Abstract 6022: The Effect of Pre-Hospital Tirofiban on Early Stent Thrombosis in STEMI Patients Undergoing Primary PCI
Objective The aim of this analysis was to assess the effect of pre-hospital initiation of high-dose (HD) tirofiban on the incidence of early stent thrombosis (ST) in patients undergoing primary PCI for acute myocardial infarction.
Methods Patients were randomized to HD tirofiban or no tirofiban in the ambulance on top of 600 mg clopidogrel, 500 mg aspirin and 5000 IU unfractionated heparin. ST was defined according to the Academic Research Consortium definitions of “definite” and “probable” stent thrombosis.
Results A total of 1073 out of 1398 patients (76.8%) underwent primary PCI with stent implantation. Overall, “definite” or “probable” ST occurred in 39 patients (3.6%) at 30 days. The incidence in the no tirofiban or placebo group was 5.2% (28/537; 27 definite and 1 probable) versus 2.1% (11/536; 10 definite and 1 probable) in the HD tirofiban group (p=0.006). In univariate analysis, predictors of ST were no pre-hospital initiation of HD tirofiban (p=0.006), previous myocardial infarction (p=0.016), TIMI risk score >3 (p=0.027) and TIMI major bleeding (p=0.002). By multivariate analysis, no pre-hospital initiation of HD tirofiban (Odds ratio [OR] 2.54, 95% confidence interval [CI] 1.21–5.32; p=0.013), previous myocardial infarction (OR 3.32, 95%-CI 1.35– 8.18; p<0.01), and TIMI major bleeding (OR 8.40, 95%-CI 2.24 –31.46; p=0.002) were independent predictors of early ST. Thirty day mortality was significantly higher in those with ST (10.3% versus 1.7%, p<0.001).
Conclusion Pre-hospital initiation of high dose tirofiban reduces the 30-day incidence of stent thrombosis in STEMI patients treated with primary PCI. Early stent thrombosis was associated with poor outcome.