THE EFFECT OF PREOPERATIVE RECOMBINANT-HUMAN-ERYTHROPOIETIN THERAPY ON PLATELETS AND HEMOSTASIS IN PATIENTS UNDERGOING CARDIAC-SURGERY

In a double-blind, randomized, placebo-controlled trial we evaluated t he effects of the administration of recombinant human erythropoietin ( 5 x 500 U epoetin beta/kg body weight intravenously over a 14-day peri od before surgery) in patients undergoing cardiac surgery and in whom autologous blood donation was contraindicated on platelet count, plate let distribution width, mean platelet volume (MPV), and certain hemost aseologic parameters. All patients received 3 x 70 IU heparin/kg per d ay s. c. from 2 days before operation. No thromboembolic events were a ssociated with epoetin beta therapy during the study period. The throm bocytic parameters showed no significant changes in the placebo group before surgery, and the preoperative hematocrit increase in the epoeti n beta group was accompanied with an MPV drop (in contrast to the know n MPV rise in recombinant human erythropoietin-treated patients with u remia) by a mean of 0.85 fl and a platelet distribution width rise by 3.3% without a significant change in platelet count. In the epoetin be ta group the coagulation time (K) of thromboelastogram (TEG) showed an increase from 4.8 to 5.4 minutes by the seventh study day and after t he initiation of heparin therapy a further increase to 7.5 minutes. Th e higher preoperative K increase in the epoetin beta group may partly be a result of the MPV reduction, because smaller platelets are less r eactive, a fact underlined by the negative correlation between the pre operative changes of MPV and reaction time of TEG (r = -0.58, p = 0.01 48). In contrast, in the placebo group the K of TEG increased only aft er the start of heparin therapy (from 5.1 to 6.4 minutes). The signifi cant drop in MPV in the epoetin beta group and the higher increase in K of TEG and the other investigated hemostatic parameters do not sugge st any increased thromboembolic risk during the preoperative epoetin b eta therapy. Therefore this treatment seems to be a safe way for incre asing mean hematocrit by approximately 0.06 within the normal range an d reducing the homologous blood requirement in patients undergoing ele ctive cardiac surgery.