Thrombin-antithrombin complexes and prothrombin fragment 1+2 in aorto-coronary bypass surgery: relation to graft occlusion.

Graft thrombotic occlusion is a common complication in patients undergoing aorto-coronary bypass surgery. Clotting activation seems to contribute to the thrombotic event. We have determined the plasma concentrations of two hemostatic markers, thrombin-antithrombin (TAT) complexes and prothrombin fragment 1+2 (F 1+2) in 100 patients undergoing revascularization procedures of whom 81 underwent shunt angiography. Angiographically proven graft occlusion was present in 19 patients (23.5%). A significant increase of both parameters was observed immediately after surgery and on postoperative days 1 and 5 (p < 0.001), although a relationship to graft occlusion could not be demonstrated. However, the preoperative TAT concentration was higher in patients developing graft occlusion (p < 0.01). We conclude that there is a marked clotting activation in patients undergoing aorto-coronary bypass surgery, as demonstrated by elevated TAT and F 1+2 concentrations. Preoperative TAT values can be good markers of early graft occlusion.