ANTIPLATELET THERAPY WITH TICLOPIDINE INCREASES BLOOD LOSS AND TRANSFUSION IN CORONARY BYPASS SURGERY

Abstract

Introduction. Similar to aspirin, ticlopidine causes an irreversible, therefore long lasting, non competitive inhibition of platelet function. Whereas aspirin acts on platelet cyclo-oxygenase and thus inhibits thromboxane formation, ticlopidine blocks ADP-induced alpha-granule secretion and impedes the exposure of fibrinogen binding sites. Particularly the platelet adhesion caused by endothelial injury and sheer stress seems susceptible to this treatment. It prevents adverse thrombotic events especially after coronary dilatation and stent implantation [1]. The aim of this study was to assess the perioperative blood management in ticlopidine-treated patients. Methods. Registered data since 1997 of all patients with coronary heart disease were analyzed in an observational study. Blood loss from chest tube (after 6, 12, 24h and in total) and allogeneic blood requirement were noted. Mann Whitney U-test and chi-square test were used for statistics. Median and interquartile range (IQR) were calculated and differences considered significant, when p<0.05. Results. Among 1166 CABG patients, 96 were on ticlopidine medication and compared to the 1070 remaining patients. 83% of the ticlopidine patients, compared to 48%, were on aspirin less than 5 days before surgery. Demographic data were comparable, only urgent operations were more frequent (28% vs. 9%; p<0.001) and NYHA classification slightly more adverse in the ticlopidine group. Table 1Table 1Excessive blood loss (>1500 ml/24h) was observed more frequently in the ticlopidine group (14% vs. 5%, p<0.001). Perioperatively 62% of the ticlopidine patients received allogeneic blood compared to 45% (p<0.001). Packed red cell administration was significantly higher in the ticlopidine group (2 units (3) vs. 0 (2), p<0.001). Postoperative blood loss was increased by 30% at any time interval. Figure 1Figure 1Discussion. In ticlopidine-treated patients increased perioperative blood loss and transfusion needs must be dealt with. Usually the drug cannot be withdrawn due to the obvious benefit, nor can surgery be postponed in unstable cases. Efforts should be made to identify excessive bleeders in advance by laboratory tests. The possibility of therapeutic intervention perioperatively should be considered.