Comparative Study Of TIMI3Grade Flow After Different Reperfusion Strategies On Myocardial Infarction Size In Patients With Acute ST-segment Elevation Myocardial Infarction

Objectives: This randomized, prospective, active-controlled clinicalcomparative study was designed to explore the TIMI3grade flow afterdifferent reperfusion strategies on myocardial infarction size in patients withacute ST-segment elevation myocardial infarction (STEMI).Methods: A total of242STEMI patients (203males,39females) meetingthe2007ACC/AHA diagnostic criteria of STEMI within12hours fromsymptom onset (aged56.5±11.73years old) were enrolled from February2010to August2011in our hospital. A dose of300mg aspirin and300mgclopidogrel were given immediately after the patients were diagnosed asSTEMI. Intravenous thrombolysis treatment was administered in163casesand emergency percutaneous coronary intervention (PCI) was performed in79cases according to qualified physicians. Intravenous administration ofreteplase was injected as10U+10U for over two minutes, with30-minuteinterval. Emergency coronary angiography (CAG) was performed90-120minutes after thrombolysis, and the there were94patients achieved TIMI3grade flow in infarction related artery (IRA). Rescue PCI was performed inpatients whose IRA was beyond TIMI3grade flow. Together with79patientstreated by primary PCI, TIMI3grade flow was achieved in101cases afterPCI, with slow reflow in2cases and death in1case. A total of44patientswere excluded because no emergency CAG was performed, elective PCI, oronly drug treatment were administered, patients’ refuse, or loss of follow-up.Venous blood samples were mornitered at admission,4hours,8hours,12hours,16hours,20hours,24hours,36hours,48hours,60hours,72hoursafter PCI, respectively to measure the level of CK-MB, and area under the curve for CK-MB was evaluated. Enoxaparin was administrated for7-10daysin both groups. Other medications including aspirin, clopidogrel, statins,ACEIor ARB,β-blocker, nitrates were administered according to the current clinicalguidelines. Baseline clinical characteristics, CTFC grade, myocardial blushgrade, duration of hospitalization, IRA patency time and myocardial infarctionsize, the major adverse cardiovascular events (MACE) and the heart functionfollowed up for3months were compared between the two group. Myocardialinfarction size was calculated by IMAGEJ, and SPSS13.0was used in stasticanalysis. A P value＜0.05was defined as stastically significant difference.Results:1There were195patients was enrolled into our study (164male and31female, average age was58.50±10.42years old), and all the eligible patientswere divided into two group: the thrombolysis group and the emergency PCIgroup.2Comparison of basic clinical characteristics: There was no significantdifference in the two groups including age, gender distribution, hypertension,type2diabetes, hyperlipidemia, history of smoking, time from onset totreatment (382.67±172.20min vs.398.25±169.82min, P＞0.05), and IRApatency time (61.32±15.26min vs.68.45±17.23min, P＞0.05). There wasno significant difference in the IRA distribution between two groups (P＞0.05). There were65%of patients in the reperfusion after thrombolysis groupwith residual stenosis≥50%,33%residual stenosis≥75%, and2%without ameaningful residual stenosis. There was no significant difference in CTFCgrade (32.63±11.30vs.33.25±10.53，P＞0.05) and the rate of myocardialblush grade3(85%vs.83%，P＞0.05).3Comparison of the myocardial infarction size: The myocardial infarctionsize in72hours is smaller in the reperfusion after thrombolysis group than theemergency PCI group, but there is no significant difference between the twogroups (4760.90±1349.38vs.5014.38±1243.37，P=0.67).4Comparison of the incidence of MACE followed up for3months: NoMACE occurred in both groups after3-month followe-up. 5Comparison of the heart function followed up for3months: There was nosignificant differences in left ventricular end diastolic volume (LVEDV)(131.21±20.39vs.133.78±22.14ml), left ventricular end systolic volume(LVESF)(71.34±16.32vs.74.25±15.62ml), and left ventricular ejectionfraction (LVEF)(55.62±8.12%vs.54.38±7.84%)(all P＞0.05).Conclusion:1The myocardial infarction size in72hours of the patients with STEMIachieving the coronary TIMI3grade flow after early thrombolysis is smallerthan that after emergency PCI，however, no significant difference was found.2There was no significant difference in the incidece of MACE and the heartfunction followed up for3months in patients with STEMI after earlythrombolysis and emergency PCI.