicting and evaluating the severity of coronary artery lesions to a certain extent. Elevated plasma NCL levels may be an independent risk factor for the occurrence of ACS and have predictive diagnostic value for ACS.