Risk of bleeding after prehospital administration of high dose tirofiban for ST elevation myocardial infarction.

Background: In most patients with ST-elevation myocardial infarction (STEMI), antiplatelet drugs are already administrated in the ambulance, before hospital admission. We investigated the safety of prehospital initiation of a high dose of the glycoprotein IIb/IIIa inhibitor tirofiban on top of aspirin, clopidogrel and heparin.

Methods: It concerns a sub-analysis of the On-TIME 2 trial. 1398 patients were enrolled and 1275 patients (91.2%) had clinical follow up. Non CABG-related bleeding was defined according to the TIMI criteria. Logistic regression was used to determine predictors of 30-day bleeding. The independent association between bleeding and mortality (30-day and 1-year) was evaluated using Cox proportional Hazard models.

Results: Bleeding (major or minor) was observed in 47 patients (3.7%), with only 13 patients (1%) with major bleeding. The strongest independent determinants of bleeding were age (OR 1.05, 95% CI 1.01-1.08, p=0.011), Killip class >1 at admission (OR 2.5, 95% CI 1.2-5.3, p=0.020) and intra aortic balloon pump (IABP) use (OR 4.2, 95% CI 1.6-11.1, p=0.003). High dose tirofiban was not an independent predictor of bleeding (OR 1.7, 95% CI 0.9-3.2, p=0.116). Bleeding was associated with an increased risk of 30-day mortality (HR 5.5, 95% CI 1.6-7.8, p<0.001) and one-year mortality (HR 3.2, 95% CI 1.4-7.2, p=0.005).

Conclusion: Prehospital use of high dose tirofiban is safe and associated with a low risk of bleeding. Age, Killip class >1, IABP use, but not high dose tirofiban are independent determinants of bleeding in STEMI patients. Bleeding is independently associated with 30-day and 1-year mortality.