Patients will be randomized in a 1:1:1 ratio to 1 of 3 treatment groups: A, B, and C. Group A will receive MCC-135 4.5 mg/kg/48 hours; Group B will receive MCC-135 9.0 mg/kg/48 hours; and Group C will receive placebo/48 hours. Three hundred thirty patients with a TIMI flow grade of 0/1 are required to complete the study. Because patients will be enrolled and will receive study medication prior to assessment of TIMI flow, it is expected that at least 414 patients may need to be randomized in order to obtain the required 330 qualified patients. All randomized patients will receive 48 hours of study medication, with ongoing assessments during this period, and will have follow-up assessments on Days 3, 4, 5, 30, and 180 as described below, regardless of preoperative TIMI flow grade.