Clinical Experience with Routine Activated Coagulation Time Monitoring During Elective PTCA.

Background: Intracoronary thrombosis is an important 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 nomemergent percutancous transluminal coronary angioplasty (PTCA) between January 1, 1988 and February 26, 1992 were studied. Methodsl
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. Angiographic 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 6017,(3.2% vs. 1.0%, p < 0.05). There were no differences in femoral artery complications between the two specified groups.
Conclusion: ACT-guided 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.