Clinical Value Of PAC-1 In Assessing Intensive Antiplatelet Therapy After PCI For Acute Myocardial Infarction

Objective:To assess the changes in platelet membrane glycoprotein IIb/IIIa fibrinogen receptor expression levels before and after intensive peri-procedural antiplatelet therapy for acute myocardial infarction PCI and the clinical prognosis of PAC-1 on patients with acute myocardial infarction 30 days after PCI.Methods:Four hundred and thirteen patients attending the emergency department of the Affiliated Hospital of Inner Mongolia Medical University for acute myocardial infarction from July2021 to September 2022 were consecutively selected(all met the inclusion and exclusion criteria).The patients were divided into low-dose group 0.05 μg(kg-min)(N=96),half-dose group 0.075 μg(kg-min)(N=102),full-dose group 0.15 μg(kg-min)(N= 64)and patients who did not use tirofiban injection were the control group(N=151).The activated platelets in the peripheral venous blood of patients with acute myocardial infarction before and after intensive antiplatelet therapy were labeled by PAC-1,a marker that can fluorescently label platelet membrane glycoprotein IIb/IIIa fibrinogen receptors,and the ratio of activated platelets in each dose group was measured by flow cytometry.The effect of intensive anti-platelet therapy was observed in each group.The study will also follow up patients with acute myocardial infarction 30 days after PCI in each group,with a reduced number of follow-up visits due to missed connections in each group: control(N=136),low dose(N=89)half dose(N=93),full dose(N=59).The main follow-up included cardiovascular adverse events,bleeding events and cardiac function,comparing the incidence of major cardiovascular adverse events,the incidence of bleeding events and changes in cardiac function 30 days after PCI with intensive antiplatelet therapy in each group.Finally,the occurrence of bleeding events was predicted by pre-procedure PAC-1.Statistics were analysed using SPSS 26.0 software and P < 0.05 was considered a statistically significant difference.Results:In the study of activated platelet counts by fluorescent PAC-1 labelling,flow cytometry results showed no statistical difference in PAC-1 between groups before PCI(P>0.05)and a statistically significant difference between groups(P<0.05)as the dose of tirofiban was increased 18 h after PCI.There was a statistically significant decrease in the Δchange value between the experimental groups compared to the control group,with a statistically significant difference between the half-dose and full-dose groups compared to the low-dose group(P<0.05),and no statistically significant difference between the half-dose group compared to the full-dose group(P>0.05).In the 30-day post-PCI follow-up study between groups,there was no statistically significant difference between groups in pre-PCI LVEF values(P>0.05)and 30-day post-PCI LVEF values(P>0.05)for cardiac ultrasound.There was no statistically significant difference between groups in LVEDD values before PCI(P>0.05),and no statistically significant difference between groups in LVEDD values 30 days after PCI(P>0.05),and no statistically significant difference between groups in Δchange values,i.e.the difference between LVEDD values 30 days after PCI and before PCI.There was no statistical difference in the incidence of MACE events between the groups(P>0.05),and the incidence of MACE events tended to decrease as the dose of tirofiban increased.In terms of the incidence of bleeding events within30 days after PCI,there was no statistical difference between the low-dose group and the control group for microbleeding events(P>0.05),and no statistical difference between the half-dose group and the control group for microbleeding events(P>0.05).There was a statistically significant difference in the incidence of microbleeding events in the full-dose group compared to the control and low-dose groups(P<0.05)and no statistically significant difference compared to the half-dose group(P>0.05).There was no statistically significant difference in the trend towards an increase in moderate bleeding events between groups as the dose of tirofiban was increased(P>0.05).There was no statistical difference in major bleeding events compared between groups(P>0.05)and no fatal bleeding events occurred in any of the groups.The area under the ROC curve of preoperative PAC-1 for predicting 30-day postoperative bleeding events was 0.78(0.67,0.89),the cut-off value was 44.88,the sensitivity was 85.92%,the specificity was 68.97%,and the Yordon index was 0.55,indicating that preoperative PAC-1 has some predictive value for 30-day postoperative bleeding events.Conclusion:1.The proportion of activated platelets labelled by PAC-1 was reduced in the half-dose group compared with the low-dose group in patients with acute myocardial infarction using tirofiban injection,and the proportion of activated platelets labelled by PAC-1 did not change significantly in the half-dose group compared with the full-dose group.2.Patients with acute myocardial infarction showed a trend towards a decrease in the incidence of major cardiovascular adverse events 30 days after PCI with increasing doses of tirofiban injection,with no significant change in cardiac function,but an increased risk of bleeding.3.Pre-procedural PAC-1 has some predictive value for the risk of bleeding following intensive antiplatelet therapy after PCI for acute myocardial infarction.