Comparasion Between The Effects Of Two Antiplatelet Treatments On Patients With Acute STEMI Undergoing Primary PCI

Objective:Acute ST segment elevation myocardial infarction(STEMI) refers to acute myocardial ischemic necrosis, pathogenesis of which is often plateletactivation and thrombosis on the basis of unstable coronary plaque rupture, leading to complete coronary artery occlusion. Since percutaneous coronary intervention( PCI) can effectively revascularize the infarct related artery(IRA), currently it has become the most effective treatment for acute STEMI. However, to a part of patients with STEMI who underwent the primary PCI, IRA revascularizasion does not bring about the improvement of the myocardial microcirculation perfusion, namely poor myocardial perfusion, even a “no reflow”. Many studies have shown that, one most important mechanism of the no-reflow is micro-embolism, and antiplatelet therapy is likely to be benefcial to prevent no-reflow. The latese guideline on STEMI/PCI recommended aspirin of loading dose and clopidogrel or ticagrelor of loading dose should be given to patients with STEMI before PPCI. Currently clopidogrel is used more widely in China, but the phenomenon of loading dose does not meet the standard is common.Platelet membrane glycoprotein(GP)IIb/IIIa receptor antagonist can block the final pathway of platelet aggregation, currently it is the strongest antiplatelet drugs. Some international researches show that the benifit and bleeding risk of application of GP IIb/IIIa receptor antagonist in the upstream of PPCI is still controversial. There have been a number of studies on the treatment combining aspirin, clopidogrel and GP IIb/IIIa receptor antagonist of STEMI in the international, but for Chinese people, the number is relatively less. The study aimed to compare the effectiveness and safety of dual antiplatelet regimen(containing aspirin of 300 mg and clopidogrel of 600mg)and triple antiplatelet regimen(containing aspirin of 300 mg, clopidogrel of 300 mg and tirofiban) before PPCI for patients with STEMI.Methods: Patients with a first STAMI presenting <12hours from onset of symptoms and who would undergoing primary PCI were enrolled in the study.The patients randomly received the dual antiplatelet therapy(aspirin of 300 mg and clopidogrel of 600 mg before the PCI, dual group for short) and the triple antiplatelet therapy(aspirin of 300 mg, clopidogrel of 300 mg and intravenous application of tirofiban, triple group for short). Compare the average age, gender ratio, general clinical data, the test results, the distribution of IRA, revascularization time, the number, length and diameter of stents between the two groups. And the thrombus burden grade before PCI, IRA revascularizion before PCI, TIMI grade of blood flow after PCI, the corrected TIMI frame count(CTFC), the myocardial blush grade(MBG), resolution of ST-segment elevation within 1 week, the echocardiogram a week after PCI, and the major adverse cardiac events(MACE) during three months were respectively compared between the two groups for comparing the effects of two antiplatelet treatmenst. MACE was defined as a composite of all cause of death,recurrent myocardial infarction, recurrent target vessel revascularization, recurrent angina and heart failure. Record and compare the bleeding events between the two groups for comparing the safety of two antiplatelet treatments. The clinical datas were also compared between the no reflow group and normal group to analysis the influence factors for no-reflow.Results:1.175 patients with STEMI were enrolled in the study, 81 patients in dual group and94 patients in triple group. There is no significant difference in the average age, the gender ratio, the general clinical data, the biochemical index, between the two groups.2.Compared with that of dual group, the proportion of patients with thrombus burden grade1 of triple group is higher, and the proportion of patients with thrombus burden grade5 is lower. The proportion of patients with IRA revascularizion before PCI is higher. The proportion of coronary flow TIMI 3 grade and MBG 3 grade are respectively higher, and the CTFC is lower(P<0.05).3.The proportion of patients with sum STR completely of triple group is higher than that of dual group on the time of PCI postoperative immediately, 60 min, 24 h, 3 day and 1 week(P<0.05).4.Compared with that of the dual group, the average of LAD and the average LVEDD of triple group are larger, and the EF is lower(P<0.05).5.The incidence of MACE of triple group is less than that of dual group, but the difference is not significant(10.6% vs 22.2%, P>0.05).6.There is no major bleeding complication, and the incidence of minor bleeding events of the two groups are simliar(P>0.05).7. Logistic regression analysis reveales that advance age and application of tirofiban on PPCI upstream are influence factors for no-reflow.Conclusion:1.The triple antiplatelet treatment containing tirofiban, ASA and clopidogrel before PPCI can reduce the thrombus burden, improve the flow of IRA, prevent no-reflow and improve myocardial reperfusion of patients with acute STEMI.2.The triple antiplatelet treatment before PPCI can improve cardiac remodeling,cardiac function of patients with acute STEMI.3.The triple antiplatelet treatment before PPCI has a tendency to reduce the MACE event within 3 months。4. The triple antiplatelet treatment before PPCI does not increase the total bleeding risk of patients with acute STEMI.5. Advance age may be the risk factor of the no-reflow and application of tirofiban on PPCI upstream may be the protective factor for no-reflow.