High Bolus Tirofiban vs Abciximab in Acute STEMI Patients Undergoing Primary PCI – The Tamip Study

BACKGROUND: Primary percutaneous coronary intervention (PCI) has been shown to be an effective therapy for patients with acute myocardial infarction (MI). Glycoprotein (GP) IIb/IIIa receptor blockers reduce thrombotic complications in patients undergoing PCI. Most available data relate to Reopro, which has been registered for this indication. GP IIb/IIIa reduce unfavorable outcome in U/A and non ST-elevation myocardial infarction (STEMI) patients. Only few studies focused on high dose Aggrastat for STEMI patients in the emergency department (ED) before PCI. The aim is to increase the patency during the time awaiting coronary angioplasty in patients with acute MI. OBJECTIVES: To study the effect of upfront high bolus dose (HDR) of tirofiban on the extent of residual ST segment deviation 1 hour after primary PCI and the incidence of TIMI 3 flow of the infarct-related artery (IRA). MATERIALS AND METHODS: A randomized, open label, single center study in the ED. A total of 90 patients with acute ST-elevation MI, diagnosed clinically by ECG criteria (ST segment elevation of >2 mm in two adjacent ECG leads), and with an expectation that a patient will undergo primary PCI. Patients were aged 21-85 years and all received heparin 5000 u, aspirin 160 mg, and Plavix 600 mg. Patients were divided in two groups (group I: triofiban high bolus vs group II: Reopro) with 45 patients in each group. In group I, high bolus triofiban 25 mcg/kg over 3 min was started in the ED with maintenance infusion of 0.15 mcg/ kg/min continued for 12 hours and transferred to cath lab for PCI. Patients in group II were transferred to cath lab, where a standard dose of Reopro was given with a bolus of 0.25 mcg/kg and maintenance infusion of 0.125 mcg/kg/min over 12 hours. RESULTS: ST segment resolution and TIMI flow were evaluated in both groups before and after PCI. Thirty-five patients (78%) enrolled in group I and 29 patients (64%) in group II had resolution of ST segment (P-value 0.24). Twenty-one patients (47% group I) vs 23 patients (51% group II) with P-value 0.83 achieved TIMI 0 flow. Twenty-four patients (53% group I) compared with 22 patients (49% group II) with P-value 0.83 had TIMI 1 to 3 flow before PCI. TIMI 3 flow was achieved in 40 patients (89% group I) compared with 38 patients (84% group II) with P-value 0.76. CONCLUSION: In this study there was a trend toward better ST segment resolution and patency of IRA (i.e., improved TIMI flow) in patients given high bolus dose Aggrastat in the ED. Larger studies are needed to confirm this finding.