Lipoprotein(a) variations between Chronic Coronary Syndrome and Acute Myocardial Infarction and their relation to the severity of coronary artery stenosis

Background Lp(a) levels and the degree of coronary artery stenosis in patients with CAD at different times [e.g., acute myocardial infarction (AMI), chronic coronary syndrome (CCS)] are closely related to patients with coronary artery disease (CAD), but the differences in Lp(a) levels and the relationship between Lp(a) levels and the degree of coronary artery stenosis are unclear. Methods Based on the inclusion and exclusion criteria, we screened 217 patients with CCS and 141 patients with AMI. Their data were collected separately, including gender, age, marital status, hypertension, diabetes, smoking, drinking,troponin I, Creatine Kinase Isoenzyme(CKMB), Lp(a), apolipoprotein a [apo(a)],apolipoprotein b [apo(b)], LDL, HDL, TG, TC, D-dimer, fibrinogen, homocysteine, number of coronary artery lesions and the degree of stenosis,and echocardiography related indices.The correlation between Lp(a) level and the degree of coronary artery stenosis was tested by Spearman rank correlation, and the relationship between Lp(a) level and coronary artery obstruction was clarified using univarite and multivariate binary logistic regression analysis, and ROC curves were plotted to clarify the value of Lp(a) in predicting coronary artery obstruction and the cut-off value. Results In our study, the median Lp(a) concentration was significantly higher in AMI patients than CCS(336.0 vs 135.0 mg/L).Lp(a) was highly associated with the degree of coronary stenosis in patients with CCS(r = 0.811,p<0.001) and was not found in patients with AMI(r = 0.029, p > 0.05).Lp(a) was associated with coronary artery obstruction(define as coronary artery stenosis ≥ 50%) in a multivariate regression analysis compared to other factors(OR:1.024;95%CI:1.016–1.032).The receiver operating characteristic(ROC) curve shows that the area under curve(AUC) of lipoprotein(a) is 93.9%,and the cut-off value of Lp(a) for predicting coronary artery obstruction was 130 mg/L(sensitivity: 85.83% ,specificity: 88.46%). Conclusions Lp(a) levels were considerably greater in AMI patients compared to CCS patients, but they did not correlate with the severity of coronary artery stenosis in AMI patients. The level of coronary stenosis can be predicted by Lp(a). In patients with chronic coronary syndrome, Lp(a) > 130 mg/L indicates coronary artery stenosis > 50%.