SUMMARYThe purpose of this study was to determine the clinical outcomes of abciximab combined with the low molecular weight heparin (LMWH), dalteparin, in high-risk percutaneous coronary intervention (PCI) patients with acute myocardial infarction (AMI). A total of 140 high-risk PCI patients with AMI were divided into 2 groups: unfractionated heparin (UFH) with abciximab (group I: 70 patients, 58.7 ± 10.5 years), and dalteparin with abciximab (group II: 70 patients, 59.6 ± 9.8 years). Major adverse cardiac events (MACE) during hospitalization and at 4 years after PCI were examined. Baseline clinical characteristics, laboratory findings, echocardiography parameters, and baseline angiographic characteristics were not different between the 2 groups. The incidence of thrombotic total occlusion lesions was 62.9% in both groups. Procedural success was achieved in 91.4% in group I and 90.0% in group II. Bleeding and hemorrhagic events were not different between the 2 groups. No significant intracranial bleeding was observed in either group. The incidence of in-hospital MACE was 7 (10.0%) in group I and 4 (5.7%) in group II. Four-year clinical follow-up was performed in 97% of the patients. Four years after PCI, death occurred in 6 (8.6%) patients in group I and in 7 (10.0%) in group II. MI occurred in 4 (5.7%) and 4 (5.7%), target vessel revascularization (TVR) in 23 (32.9%) and 16 (22.9%), and bypass surgery in 3 (4.3%) and 1 (1.4%), respectively. Overall, a MACE occurred in 33 (47.1%) patients in group I and in 26 (35.1%) patients in group II (P = 0.23). The long-term clinical outcome with dalteparin combined with abciximab may be comparable to that of UFH plus abciximab in high risk PCI patients with AMI. (Int Heart J 2006; 47: 821-831)