Association of an activated clotting time < or =250 seconds with adverse event rates after percutaneous coronary intervention using tirofiban and heparin (a TACTICS-TIMI 18 substudy).

Abstract

An inverse relation between the degree of heparin anticoagulation and the subsequent risk of postprocedural thrombotic complications was observed in the era of conventional balloon angioplasty,1,2 but the optimal dose of heparin during percutaneous coronary intervention (PCI) using newer interventional equipment and glycoprotein IIb/IIIa receptor inhibition has not been well defined. Increased rates of bleeding were noted in the Evaluation of c7E3 for the Prevention of Ischemic Complications (EPIC) trial in patients treated with abciximab and heparin with a target activated clotting time (ACT) of 300 to 350 seconds.3 Later studies using glycoprotein IIb/IIIa receptor inhibitors4–7 found that bleeding complications during coronary angioplasty and stent implantation could be attenuated with early sheath removal and adjusted low-dose heparin. This evidence led to the recommendation of using a goal ACT of 200 to 250 seconds during interventional procedures when heparin and glycoprotein IIb/IIIa receptor inhibitors are used.8,9 Although they minimize bleeding complications, reduced doses of heparin may be associated with a higher risk of adverse events, and a safe and effective lower boundary to the optimal ACT after the administration of tirofiban has not been well defined.10 We hypothesized that ACTs ≤250 seconds during PCI with tirofiban and heparin anticoagulation would be associated with increased adverse events at 30 days.