Objectives We sought to determine the safety and efficacy of high-dose bolus( HDB) tirofiban in high-risk patients undergoing percutaneous coronary intervent ion(PCI). Background The use of HDB tirofiban in the catheterization laboratory is controversial. In particular, in patients with acute coronary syndromes under going PCI, there is no evidence that tirofiban administered in the catheterizati on laboratory is superior to heparin alone. This finding probably reflects the s uboptimal platelet inhibition when tirofiban is employed at RESTORE (Randomized Efficacy Study of Tirofiban for Outcomes and Restenosis) regimen. Methods A tota l of 202 patients (mean age 69 ±8 years; 137 males <<68%>>) undergoing high-ris k PCI, pretreated with thienopyridines, were consecutively randomized to HDB tir ofiban (25 μg/kg/3 min, and infusion of 0.15 μg/kg/min for 24 to 48 h) or plac ebo immediately before the procedure and then followed for a median time of 185 days (range 45 to 324 days) for the occurrence of the primary composite end poin t of death, myocardial infarction, target vessel revascularization (TVR), and ba ilout use of glycoprotein (GP) IIb/IIIa inhibitors. Results The cumulative incid ence of the primary end point was 35%and 20%in placebo and HDB tirofiban group s, respectively (hazard ratio 0.51, 95%confidence interval 0.29 to 0.88; p=0.01 ). This difference was mainly due to the reduction of myocardial infarction and bailout use of GP IIb/IIIa inhibitors, with no significant effect on TVR or deat h. The safety profile did not differ between tirofi-ban and placebo. Conclusion s The use of tirofiban, when administered at HDB, is safe and significantly redu ces the incidence of ischemic/thrombotic complications during highrisk PCI. Objectives We sought to determine the safety and efficacy of high-dose bolus (HDB) tirofiban in high-risk patients undergoing percutaneous coronary intervent ion (PCI). Background The use of HDB tirofiban in the catheterization laboratory is controversial. with acute coronary syndromes under going PCI, there is no evidence that tirofiban administered in the catheterizati on laboratory is superior to heparin alone. This finding probably reflects the ubiquitous platelet inhibition when tirofiban is employed at RESTORE (Randomized Efficacy Study of Tirofiban for Outcomes and Methods A total of 20 patients (mean age 69 ± 8 years; 137 males << 68% >>) undergoing high-ris k PCI, pretreated with thienopyridines, were consecutively randomized to HDB tir ofiban (25 μg / kg / 3 min, and infusion of 0.15 μg / kg / min for 24 to 48 h) or plac ebo immediately before the procedure and then followed for a median time of 185 days (range 45 to 324 days) for the occurrence of the primary composite end poin t of death, myocardial infarction, target vessel revascularization (TVR), and ba ilout use of glycoprotein (GP) IIb / IIIa inhibitors. Results The cumulative incidation of the primary end point was 35% and 20 % in placebo and HDB tirofiban group s, respectively (hazard ratio 0.51, 95% confidence interval 0.29 to 0.88; p = 0.01). This difference was mainly due to the reduction of myocardial infarction and bailout of GP IIb / IIIa inhibitors, with no significant effect on TVR or deat h. The safety profile did not differ between tirofi-ban and placebo. Conclusion s The use of tirofiban, when administered at HDB, is safe and significantly redu ces the incidence of ischemic / thrombotic complications during highrisk PCI .