van't Hof AWJ et al. (2008) Prehospital initiation of tirofiban in patients with ST-elevation myocardial infarction undergoing primary angioplasty (On-TIME 2): a multicentre, double-blind, randomised controlled trial. Lancet 372: 537–546

A report from the Ongoing Tirofiban In Myocardial Infarction Evaluation (On-TIME 2) investigators demonstrates that patients with ST-segment elevation myocardial infarction (STEMI) benefit from early, prehospital treatment with the glycoprotein IIb/IIIa inhibitor tirofiban.

This international, prospective, double-blind trial enrolled patients with acute-onset STEMI who were candidates for percutaneous coronary intervention (PCI). Participants were randomly assigned to receive a 25 µg/kg bolus of tirofiban with a maintenance infusion of 0.15 µg/kg/min for 18 h (n = 491), or matching doses of placebo (n = 493) at first contact with medical personnel. All patients also received aspirin, clopidogrel and unfractionated heparin. Experimental or control drugs were administered in the ambulance in 95% of cases; the median time from symptom onset to medication among these individuals was 75 min. The mean amount of residual ST-segment elevation before (and 1 h after) PCI was significantly lower in patients assigned to tirofiban than in those who received placebo (10.9 versus 12.1 mm, P = 0.028, before PCI and 3.6 versus 4.8 mm, P = 0.003, 1 h after PCI). After 30 days of follow-up, treatment with tirofiban was associated with a reduction in the combined occurrence of death, recurrent STEMI, target-vessel revascularization and emergency use of tirofiban, when compared with placebo (26.0% versus 32.9%, P = 0.02). The incidence of major bleeding did not differ significantly between the two treatment groups.