Impact of final activated clotting time after transradial coronary stenting with maximal antiplatelet therapy

The optimal value of activated clotting time (ACT) during percutaneous coronary intervention (PCI) with unfractionated heparin remains controversial. No data are available on the relation between the ACT at the end of the procedure (final ACT) and the clinical outcomes after transradial PCI and maximal antiplatelet therapy. By dividing the final ACT values in tertiles, we analyzed the ischemic and bleeding events in 1,234 consecutive patients with acute coronary syndrome recruited in the EArly Discharge after Transradial Stenting of CoronarY Arteries (EASY) trial. All patients were pretreated with aspirin and clopidogrel. After radial sheath insertion, patients received 70 IU/kg unfractionated heparin. Abciximab was given before the first balloon inflation. The median final ACT value was 312 seconds (interquartile range 279 to 344). At 30 days, the rate of major adverse cardiac events, including death, myocardial infarction, and target vessel revascularization, from the lower to upper tertiles was 4%, 4%, and 2%, respectively (p = 0.16), and the rate of major bleeding was 2%, 1% and 0.7%, respectively (p = 0.20). During the 3 years of follow-up, the incidence of myocardial infarction was less in the tertile with the greatest ACT value (>330 seconds) than in the other 2 tertiles (4%, 8%, and 8%, respectively; p = 0.038). Troponin-T and creatine kinase-MB release after PCI indicated that the effect was related to periprocedural myonecrosis protection. After adjustment for baseline and procedural differences, a final ACT of >330 seconds remained associated with a 47% relative reduction in myocardial infarction (odds ratio 0.53, 95% confidence interval 0.29 to 0.93, p = 0.024). Death and target vessel revascularization remained similar in all tertiles for < or =3 years. In conclusion, with the combination of aspirin, clopidogrel pretreatment, and abciximab, a final ACT value of >330 seconds appears protective against peri-PCI myonecrosis, and this benefit was maintained for < or =3 years. With a transradial approach and maximal antiplatelet therapy, greater ACT values did not correlate with an increased risk of bleeding.