Clinical experience with routine activated coagulation time monitoring during elective PTCA

Intracoronary thrombosis is an im portant factor in the pathogenesis of acute complications during percutaneous coronary interventions. The activated coagulation time (ACT) is a simple, reproducible bedside test that has become standard as the means of monitoring the anticoagulant effect of heparin during these procedures. To determine if ACT-adjusted heparin dosing reduces the procedure-related complications of elective PTCA, 1200 patients who underwent nonemergent percutaneous transluminal coronary angioplasty (PTCA) between January 1, 1988 and February 26, 1992 were studied.Methods/Results: Two groups were identified based on the use of empirical heparin dosage (group 1, before July 1, 1990) vs. ACT-guided heparin administration strategies (group 2, after July 1, 1990). Group 2 patients were older, had worse left ventricular function, and were more likely to have experienced a prior myocardial infarction than patients in group 1. Patients in group 1 were more likely to have chronic stable angina and a positive exercise test, while group 2 patients were more likely to be undergoing PTCA for post-myocardial infarction (MI) angina. Angiographie characteristics were also consistent with a higher risk profile in group 2 than in group 1 (92.7% vs. 83.4%, p < 0.001). Postprocedural complications, including abrupt closure and late closure, were lower in group 2 patients. The incidence of abrupt vessel closure was decreased by approximately 50% (6.9% vs. 3.5%, p < 0.025), and delayed vessel closure was significantly reduced by over 60% (3.2% vs. 1.0%, p < 0.05). There were no differences in femoral artery complications between the two specified groups.Conclusions: ACTguided heparin therapy during percutaneous coronary interventions decreases acute and delayed vessel closure, even in the presence of clinical and angiographic characteristics that would predict a higher incidence of these events.

by Stephen J. Voyce1, Louis I. Heller1, Bonnie H. Weiner1 , Lawrence I. Laifer1, Lawrence L. Greenwald1, Kevin T. Carey1 and Richard C. Becker1

Division of Cardiology, Interventional Cardiology and Thrombosis Research Center, Clinical Trials Section, University of Massachusetts Medical School, Worcester, MA