Prevention by ticlopidine of platelet consumption during extracorporeal circulation for heart surgery and lack of effect on operative and postoperative bleeding.

We studied the effects of ticlopidine, a platelet antiaggregant drug, on platelet consumption during and after extracorporeal circulation (ECC) and on the operative and postoperative blood loss in a double-blind, placebo-controlled trial on 20 patients who underwent open-heart surgery for implantation of a valvular prosthesis. We monitored the changes in platelet count during and after ECC, the need for platelet transfusions to compensate for excessive consumption, and the operative and postoperative blood loss. We also followed the cephalin-kaolin time, the prothrombin time, the fibrinogen level, the fibrin/fibrinogen degradation products, and the euglobulin lysis time. Ticlopidine effectively reduced operative and post-ECC thrombopenia and prolonged the bleeding time. Apart from these changes, no differences in coagulation tests were observed between the ticlopidine-treated group and the placebo group. No side effects were observed. There was no significant difference between the groups concerning operative and postoperative blood loss, indicating that ticlopidine does not induce a hemorrhagic diathesis. Ticlopidine therapy may be of value during the first postoperative days because it prevents clotting on valvular prosthesis and complications such as systemic embolization. However, more trials and controlled studies are needed before such therapy can be recommended for routine use.