Background: Tirofiban administered at a bolus dose of 25 mcg/kg is associated with a higher level of platelet inhibition compared to that associated with the standard 10 mcg/kg tirofiban bolus dose. In our previous study on bolus-only glycoprotein IIb/IIIa receptor inhibition during percutaneous coronary intervention (PCI), the eptifibatide bolus-only group demonstrated similar efficacy, but significantly fewer bleeding complications compared to the abciximab bolus-only group.
Objective: To compare the in-hospital outcomes of high-dose (25 mcg/kg) tirofiban bolusonly vs. eptifibatide double bolus-only during PCI. In addition, the degree of platelet inhibition achieved by this novel tirofiban dosing strategy was assessed.
Methods: We retrospectively analyzed 876 consecutive patients who underwent PCI using a single high-dose bolus of tirofiban (25 mcg/kg) or eptifibatide (180 mcg/kg x 2, 10 minutes apart) from January 2003 to August 2005 in a single institution. Patients with ST-segment elevation myocardial infarction were excluded.
Results: The percentage of platelet inhibition was 94% between 3-15 minutes post bolus of 25 mcg/kg of tirofiban. The platelet inhibition dropped to 92% at the end of the procedure (between 20-40 minutes) and to 74% at the time of sheath removal between 2-3 hours. After adjustment for the baseline and procedural characteristics, there was no difference in the composite endpoint of death, myocardial infarction, revascularization and bleeding complications (5.5% in tirofiban group vs. 5.3% in eptifibatide group; p = 0.79).
Conclusion: A single high-dose bolus of tirofiban rapidly achieves profound platelet inhibition and a significant antiplatelet effect is maintained until sheath removal. This dosing during PCI appears safe and compares favorably with eptifibatide bolus-only during PCI.