Antithrombotic effects of abciximab

The observation that platelet-platelet interaction and thrombosis are ultim ately regulated by the glycoprotein (GP) IIb/IIIa receptor complex, trigger ed the development of agents capable of interfering with this platelet rece ptor complex. Several large clinical trials have demonstrated the effective ness of this class of agents. The first of these agents to show beneficial effects after coronary interventions was the mouse/human chimeric Fab fragm ent antibody c7E3 (abciximab; ReoPro), This study analyzes whether the addi tion of heparin to the GP IIb/IIIa antagonist abciximab would enhance the a ntithrombotic effect. Blood drawn directly from patients on aspirin who und erwent interventional procedures perfused an ex vivo perfusion chamber cont aining a severely injured arterial wall at local theologic conditions of a mildly stenosed coronary artery. Blood was perfused directly from patients at baseline and following administration of heparin, abciximab, or both, Th e antithrombotic effects of the 3 treatments were assessed by reduction of the thrombus formation on the perfused specimens. Thrombus formation at bas eline was not significantly modified by the administration of heparin (13,8 97 +/- 1,316 vs 11,917 +/- 1,519 mu m(2)). Abciximab produced a 58% reducti on in thrombus formation (11,631 +/- 861 vs 4,925 +/- 585 mu m(2); p < 0.00 1). The addition of heparin to abciximab did not further reduce thrombus ar ea versus abciximab alone (5,651 +/- 581 vs 4,925 +/- 585 mu m(2)). Thus, o ur data show that abciximab dramatically decreases mural thrombus formation and that combining heparin with abciximab did not add any additional antit hrombotic effect to abciximab alone. (C) 2000 by Excerpta Medico, Inc.