Objective To explore the relationships of serum S100 calcium binding protein A8 (S100A8) and S100 calcium binding protein A9 (S100A9) levels with thrombus burden in patients with acute ST-segment elevation myocardial infarction (STEMI).

Methods A total of 85 STEMI patients were selected and treated with percutaneous coronary intervention (PCI). According to the coronary angiography and intraoperative situation of interventional therapy, the patients were divided into high thrombotic burden group thrombosis grading of thrombolysis in myocardial infarction (TIMI) was grade 4 to 5 with 40 cases and low thrombotic burden group (thrombosis grading of TIMI grade was below grade 4) with 45 cases. Serum S100A8 and S100A9 levels were detected, relevant factors affecting high thrombotic burden in STEMI patients were analyzed, and the values of S100A9 and S100A8 in predicting high thrombotic burden in STEMI patients were explored. The patients were followed up for 3 months after PCI, and the complications were recorded.

Results In the high thrombotic burden group, the age and the ratios of male, smoking history, type 2 diabetes and right coronary artery infarction and the preoperative Gensini score, total cholesterol and low-density lipoprotein cholesterol levels were also significantly higher than those in the low thrombotic burden group (P < 0.05). Compared with the low thrombotic burden group, the serum S100A9 and S100A8 levels were significantly higher in the high thrombotic burden group (P < 0.05). Preoperative Gensini score, low-density lipoprotein cholesterol, S100A9 and S100A8 were the risk factors for high thrombotic burden in STEMI patients (P < 0.05). The combined prediction of S100A9, S100A8, Gensini score and low-density lipoprotein cholesterol for high thrombotic burden in STEMI patients showed a significant higher area under the curve when compared to the independent prediction of the above indicators predicted alone (Z=4.462, 4.817, 3.959, 4.438, P < 0.05). Within 3 months after PCI, 12 cases in the complication group had complications, including 6 cases of puncture site bleeding, 3 cases of hematoma, 2 cases of stent thrombosis, and 1 case of acute coronary artery occlusion. A total of 72 patients without complications were included in no complication group. The serum levels of S100A9 and S100A8 as well as the high thrombotic burden ratio in the complication group were significantly higher than those in the no complication group (P < 0.05).

Conclusion Both serum S100A9 and S100A8 levels increase in STEMI patients with high thrombotic burden, and are helpful for evaluating the arterial thrombotic burden status before PCI in STEMI patients.