TIrofiban Given in the Emergency Room before Primary Angioplasty - TIGER-PA

Description:

The goal of the TIrofiban Given in the Emergency Room before Primary Angioplasty (TIGER-PA) study was to evaluate the safety, feasibility, and utility of early tirofiban administration before planned primary angioplasty in patients presenting with acute myocardial infarction (MI).

Hypothesis:

Early administration of tirofiban will be safe and feasible, and will improve angiographic outcomes in patients undergoing primary angioplasty for acute MI.

Study Design

Study Design:

Patients Screened: 157
Patients Enrolled: 100
Female: 38

Patient Populations:

Clinical symptoms of acute MI with initial chest pain onset in the past 12 hours; suitable candidates for PCI; and had an ECG with ≥0.1 mV ST-segment elevation in ≥2 contiguous leads or documented new left bundle branch block.

Exclusions:

Cardiogenic shock, use of an intra-aortic balloon pump, and known bleeding diathesis.

Primary Endpoints:

Initial TIMI flow grade, corrected TIMI frame counts, and TIMI myocardial perfusion grade.

Secondary Endpoints:

30-day death, re-MI, or rehospitalization.

Drug/Procedures Used:

Patients were randomized open-label to "early" administration of tirofiban in the emergency room (n=50) versus "late" administration of tirofiban in the catheterization laboratory after diagnostic angiography (n=50). All patients received a tirofiban dose of 10 mg/kg bolus over three minutes, followed by 0.15 µg/kg/min for 24 hours. Patients in the "early" arm received a heparin bolus of 70 U/kg followed by 5 U/kg/h, and those in the "late" arm received a 100 U/kg bolus and a maintenance dose of 10 U/kg/h.

Concomitant Medications:

If a coronary stent was placed, clopidogrel (300 mg orally, and 75 mg/day for at least 28 days) or ticlopidine (500 mg orally, and 250 mg twice/day for at least 28 days) was administered.

Principal Findings:

Time from door to tirofiban was 26 minutes longer in the late arm than the early arm (p<0.001), but there was no difference in door to balloon time (p=NS). Initial thrombolysis in myocardial infarction (TIMI) grade 3 flow occurred more frequently in the early tirofiban arm versus the late administration arm (32% vs. 10%, p=0.007). Another measure of coronary flow, the corrected TIMI frame count (CTFC), was also better with early administration (66 frames vs. 44 frames, p=0.005). The TIMI myocardial perfusion grade occurred more frequently in the early administration arm (32% vs. 6%, p=0.001). There was no difference in the post-percutaneous coronary intervention (PCI) TIMI flow grade, CTFC, or TIMI myocardial perfusion grade. There was no difference in the rate of 30-day death (2% vs. 2%, p=NS), recurrent MI (0% vs. 2%, p=NS), rehospitalization (4% vs. 6%, p=NS), or the composite of these events (6% vs. 10%, p=NS; all comparisons early vs. late administration). There was also no difference in major bleeding (2% vs. 2%, p=NS) or minor bleeding (10% vs. 6%, p=NS).

Interpretation:

Among patients with acute MI planned to undergo primary PCI, early administration of tirofiban in the emergency room was associated with improved angiographic outcomes compared with late administration of tirofiban in the catheterization laboratory. There were no additional bleeding complications associated with the earlier administration of tirofiban, which was received an average of 33 minutes prior to PCI. The composite clinical end point did not reach significance; however, the study was not powered to detect a difference in clinical events (n=100). Larger trials are needed to determine if the initial angiographic benefit will translate into a reduction in clinical events. The ongoing TITAN/TIMI 34 trial will examine a similar hypothesis with eptifibatide, another glycoprotein IIb/IIIa inhibitor.

References:

Lee DP, Herity NA, Hiatt BL, et al. Adjunctive platelet glycoprotein IIb/IIIa receptor inhibition with tirofiban before primary angioplasty improves angiographic outcomes: results of the TIrofiban Given in the Emergency Room before Primary Angioplasty (TIGER-PA) pilot trial. Circulation. 2003;107:1497-501.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Invasive Cardiovascular Angiography and Intervention, EP Basic Science, Novel Agents

Keywords: Cysteine, Myocardial Infarction, Platelet Aggregation Inhibitors, Heparin, Coronary Disease, Fibrinolytic Agents, Emergency Service, Hospital, Electrocardiography, Angioplasty, Tyrosine, Percutaneous Coronary Intervention, Chest Pain, Peptides, Catheterization, Bundle-Branch Block


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