[A prospective study on the timing of discontinuation of aspirin before coronary artery bypass grafting].

The effects of the timing of discontinuation of aspirin before coronary artery bypass grafting (CABG) on postoperative blood loss and blood requirements were examined in 22 patients undergoing elective CABG, who were randomly assigned into two groups. In Group I (11 patients), aspirin was discontinued two days before the operation and in Group II (11 patients), aspirin was continued up to the operation. The other 40 patients, who did not take aspirin for at least seven days before the operation, served as a control Group. There were no differences in preoperative data including the platelet count and the hemoglobin concentration, nor in operative variables such as operation time, cardiopulmonary bypass duration and aortic crossclamp time among the groups. Although postoperative blood loss (six hours' loss; Group I 218 ml, Group II 183 ml and control Group 172 ml) and red blood cells transfusion requirements were not different among the groups, platelet concentrates transfusion was more frequently required in Group II (54.5%) as compared with control Group (7.5%) and Group I (9.1%). The difference between Group II and the control Group reached statistical significance (p < 0.01), but there was no significant difference between Group I and control Group. This fact suggests that preoperative two days' discontinuation of aspirin works as effectively as seven days' discontinuation.