A number of studies have found that people who have suffered a heart attack can reduce the chance of a second attack by taking aspirin regularly. Aspirin works by preventing platelets in the blood from clumping together. This reduces the chance that a blood clot will form in an artery that is already clogged by a plaque.
The American Heart Association recommends that people who have had a heart attack, unstable angina, ischemic stroke or transient ischemic attacks (known as TIAs or "little strokes") consider taking aspirin regularly after consultation with their doctor.
If you are taking regular aspirin to prevent a second heart attack or stroke, you should tell your doctor immediately if you have any side effects, most commonly, stomach pain. You also should tell your dentist or surgeon before undergoing minor surgery or dental work because aspirin may increase the likelihood of bleeding during the procedure. The tendency to bleed persists for up to 10 days after the drug is stopped.