RESUMEN
The aim of this study was to investigate the effect of early or delayed warfarin administration with unfrac-tionated heparin [UFH] on coagulation parameters in pulmonary thromboembolism [PTE]. This study was performed between November 2006 and July 2007. Thirty-three patients with PTE were sequentially slotted to early [n = 16] and delayed [n = 17] warfarin treatment groups. In the early group, both UFH infusion and warfarin were started simultaneously and in the delayed group, warfarin was added [1-3 days later] based on when partial thromboplastin time reached the therapeutic level with UFH. The proteins C and S, D-dimer, hematocrit levels, and platelet counts for all patients were studied prior to treatment and 6.24, and 48 h after warfarin treatment. In order to determine the overall effect of early and delayed warfarin treatment on clot formation, a thromboelastogram was performed simultaneously. In both groups, a similar chronological decrease in protein C levels reaching maximum at 24 h with warfarin treatment was observed. However, intragroup or intergroup decreases in protein S levels were not different. On thromboelastogram, INTEM and EXTEM clotting times were significantly prolonged chronologically, but this prolongation was not different between groups. The suppressor effect of warfarin on proteins C and S in the early period of double anticoagulant treatment did not appear to aggravate the risk of thrombosis in patients with PTE in whom warfarin was started simultaneously with UFH