Effect of early, pre-hospital initiation of high bolus dose tirofiban in patients with ST-segment elevation myocardial infarction on short- and long-term clinical outcome.

OBJECTIVES The purpose of this trial was to study the effect of a high bolus dose (HBD) of tirofiban on clinical outcome in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). BACKGROUND The On-TIME 2 (Ongoing Tirofiban In Myocardial infarction Evaluation 2) placebo-controlled, double-blind, randomized trial showed that early administration of HBD tirofiban in the ambulance improves ST-segment resolution in patients with STEMI undergoing primary percutaneous coronary intervention. The effect of early tirofiban treatment on clinical outcome is unclear. METHODS The On-TIME 2 trial consisted of 2 phases: an open-label phase, followed by a double-blind, placebo-controlled phase. STEMI patients were randomized to either HBD tirofiban or no tirofiban (phase 1) or placebo (phase 2) in addition to aspirin, heparin, and high-dose clopidogrel. The protocol pre-specified a pooled analysis of the 2 study phases to assess the incidence of major adverse cardiac events at the 30-day follow-up and on total mortality at the 1-year follow-up. RESULTS During a 3-year period, 1,398 patients were randomized, 414 in phase 1 and 984 in phase 2. Major adverse cardiac events at 30 days were significantly reduced (5.8% vs. 8.6%, p = 0.043). There was a strong trend toward a decrease in mortality (2.2% vs. 4.1%, p = 0.051) in patients who were randomized to tirofiban pre-treatment, which was maintained during the 1-year follow-up (3.7% vs. 5.8%, p = 0.08). No clinically relevant difference in bleeding was observed. CONCLUSIONS Early, pre-hospital initiation of HBD tirofiban, in addition to high-dose clopidogrel, improves the clinical outcome after primary percutaneous coronary intervention in patients with STEMI. (Ongoing 2b/3a inhibition In Myocardial infarction Evaluation; ISRCTN06195297).