Participants in this study who suffer chest pain will be treated with a single enteric coated aspirin 325 mg instead of the current treatment without aspirin. Participants will then be tested to confirm that they had a heart attack by EKG (a test to measure the electrical activity of the heart) and blood tests (5ml of blood) will be drawn every 8 hours to detect enzymes that are released from the heart due to the heart attack. Blood samples will also be examined for platelet number.