CHANGES OF ANTITHROMBIN-III VALUES, PROTH ROMBIN FRAGMENT-1-III COMPLEX AFTER IMPLANTATION OF CORONARY PALMAZ-SCHATZ STENTS(2 AND THROMBIN ANTITHROMBIN)

To detect changes in the clotting parameters antithrombin III (AT III) , prothrombin-fragment 1 + 2 (F 1 + 2) and thrombin-antithrombin-III-c omplex (TAT) after implantation of Palmaz Schatz stents, coagulation w as monitored at standardized time points in 35 patients for 10 days. A ll patients were anticoagulated using a combination of heparin, phenpr ocoumon, and acetyl salicylic acid. Heparin therapy was guided by APTT levels (normal range 25-35 s), which were still within the therapeuti c range (median 49.6 s (25 %/75 % percentiles 41.6/54.4) on day 10. Si multaneous oral anticoagulation was found to be effective on day 8 on average (INR median 2.24 (1.93/2.50)). The AT III activity dropped sig nificantly (p < 0.0001) after a heparin loading dose of 15,000 IU duri ng stenting. As the heparin dose was reduced on the following days, AT III levels increased significantly (p < 0.0001) during the observatio n time. There was a highly significant (p < 0.001) negative correlatio n between AT III and heparin levels. On days 4 and 5 F 1 + 2 values we re significantly (p < 0.001 and p < 0.05) higher than on the day of st enting (median 1.07 (0.90/1.31) 1.13 nmol/l and 1.06 (0.85/1.23) nmol/ l vs. 0.97 (0.69/1.15) nmol/l) and dropped during anticoagulation. F 1 + 2 levels showed a significant negative correlation (p < 0.0005) wit h APTT values. TAT values showed no significant changes during the obs ervation period. In one patient who developed subacute stent thrombosi s on day 5, the level of F 1 + 2 20 min prior to stent occlusion was f ound to be less than the median of all other patients for this specifi c day (0.98 nmol/l vs. 1.07 (0.84/1.23) nmol/l). Summarizing our resul ts, there are significant changes of AT III und F 1 + 2 levels during anticoagulation in the first days after coronary stenting. However, F 1 + 2 values are not able to predict subacute stent thrombosis in the individual case.