 This randomized, double-blind, placebo-controlled study will evaluate the efficacy and safety of RO4905417 in patients with non ST-elevation myocardial infarction Non-STEMI undergoing percutaneous coronary intervention PCI. Patients will be randomized to receive an intravenous infusion of either 5 mgkg RO4905417 or 20 mgkg RO4905417 or placebo before PCI. Follow-up will be for 4 months. 