Abstract: Objective To investigate the predictive value of atherogenic index of plasma (AIP) combined with low-density lipoprotein cholesterol (LDL-C) for intracoronary thrombus load in elderly patients with ST-segment elevation myocardial infarction (STEMI) undergoing emergency percutaneous coronary intervention (PCI). Methods A retrospective analysis was performed on 387 elderly STEMI patients who underwent emergency PCI at General Hospital of Ningxia Medical University from January to December 2019. According to the thrombolysis in myocardial infarction (TIMI) thrombus grading criteria, the patients were divided into small thrombus load (STB) group (273 cases) and large thrombus load (LTB) group (114 cases). The clinical data of the two groups were compared.Multivariate logistic regression was used to identify independent risk factors for LTB, and receiver operating characteristic (ROC) curve analysis was applied to evaluate the predictive performance of AIP and LDL-C. Results Compared to the STB group, the LTB group had significantly lower rates of Killip grade 1 and postoperative TIMI flow grade 3, lower levels of systolic/diastolic blood pressure and left ventricular ejection fraction(LVEF), but higher levels of serum creatinine, troponin Ⅰ, triglyceride(TG), LDL-C, AIP, door-to-balloon time, and a higher proportion of preoperative TIMI flow grade 0-2 (all P<0.05). Multivariate logistic regression analysis showed that AIP, LDL-C, portal time, and preoperative TIMI blood flow grade 0-2 were independent risk factors for LTB, while Killip grade 1 was a protective factor. The area under the ROC curve of AIP combined with LDL-C for predicting LTB was 0.707 (95%CI: 0.648-0.765; P<0.001), with a sensitivity of 73.7% and a specificity of 36.3%. Conclusions AIP and LDL-C are independent risk factors for high thrombus burden in elderly STEMI patients, and their combination shows certain predictive value for intracoronary LTB, which may serve as an auxiliary indicator for clinical risk assessment.

Key words: ST segment elevation myocardial infarction, atherogenic index of plasma, low-density lipoprotein cholesterol, thrombus load