IS THERE A PHASE OF HYPERCOAGULABILITY WHEN APROTININ IS USED IN CARDIAC-SURGERY

To determine a possible phase of hypercoagulability after the use of h igh-dose aprotinin, a prospective randomized double-blind study was pe rformed. Twenty patients undergoing aortocoronary bypass surgery were investigated, a placebo group P (n = 10) was compared to an aprotinin group A (n = 10). Examining parameters of thrombin activation and fibr inolysis, we found during extracorporeal circulation - under continuou s aprotinin infusion - a significant inhibition of thrombin activation and fibrinolysis in the aprotinin group (thrombin-antithrombin-III-co mplexes: 95 +/- 23 mug/l, d-dimers: 448 +/- 60 ng/ml, plasminogen acti vity: 33 +/- 3%, plasminogen activator inhibitor: 98 +/- 14 U/ml) comp ared to the placebo group (thrombin-antithrombin-III-complexes: 143 +/ - 13 mug/l, d-dimers: 2755 +/- 430 ng/ml, plasminogen activity: 125 +/ - 15%, plasminogen activator inhibitor: 10 +/- 4 U/ml). In contrast, a fter stopping the aprotinin infusion - from the end of extracorporeal circulation until the morning of the first postoperative day - strong thrombin activation took place in the aprotinin group (d-dimers increa sed from 472 +/- 90 to 1607 +/- 140 ng/ml), while in the placebo group a decrease could be registered. At this time, the fibrinolysis was st ill reduced in the aprotinin group (plasminogen activity: 48 +/- 6% vs 85 +/- 16% in the placebo group). In conclusion, interference with th e thrombohemorrhagic balance induces hypercoagulability after the use of high-dose aprotinin, with elevated levels of thrombin-antithrombin- III-complexes, d-dimers, and plasminogen and a decreased level of plas minogen activator inhibitor. In our opinion, it is necessary to preven t this counter-regulation. Because of the predominant activation of th rombin during this period, heparin might be an effective therapy, prov ided that its cofactor antithrombin III is kept in the normal range.