The Efficacy And Safety Of Domestic Bivalirudin In Patients With ST-segment Elevation Myocardial Infarction Underging Transradial Primary PCI

Objective:To investigate the safety and efficacy of bivalirudin in patientswith ST-segment elevation myocardial infarction (STEMI) who wereperformed primary percutaneous coronary intervention (PCI) within12hoursafter onset of symptoms.Methods:A total of70pateints with ST STEMI elevation acutemyocardial infarction, who were performed coronary angiography (CAG) andPCI within12hours after the onset of symptoms, including48men and22women,average age57.39±8.35(≤75) years old, were enrolled into this studyfrom February2011to February2013. They were randomly assigned intobivalirudin (group A, n=35) group and unfractionated heparin plus tirofiban(group B, n=35) group.Bivalirudin was administered as an intravenous bolus of0.75mg/kg, thenmaintained of1.75mg/kg/h during PCI,at last followed by an infusion of0.2mg/kg/h till24hours after the first bolus. The activated clotting time (ACT)was detected after5min of the bolus. If the ACT was less than225s, the extradose (0.3mg/kg) would be needed. Heparin was administered as anintravenous bolus of100IU/kg (maximum10000IU). If the ACT was lessthan225s, the extra dose (20U/kg) would be needed. Heparin wascontinuously pumped with subsequent boluses, in order to maintain the ACT200s--300s till24hours after the first bolus. Tirofiban was administered asan intravenous bolus of5μg/kg before PCI and followed by an infusion of0.075μg/kg/min for24hours.Concomitant medications:1. A loading dose of clopidogrel300mg andaspirin300mg were administered before catheterization, followed byclopidogrel75mg and aspirin100mg orally every day for at least1year.2. When both antithrombin agents were discontinued, low molecular weightheparin (5000u,Bid) will be routinely used for7days. Other adjuvant drugs,such as nitroglycerin,ACEI, β-blocker, statin and so on, were administered.Routine indicators of blood, such as blood routine test, renal function test,hepatic function test, glucose levels, fibrinogen test, electrolytes test, creatinekinase (CK-MB) and troponin I (cTnI) concentration, were performed. Thesafty and effectiveness index were compared between the two groups,including the incidence of adverse clinical event after primary PCI during24hours and30days, ACT, the success rate of PCI, the TIMI flow grade andTIMI myocardial perfusion grade (TMPG). The total adverse clinical eventsincluded major adverse cardiac events(MACE), major bleeding (accordingto REPLACE-2bleeding standard and BARC bleeding standard) and theincidence of thrombocytopenia. The major adverse cardiac events weredefined as: malignant arrhythmia, severe heart failure, reinfarction, targetvessel revascularization, and cardiac death. Thrombocytopenia was defined asthe platelet count <l00×109/L after the application of the drugs. The patientswere divided into low-risk subgroup, and high-risk subgroup according toTIMI risk score for STEMI patients and the incidence of adverse clinicalevents were compared among different subgroups.Statistical analysis was performed with the Statistical Package for theSocial Sciences (SPSS; version19.0) software. Categorical variables werepresented as a percentage and compared with Chi-square tests or Fishersexact probability, while continuous variables were presented as means±standard deviation and compared with Student’s t-test. The difference wasconsidered significant if P <0.05.Results:1Comparion of the clinical data at baseline between the two groups:There were no significant differences between the two groups at baselinesuch as age, sex, body mass index, hypertension,diabetes, hyperlipidemia,coronary heart disease family history, smoking history, myocardial infarctionhistory, PCI treatment history, the time from onset to admission, TIMI risk score and anemia.And there were no significant differences between the twogroups at baseline in routine indicators of blood such as renal function,creatinine clearance rate, hemoglobin, platelet counts, erythrocyte counts,hepatic function, glucose levels, fibrinogen, electrolytes, creatine kinase(CK-MB) and troponin I (cTnI) concentration.2Comparison of the efficacy between the two groups.Coronary angiography showed no significant differences in infarct-related artery (IRA) and TIMI flow grade between group A and group B.There was no significant difference in ACT peak value（330.68±102.08vs.301.57±123.27, P=0.29）,success rate of PCI (94.3%vs.91.4%,P=1.00)between the two groups. There were no significant differences inthe proportion of TMPG≥2(85.7%vs.82.9%, P=0.94)and the ratio of TIMIflow grade3(94.3%vs.91.4%, P=1.00）after PCI between the two groups.3Comparison of the safety between the two groups.During24hours after PCI, there were no significant differences in totaladverse clinical events (5.7%vs.11.4%, P=0.67), and major bleeding (5.7%vs.11.4%, P=0.67)(according to REPLACE-2bleeding grading standards)between the two groups. There was a case with severe bleeding in group B.During30days follow-up, there were no significant differences in totaladverse clinical events (5.7%vs.14.3%, P=0.43), and major bleeding (5.7%vs.14.3%, P=0.43)(according to REPLACE-2bleeding grading standards)between the two groups. According to BARC bleeding standard,ompared withgroup B, group A had a significantly lower rate of bleeding (11.4%vs.34.3%,P=0.04). There were no significant differences in major adversecardiovascular events (0.0%vs.2.9%, P=1.000), thrombocytopenia and stentthrombosis between group A and group B.4Comparison of the incidence of total adverse clinical events amongdifferent subgroups according to TIMI risk score for STEMI.There was no significant difference in low-risk subgroup (14.3%vs.23.1%, P=0.649) between the two groups. In high-risk subgroup, compared withgroup B, group A had a significant lower rate of bleeding (according to BARC bleeding standard)(9.5%vs.40.1%, P=0.046).Conclusion:Domestic bivalirudin results in similar efficacy and the major adversecardiovascular events in patients with acute STEMI undergoing primary PCIas compared with heparin plus tirofiban, while it is significantly reduces30-day incidence of bleeding. Especially, domestic bivalirudin moresuitable for high-risk patients with safty.