Effects Of Bivalirudin On Infarct Size In Patients With Acute ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Objectives:To explore effects of bivalirudin on infarct size in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.Methods:A total of82STEMI patients (55males,27females) were selected from the patients with primary PCI from October2011to February2013in our hospital. The patients were all evaluated before the operation, and then were randomly divided into two groups:bivalirudin group (n=40) and heparin group (n=42). All the patients were required to sign with consents. A dose of300mg aspirin and300mg clopidogrel were given in the department of emergency. Bivalirudin was intravenously administered a bolus of0.75mg/kg before the operation, followed by an infusion of1.75mg/kg/h to the end of the procedure (less than4hours), maintaining the dose of0.2mg/kg/h up to16-20hours (according to the conditions of patients and experiences of operators) in the bivalirudin group. Three thousand units of heparin was injected before the operation in the heparin group, and another seven thousand units of heparin was given before vascularization, keeping ACT of250-350seconds. All the clinicians have a qualification of primary PCI, adopting a routine PCI technic. Aspirin100mg/d, clopidogrel75mg/d and statins were given by oral in the two groups, besides ACEI or ARB, and/or β-blocker, and/or nitrates. Enoxaparin was administrated for7days after operation in the two groups. Baseline clinical characteristics, duration of the disease, IRA, door to balloon time, TIMI grade, CTFC, myocardial blush grade, the level of perioperative BNP, myocardial infarct size and left ventricular ejection fraction (LVEF) at a week and a month were compared between bivalirudin group and heparin group. Myocardial infarction size was calculated by IMAGEJ, and SPSS19.0was used in stastic analysis.Results:There were no significant differences between the two groups in baseline clinical characteristics before primary PCI (P>0.05), including the time of onset, the IRA, the door to balloon time. The IRAs were opened successfully in both of the two groups. Although the percentage of TIMI grade3achieved after PCI in bivalirudin group was higher than heparin group, there was no significant difference between the two groups (85.7%vs.76.5%, P=0.36). The CFTC of IRA in bivalirudin group was lower than heparin group (30.4±8.5vs.35.7±9.2,P=0.01). While the percentage of myocardial blush grade3of IRA after PCI in bivalirudin group was higher, but no significant difference was found in the two groups (81.6%vs.74.5%,P=0.54). The level of baseline BNP was not significantly different between the two groups (60.9±18.5vs.63.2±17.7,P=0.57). The level of BNP at the twenty-fourth hour after the operation was lower in the bivalirudin group, there was no significant difference between the two groups (136.2±42.3vs.145.8±51.5,P=0.36). The myocardial infarction size is smaller in bivalirudin group than heparin group, but there is no significant difference between the two groups (4446.0±1400.4vs.4805.7±1600.3,P=0.28). LVEF at a week was not significantly different between the two groups (45.4±3.7vs.43.7±4.6,P=0.12). LVEF at a month was also not significantly different in bivalirudin group and heparin group (47.2±4.1vs.45.4±5.0,P=0.08).Conclusion:Application of bivalirudin could improve blood flow and reperfusion in patients with STEMI undergoing primary PCI. There was a trend that the myocardial infarction size was smaller in bivalirudin group, however, bivalirudin can not reduce infarct size significantly.