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 the effects of the administration of recombinant human erythropoietin (5 x 500 U epoetin beta/kg body weight intravenously over a 14-day period before surgery) in patients undergoing cardiac surgery and in whom autologous blood donation was contraindicated on platelet count, platelet distribution width, mean platelet volume (MPV), and certain hemostaseologic parameters. All patients received 3 x 70 IU heparin/kg per day s. c. from 2 days before operation. No thromboembolic events were associated with epoetin beta therapy during the study period. The thrombocytic parameters showed no significant changes in the placebo group before surgery, and the preoperative hematocrit increase in the epoetin beta group was accompanied with an MPV drop (in contrast to the known MPV rise in recombinant human erythropoietin-treated patients with uremia) 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 beta 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 the initiation of heparin therapy a further increase to 7.5 minutes. The higher preoperative K increase in the epoetin beta group may partly be a result of the MPV reduction, because smaller platelets are less reactive, a fact underlined by the negative correlation between the preoperative changes of MPV and reaction time of TEG (r = -0.58, p = 0.0148). In contrast, in the placebo group the K of TEG increased only after the start of heparin therapy (from 5.1 to 6.4 minutes). The significant drop in MPV in the epoetin beta group and the higher increase in K of TEG and the other investigated hemostatic parameters do not suggest any increased thromboembolic risk during the preoperative epoetin beta therapy. Therefore this treatment seems to be a safe way for increasing mean hematocrit by approximately 0.06 within the normal range and reducing the homologous blood requirement in patients undergoing elective cardiac surgery.