A Clinical Study On The Effects Of Different Loading Doses Of Aspirin On Patients Undergoing Emergency Coronary Intervention

Background and purpose: Aspirin,as one of the most widely used antiplatelet drugs,has been the base drug for STEMI patients.With the development of antithrombotic drugs,especially with the appearances of clopidogrel,ticagrelor etc,aspirin's status has been constantly challenged and the specific dosage has changed accordingly.Related guidelines for patients planning for emergency interventional therapy after STEMI,the recommended aspirin loading dose is gradually transitioning from an early 300 mg to 100-300mg(depending on prior aspirin use).The latest guidelines,both domestic and international,drop the emphasis on whether or not patients have taken aspirin in the past,and instead recommend the loading dose of aspirin as 100-300 mg.The guidelines' latest recommendations for aspirin's loading dose appear to relax the dosing requirements,but they also cause some confusion in clinical practice.In view of the importance of aspirin in emergency coronary intervention antithrombotic therapy and the existence of many adverse reactions,more evidence-based evidence is urgently needed to provide a basis for individualized regimen of aspirin dose in patients.This study explores the optimal loading dose regimen of aspirin by observing the effects of aspirin of different loading dose on inhibition of platelet aggregation in patients with emergency coronary intervention and the effects of perioperative thrombus and bleeding events.Methods: Enrolling acute STEMI patients who were for direct PCI within12 h after bursting out and none of the enrolled patients had received aspirin for the previous 14 days,and who were randomly divided into the aspirin 100 mg loading dose group(experimental group)and the aspirin 300 mg loading dose group(control group).Both groups were treated with P2Y12 receptor inhibitors(clopidogrel 300 mg or ticagrelor 180mg).Platelet aggregation function was measured before(0h)and at different time points(1h,2h and 8h)after administration in the two groups,and the inhibition of platelet aggregation induced by AA and ADP were calculated respectively.Inhibition of platelet aggregationand ischmia events(including perioperative death,ischemic stroke,recurrent angina pectoris,recurrent myocardial infarction,gastrointestinal symptoms and incidence of major bleeding events)were observed and compared in the two groups at different time points in the perioperative period.Results: 186 STEMI patients(146 male,ages 29 to 75)were enrolled in the study finally,with 91 in the experimental group and 95 in the control group.The results showed that the inhibition of platelet aggregation AA was 40.8% in the experimental group and 42.8% in the control group at 1h after administration(P=0.134),and the difference was not statistically significant.At 2h and 8h after surgery,the inhibition of platelet aggregation AA was also not significantly different between the two groups(54.8% vs 56.3%,P > 0.05 and 85.3% vs86.7%,P > 0.05).The proportion of patients whose immediate blood flow of TIMI reached grade 3 after surgery was 89.0% in the experimental group and 89.4% in the control group(P=0.919).There was no difference during the hospitalization in the incidence of ischmia events between the two groups(14.3% in the experimental group and 16.8% in the control group,P=0.631).Primary and secondary bleeding defined by TIMI during hospitalization was 8.8% in the experimental group and11.6% in the control group,P=0.530.The gastrointestinal symptoms between the two groups were 15.4% in the experimental group and 27.4% in the control group,P=0.046,showing a statistical difference(P < 0.05).Conclusion:The inhibition of platelet aggregation were similar at different ti me points in the patients receiving emergency PCI after STEMI treated with aspiri n loading dose of 100 mg and 300 mg,and there was no significant difference in it a t ischemic eventsduring hospitalization.The proportion of bleeding events defined by TIMI in the 100 mg aspirin group was less than that in the 300 mg aspirin group,but there was no statistical difference.100 mg can significantly reduce the incidenc e of gastrointestinal symptoms.