Purpose: To evaluate the possible role played by activation of the coagulation system in the early occlusion of grafts in patients subjected to aortocoronary bypass.
Patients and methods: This study includes 30 patients subjected to coronary revascularization surgery. The plasma rates of thrombin-anti-thrombin complexes (TAT) and 1+2 prothrombin fragments (F1+2) were measured before and after surgery. The studies were performed by enzyme immunoassay techniques. Selective angiography was performed in every patient on the 10th day after surgery. Descriptive statistics, Student's t test and Mann-Whitney U test were used for comparison of means ans statistical analysis.
Results: Occlusive lesion was shown by angiography in 15 of the 30 patients. The TAT and F1+2 levels showed a statistically significant increase (p less than 0.001) along the postoperative period, without any correlation regarding the presence or absence of occlusion. The preoperative concentration of TAT was significantly higher in patients with thrombotic occlusion (p less than 0.05).
Conclusions: 1) Marked activation of the coagulation system is present in patients subjected to coronary revascularization surgery. 2) The pre-operative determination of TAT may be of value for predicting early graft occlusion.