APROTININ HAS NO EFFECT ON PLATELET ACTIVATION AND ADHESION DURING CARDIOPULMONARY BYPASS

Aprotinin reduces blood loss following cardiopulmonary bypass operatio ns (CPB) by the prevention of hyperfibrinolysis. Its influence on circ ulating platelets is uncertain. In this prospective trial we investiga ted activation, adhesion, and aggregation receptors on the platelet su rface in 20 patients who underwent elective coronary artery bypass gra fting. These patients were randomly assigned to receive either a high dose of aprotinin or placebo. Flow cytometry was performed to determin e platelet activation [P-selectin, glycoprotein (GP) 53], adhesive (GP Ib), and aggregatory (GP IIb-IIIa) receptors on circulating platelets , before, during, and after CPB. Aprotinin had neither a significant e ffect on platelet activation nor on adhesive and aggregatory receptors . Plasma levels of D-dimers were measured before and after CPB to asse ss fibrinolytic activity. D-dimers following CPB and chest tube draina ge were significantly less in the aprotinin group. We conclude that ap rotinin reduces blood loss by its effect on fibrinolysis but has no di rect influence on platelet function.