Abstract 17650: The Effect of Early Pre-hospital Initiation of High Bolus Dose Tirofiban on Angiographic Characteristics Before and After Primary PCI: Results of a Sub-analysis of the On-TIME 2 Trial
Background: Initial reperfusion before mechanical intervention in STEMI is associated with improved clinical outcome. It is unknown whether pre-hospital administration of high bolus dose (HBD) Tirofiban on top of dual antiplatelet therapy improves initial and final reperfusion. Aim of this sub-analysis was to assess the effect of early initiation of HBD Tirofiban on angiographic outcome before and after primary PCI in STEMI patients.
Methods: This is a post-hoc analysis in the subgroup of patients who underwent primary PCI in the On-TIME 2 trial, a multicentre, controlled randomised trial of HBD tirofiban or placebo given in the ambulance in STEMI patients. Study medication was given on top of aspirin, heparin, and high-dose (600 mg) clopidogrel. All angiographic parameters, including quantitative angiography (QCA) was performed in an angiographic corelab by 2 investigators blinded to treatment assignment and clinical outcome.
Results: Primary PCI was performed in 1203/1398 patients (86.1%), 601 (50.0%) patients were randomised to placebo or no HBD Tirofiban and 602 (50.0%) patients to HBD Tirofiban. An occluded infarct related vessel (TIMI 0 or 1 flow) at initial angiography was less often present in the HBD Tirofiban group as compared to the placebo group (43.7% vs 53.0%, p=0.001). HBD Tirofiban also reduced initial thrombus burden (45.3% vs 52.2%, p=0.03). These data were confirmed by QCA which showed a significant reduction in diameter stenosis and a increase of minimal luminal diameter before PCI in the HBD Tirofiban group. After PCI, HBD Tirofiban was associated with a trend toward a lower corrected TIMI frame count and a lower incidence of no-reflow or distal embolisation (table).
Conclusion: In this post-hoc analysis of patients undergoing primary PCI, early initiation of HBD Tirofiban reduced initial thrombus burden, improved initial patency of the infarct related vessel and improved angiographic reperfusion after PCI as assessed by corrected TIMI frame count.
- © 2010 by American Heart Association, Inc.