THE ROLE OF THE ACTIVATED CLOTTING TIME ( ACT) IN ANTICOAGULATION ASSESSMENT AFTER PTCA

Accurate heparina anticoagulation assessment is important to prevent c omplications (hemorrhage, thrombotic coronary occlusion) during and af ter coronary angioplasty (PTCA). Paired ACT-, aPTT- and prothrombin ti me (PT) measurements have not been studied after PTCA using a high dos e heparin management. Fur that reason we analyzed in 150 consecutive p atients (115 m., 35 f,, 61 +/- 10 V.) immediately after PTCA and at th e time of arterial sheath removal aPTT- (Neothromtin, Behring), PT- (T hromborel S. Behring) and ACT- (HR-ACT, HemoTec) values after applicat ion of 20 000 U of heparin (5000 U intravenous, 15 000 U intracoronary ) followed by a heparin-infusion (15 000-25 000 U/24 h). Immediately a fter PTCA in all patients a aPTT above the uppper limit of > 180 s was found. The average postprocedural ACT was 330 +/- 82 s. Only 9 patien ts showed an ACT below 200 s. All coronary reocclusions (n = 3) immedi ately after PTCA occurred in this group, Arterial sheaths were removed 13 +/- 3 h after PTCA. The incidence of minor peripheral bleeding com plications at that time was 21% and was related to the anticoagulation level. Major bleeding complications requiring transfusion were noted in only one case, Our findings suggest that after high dose hepariniza tion for PTCA the ACT test provides a reliable and broad range for the assessment of heparin anticoagulation. In contrast to the aPTT the AC T is ideally suited to determine the dosage of heparin infusion and th e time of arterial sheath removal after PTCA. ACT measurements art: su perior to aPTT measurements in heparin anticoagulation assessment duri ng and direct after PTCA.