Analysis Of The Factor Related To No-reflow In Patients With St-segment Elevation Myocardial Infarction After Primary PCI Undering Different Thrombus Burden

Background : ST-segment Elevation Myocardial Infarction(STEMI)is a severe acute disease.The pathogenesis of STEMI is mostly attributed to the rupture or erosion of unstable intracoronary plaque,which even progress into the formation of the thrombus leading to the complete occlusion of coronary artery and result in myocardial ischemia eventually.Opening of infarct related artery in time effectively can improve myocardial perfusion and save large areas of dying cardiomyocytes,reduce myocardial infarct size and protect cardiac function,which is the best way to improve the prognosis.Percutaneous coronary intervention(PCI)is known as a timely and effective way to open occlusion coronary artery and improve myocardial perfusion.However,some patients showed a poor myocardial perfusion after PCI,naming the no-reflow phenomenon,which may be ascribed to the thrombo-embolism on the level of microcirculation of culprit vessel.Objective: Therefore,this research is based on the thrombolysis in myocardial infarction(TIMI)flow grade less than two grade as an index of no-reflow in patients with STEMI,aming to analyze the factors related to the no-reflow phenomenon during the primary PCI therapy undering different thrombus burden.Methods: From January 2015 to January2018 in the Hebei General Hospital,102 cases diagnosed as ST-Segment Elevation Myocardial Infarction whom received intracoronary administration of tirofiban or recombinant human prourokinase during primary PCI retrospectively were adopted.All of the patients were divided into non-reflow group(TIMI flow grade ≤ 2)and normal flow group(TIMI flow grade 3).The non-reflowgroup has 41 cases.The normal flow group has 61 cases.All of the patients were divided into high and low thrombus burden states,according to the infarction related artery thrombus burden.We hope to exploer the factors related with the occurrences of no-relow in the patients undering different thrombus burden.Results:1.1 In both high and low thrombus burden we found that gender,age,history of hypertension,diabetes mellitus,hyperlipidemia,angina pectoris,previous history of myocardial infarction,Ischemic stroke,previous history of PCI,history of hypotensive drugs,smoking,alcohol consumption history,current myocardial infarction site,KILLIP class what have nostatistical significant differences(P>0.05)between normal flow group and no-reflow group.1.2 Using single factor analysis found that between the nomal flow group and no reflow group infarction related artery preoperative TIMI flow grade,myocardial ischemia time and intraoperative application for tirofiban or rh-pro UK had significant differences(P<0.05).1.3 According to the principle of multivariate Logistic regression analysis,We found that myocardial ischemia time(B=0.015,OR=1.015,95%CI 1.003-1.027,P=0.011)is a risk factor for the occurrence of no-reflow during primary PCI with high thrombus burden.However,the infarction related artery having slow blood flow preoperativly(B=-2.175,OR=0.114,95%CI 0.014-0.893,P=0.039)using of rh-pro UK during PCI were the protective factors for the nomal flow,reducing the occurrence of no-reflow in high thrombus burden group.1.4 There was no significant difference in preoperative TIMI flow grade distribution between patients with rh-pro UK or tirofiban during PCI in high thrombus burden group(P=0.904).The TIMI flow grade after PCI was significantly higher in patients whom use rh-pro UK during PCI than tirofiban(P=0.048).1.5 The no reflow events occurred significantly lower in patients withslow arterial blood flow than whom without blood flow befter PCI in high thrombus burden group(P=0.001).2.1 According to the principle of multivariate Logistic regression analysis,We found that myocardial ischemia time(B=0.006,OR=1.006,95%CI 1.000-1.013,P=0.045)is a risk factor for the occurrence of no-reflow during primary PCI with low thrombus burden.However,the infarction related artery having slow blood flow preoperativly(B=-1.798,OR=0.166,95%CI 0.039-0.712,P=0.016),using of tirofiban during PCI were the protective factors for the nomal flow,reducing the occurrence of no-reflow in low thrombus burden group.2.2 There was no significant difference in preoperative TIMI flow grade distribution between patients with rh-pro UK or tirofiban during PCI in low thrombus burden group(P=0.981).The TIMI flow grade after PCI was significantly higher in patients whom use tirofiban during PCI than rh-pro UK(P=0.019).2.3 The no reflow events occurred significantly lower in patients with slow arterial blood flow than whom without blood flow befter PCI in high thrombus burden group(P=0.028).3 The myocardial ischemia time is 357.50±87.02 min in high thrombus burden group,however,the myocardial ischemia time is 246.24±96.72 min in low thrombus burden group.The differernce has statistical significance.4 The thrombus burden grade of infarction related artery is increasing with myocardial ischemia time prolonging in STEMI patients(P<0.001).Conclusion:1 The thrombus burden grade of is increasing with myocardial ischemia time prolonging in STEMI patients.2 The myocardial ischemia time is a risk factor for the occurrence of no-reflow phenomenon during primary PCI with different thrombus burden.3 The infarction related artery having slow flow preoperativly,using of rh-pro UK during PCI may reduce the occurrence of no-reflow in highthrombus burden group.4 The infarction related artery having slow flow preoperativly,using of tirofiban during PCI may reduce the occurrence of no-reflow in low thrombus burden group.