Previous studies have found associations between monocyte count, high-density lipoprotein cholesterol (HDL-C), and thyroid-stimulating hormone (TSH) with acute coronary syndrome (ACS). However, research on the correlation between the monocyte count to high-density lipoprotein cholesterol ratio (MHR) and the onset of ACS is limited. The association between MHR, TSH, and the onset of ACS in postmenopausal women remains unclear.

To explore the predictive value of MHR and TSH for the onset of ACS in postmenopausal women and to investigate the correlation between these indicators and the degree of coronary artery stenosis in patients.

A total of 325 postmenopausal women hospitalized in the Department of Cardiology at Northern Jiangsu People's Hospital, from 2020 to 2021 and who underwent coronary angiography were selected as the study subjects. Patient general information was collected through the electronic medical record system. Venous blood was collected upon admission to measure monocyte count, total cholesterol (TC), triglycerides (TG), HDL-C, low-density lipoprotein cholesterol (LDL-C), and TSH. Left ventricular ejection fraction (LVEF) was measured using the biplane Simpson method, and coronary artery lesions were observed through coronary angiography. The Gensini scoring system was used to uniformly measure the extent of coronary artery lesions. Patients meeting the diagnostic criteria for ACS were classified as the ACS group (n=184), and non-ACS patients as the control group (n=141). The ACS group was further divided into subgroups based on the tertiles of the Gensini score: ≤36.5 as the low-risk subgroup (n=59), 36.6-66.5 as the moderate-risk subgroup (n=64), and >66.5 as the high-risk subgroup (n=61). Univariate and multivariate Logistic regression analyses were used to explore the influencing factors of ACS. The receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of TSH, MHR, and combined detection for ACS and to calculate the area under the curve (AUC). Spearman's rank correlation analysis was used to explore the correlation between TSH, MHR, and combined detection indicators with the Gensini score.

The baseline data of patients in the ACS and control groups showed that BMI, smoking rate, hypertension, diabetes, LDL-C, monocytes, TSH, and MHR in the ACS group were higher than in the control group, while LVEF and HDL-C were lower (P<0.05). Multivariate Logistic regression analysis showed that smoking, hypertension, BMI≥24.0 kg/m², LDL-C≥3.30 mmol/L, TSH≥2.1 mU/L, and MHR≥0.25 were risk factors for the occurrence of ACS in postmenopausal elderly women, and HDL-C≥1.2 mmol/L was a protective factor (P<0.05). The ROC curve analysis demonstrated that the AUC for MHR, TSH, and the combined predictive index in diagnosing ACS in postmenopausal women were 0.777 (95%CI=0.725-0.830, P<0.001), 0.747 (95%CI=0.694-0.800, P<0.001), and 0.810 (95%CI=0.764-0.857, P<0.001), respectively. In the moderate and high-risk subgroups, MHR and TSH were higher than in the low-risk subgroup, and the high-risk subgroup had higher MHR and TSH than the moderate-risk subgroup (P<0.05). Spearman's rank correlation analysis showed that in the ACS group, MHR (r_s=0.497, P<0.01), TSH (r_s=0.498, P<0.01), and the combined predictive indicators were positively correlated with the Gensini score (r_s=0.600, P<0.001) .

Elevated TSH and MHR are independent risk factors for the occurrence of ACS in postmenopausal women. Both indicators and their combination have certain sensitivity and specificity for disease prediction and are correlated with the extent of coronary artery lesions in patients, which has certain clinical application value for the early identification and risk assessment of ACS in postmenopausal women.