Platelet retention in coronary artery bypass surgery with and without a heart-lung machine - Cause of thrombosis in coronary artery bypass surgery

The aim of this study was to examine platelet function after coronary arter y bypass grafting (CABG) with and without the use of extracorporeal circula tion (ECC). Sixteen male patients scheduled for CABG with (n = 8) and witho ut (n = 8) ECC were included in the study. Platelet retention, as measured with a glass-bead retention test, was examined daily during the first posto perative week. Von Willebrand factor (VWF), ristocetin co-factor (Rcof) and prothrombin fragment (PF 1 + 2) were analyzed the day after the operation. We found a significant increase (p < 0.0001) in platelet retention during the first postoperative week after CABG. There was a tendency (not statisti cally significant) towards a more pronounced increase in the group operated on without ECC, This increase occurred despite the fact that all patients were treated with aspirin (75 mg daily) from the first postoperative day. T he median time to maximal postoperative platelet retention was 2 days. In 3 patients platelet retention increased to more than 6 times the basal level .