Intravenous enoxaparin versus unfractionated heparin in unselected patients undergoing percutaneous coronary interventions: the Zurich enoxaparin versus unfractionated heparin in PCI study (ZEUS)

AIMS: To evaluate the efficacy and safety of intravenous enoxaparin as an alternative to unfractionated heparin (UFH) as antithrombotic therapy in unselected patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: Eight hundred and seventy-six (876) consecutive eligible patients undergoing PCI were prospectively randomised to either intravenous enoxaparin 0.75 mg/kg or dose-adjusted UFH in this open-label study that was prematurely stopped due to slow recruitment. Randomisation was stratified on elective PCI or PCI for acute coronary syndrome (ACS). The primary endpoint was a combination of death, myocardial infarction, unplanned target vessel revascularisation and major bleeding at 30 days. Secondary endpoint was a composite of major and minor bleeding and thrombocytopenia < 50x109. The primary endpoint of intravenous enoxaparin did not differ from those of UFH (5.5% vs. 7.0%, p=ns) whereas safety endpoints were reduced with enoxaparin compared to UFH (9.9% vs. 20.0%, p<0.001). Among 229 (26%) patients presenting with ACS, the incidence of both, the primary and secondary endpoints, was lower with enoxaparin as compared to UFH (1.8% vs. 12.9% and 14.2% vs. 31%, p<0.001 and p=0.003, respectively). CONCLUSIONS: Due to the premature halting of the study and the low event rate, these data are observational only, and no definite conclusion could be made concerning efficacy and safety of intravenous enoxaparin as an alternative to UFH in unselected patients undergoing PCI.