The monoclonal antibody c7E3 (ReoPro) is a highly selective inhibitor of platelet aggregation that binds to the fibrinogen receptor (GP IIb/IIIa) on the surface of platelets and leads to a dose-dependent, nearly complete inhibition of platelet aggregation. The clinical value of c7E3 to reduce ischemic events after PTCA in addition to heparin and aspirin has been demonstrated in the EPIC-, EPILOG-, and CAPTURE-trial. In these studies, c7E3 was associated with an increased bleeding risk after the coronary intervention. The DTREO-Trial (German trial with c7E3) was designed as a prospective study to investigate the clinical safety of c7E3 in the daily routine of a cath lab. From April 1995 through September 1996 520 patients were enrolled at 30 German sites. c7E3 was mainly used in patients with acute coronary syndromes (55% unstable angina Braunwald Class I-III and C; 28% in acute myocardial infarction) and in patients with complex coronary lesions (AHA/ACC classification type B and C lesion in 84% of the study group). In 51% of the interventions a stent was implanted (25% in bailout-situations and in 26% as an elective intervention) and c7E3 was used as an adjunctive to prevent sub-acute stent thrombosis. The incidence of "major" bleeding events (TIMI-classification) was less frequent in this study as in the EPIC-trial and comparable to the results of the EPILOG- and CAPTURE trial. In conclusion this study confirms the positive risk profile of c7E3 in patients undergoing high-risk percutaneous revascularization procedures.