Why do some doctors advise you to take baby asprin for chest pains?

Baby aspirin. Doctors often advise patients to take baby Aspirin daily to help prevent clot formation in the coronary arteries. Aspirin suppresses platelet aggregation and can decrease the chance of a heart attack due to a blood clot forming.
Because it works. Aspirin is a blood thinner and has an anti-inflammatory effect which has been associated with better outcome in case of heart ischemia.