• The composite of all-cause mortality or complications of MI (rehospitalization or emergency department visit for Coronary Heart Failure, cardiogenic shock, or resuscitated ventricular fibrillation occurring > 48 hours after randomization) at 90 days. [ Time Frame: 90 days ] [ Designated as safety issue: Yes ]
  

• Complications of MI and all-cause mortality through 90 days; Percent of Subjects with ST-segment resolution > 70% from baseline at 60 to 90 minutes following randomization; Incidence of non-intracranial and intracranial bleeding through discharge/day 7. [ Time Frame: 7 days or discharge, whichever is first ] [ Designated as safety issue: Yes ]
  

The purpose of this medical research study is to determine whether abciximab given in combination with reteplase, before patients have a coronary intervention (a standard treatment where a catheter is inserted into the heart artery to get blood flowing past the clot), is safe and effective in the treatment of heart attacks compared to only abciximab given during coronary intervention. This medical research study will also help determine if the combination of abciximab and reduced dose reteplase will decrease the risk of death, and reduce complications of a heart attack at 90 days compared to abciximab alone which is a standard treatment. Patients will receive either abciximab and reteplase or abciximab alone. Safety evaluations will be performed at specified intervals throughout the study and will consist of laboratory tests, vital signs (such as blood pressure), physical examinations and the occurrence and severity of adverse events as well as other study specific procedures.

Patients will receive either abciximab and reteplase or abciximab and placebo into a vein in their arm for up to 12 hours.