Even as in-hospital treatment for heart attacks has greatly improved, aspirin is the only anti-platelet treatment routinely used in the U.S. for heart attacks before patients can get to the hospital. Disaggpro was designed to change that, as it can be administered in several pre-hospital settings for rapid treatment of ST-segment elevation (STEMI) heart attacks. The priority in treating STEMI heart attacks is opening the coronary artery as soon as possible after the onset of symptoms to prevent death or irreversible heart damage. About 40% of heart-attack patients have STEMIs, the most severe form of heart attack, in which blood flow to a portion of the heart is almost always cut off by a blood clot. Eligible STEMI patients were enrolled at home, in the ambulance or in a hospital emergency department.