Timing of coronary stent thrombosis in patients treated with prophylactic tirofiban

Background. Acute and subacute stent thromboses (ASST) are the major thromb otic complications of coronary stenting. The time course of ASST seems to b e related to the type of antithrombotic therapy (four days in patients trea ted with aspirin and coumadin compared to 12 hours with the use of aspirin and ticlopidine). In this report, we compared the timing of ASST in patient s treated with aspirin, ticlopidine/clopidogrel, heparin and tirofiban with that in patients treated with the same drugs but without tirofiban. Methods. Retrospective analysis of the Hermann intervention database betwee n January 1997 and October 1999 was performed. We identified 13 patients wh o required reintervention in the first week after a successful coronary ste nting (greater than or equal to 1 stent). Four patients were treated with t irofiban (Group 1) and 9 were not (Group 2). Results. The median time from stent deployment to ASST was 7 hours (interqu artile range, 2.5-33 hours) in group 2 compared to 84.5 hours (interquartil e range, 56-124.5 hours) in group 1. The mean time from stent deployment to ASST was 90.3 +/- 43.1 hours in group 1 versus 12.8 +/- 15.3 hours in grou p 2 (p = 0.0005). All episodes of ASST occurred greater than or equal to 3 days in patients treated with tirofiban. whereas they occurred in the first 2 days in all patients not treated with tirofiban. Conclusion. Prophylactic tirofiban treatment delays the time to stent throm bosis after successful coronary artery stent implantation for more than two days. Patients at high risk for stent thrombosis treated with short-acting glycoprotein IIb/IIIa platelet receptor inhibitors may warrant close follo w-up during the first week after stenting.