Application Of Tirofiban In Patients Presenting With Acute ST-segment Elevation Myocardial Infarction Undergoing Direct Percutaneous Coronary Intervention

Objectives: To demonstrate platelet factor 4(PF4), platelet aggregationrate(PAR),the cumulative incidence of 7 days and 30 days composite endpoint and angiographic outcomes(TIMI flow grade,corrected TIMI framecount,TIMI myocardial perfusion grade) of tirofiban in patients presentingwith acute ST-segment elevation myocardial infarction(STEMI) undergoingdirect percutaneous coronary intervention(d-PCI), and its complications, toevaluate its efficacy and safety furtherer.Methods: 78 patients presenting with STEMI(chest pain＜12h)undergoing d-PCI who were administrated tirofiban were enrolled tirofibangroup(n=40),patients without tirofiban were enrolled control group(n=38) atcardiology department of the second Xiangya Hospital of Central SouthUniversity from 2005 June to 2007 January.Tirofiban group receivedintravenous tirofiban as 10μg/kg in 3 minutes followed by a 36-hour infusionof 0.15μg/kg/min and control group received intravenous placebo at 10-30minutes before d-PCI. All patients received intravenous heparin and oralADP receptor antagonists(clopidogrel) and aspirin. Compare the variation ofPF4,PAR,the cumulative incidence of 7 days and 30 days composite endpoint(death, recurrent myocardial ischemic, reinfarction and target vesselrevascularization),angiographic outcomes(TIMI flow grade,corrected TIMIframe count,TIMI myocardial perfusion grade) and its complications:bleeding and thrombocytopenia in two groups.Results: PF4 of patients presenting with STEMI was a significantincrease,and was not significantly different in two groups befored-PCI[(49.82±6.43)ng/ml versus (52.08±6.38)ng/ml P＞0.05],and PF4 was lower in the tirofiban group than in the control group at 12 and 24 hours afterd-PCI[(14.13±3.51)ng/ml versus (17.01±4.65)ng/ml P＜0.05;(1.22±0.85)ng/ml versus (1.73±1.13)ng/ml P＜0.05,respectively].The level of PF4 washigher in the slow flow group than in the normal flow group neither tirofibangroup nor control group at preoperation,12 and 24 hours after d-PCI(P＜0.05).After administration tirofiban,PAR had a significant decrease(58.43％±7.63％vs 12.43％±8.27％P＜0.001) in the tirofiban group. The cumulativeincidence of 7 days composite end point was of no difference(7.5％vs21.1％,P=0.086)in two groups,the cumulative incidence of 30 days compositeend point was significantly decreased in the tirofiban group(10.0％vs28.9％,P=0.034).Angiographic outcomes demonstrate after d-PCI a greaterpercentage of patients had TIMI flow grade(TFG)Ⅲ(87.5％vs68.4％,P=0.041),corrected TIMI frame count(cTFC) of patients was lower(22.75±3.06 vs 25.50±6.76,P=0.026),TIMI myocardial perfusiongrade(TMPG) O/I was significantly less frequent(10.0％vs 28.9％,P=0.034) inthe tirofiban group than in the control group. Bleeding complications occurredmore frequently in tirofiban group(22.5％vs 5.3％,P=0.048). Minor bleedingwas 7 cases, mostly at the arterial access site. Major bleeding was 2 cases whotransfused. There were not intracranial hemorrhage and thrombocytopenia intwo groups.Conclusions: PF4 is of significant increase in patients presenting withSTEMI, and PF4 is significantly decreased in the tirofiban group at 12 and24 hours after d-PCI. The level of PF4 was higher in the slow flow groupthan in the normal flow group neither tirofiban group nor controlgroup.Tirofiban inhibits significantly PAR of patients presenting withSTEMI. The cumulative incidence of 7 days composite end point is of no difference in two groups,which was possibly related to no enoughpopulation;the cumulative incidence of 30 days composite end point is lowerin the tirofiban group than in the control group.Tirofiban improves obviouslyangiographic outcomes of patients presenting with STEMI undergoingd-PCI.Bleeding rates are excessive in the tirofiban group, minor bleeding is7 cases,major bleeding is 2 cases who transfuse.But there is of nointracranial hemorrhage and thrombocytopenia in two groups.Tirofibanimproves apparently clinical outcomes and angiographic outcomes ofpatients presenting with STEMI undergoing d-PCI,which is possibly relatedto tirofiban inhibiting platelet aggregation and activation,releasing increaseof PF4 and blocking the final common pathway tothrombogenesis.So,tirofiban is effective and safe,and is a new choice ofantiplatelet therapy during perioperation in patients presenting with STEMIundergoing d-PCI.