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 talking with their doctor.
Can Aspirin Prevent a First Heart Attack or Stroke?
The U.S. Preventive Services Task Force (USPSTF) recommends the following:
The use of aspirin for men age 45 to 79 years when the potential benefit due to a reduction in heart attacks outweighs the potential harm due to an increase in gastrointestinal bleeding.
The use of aspirin for women age 55 to 79 years when the potential benefit of a reduction in ischemic strokes outweighs the potential harm of an increase in gastrointestinal bleeding.
The task force does not recommend the use of aspirin to prevent strokes in women younger than 55 years or to prevent heart attacks in men younger than 45.
The task force said there is not enough evidence to assess the benefits and risks of using aspirin to prevent cardiovascular disease in men and women 80 years or older.
How Much Should You Take?
There is controversy over how much aspirin you should take to reduce the chance of a heart attack or stroke. Most doctors advise "low dose" aspirin for people who are at low to moderate risk of a first heart attack or stroke. The usual starting dose is 81 mg per day, the amount in most baby aspirin. The amount of aspirin you should take to prevent a second heart attack or stroke may be higher. It will depend on how old you are, and whether you suffer any side effects from higher doses of the drug.
Be Aware of Risks
While aspirin has been used for decades, a daily dose is not without risks. You should not start taking regular aspirin until you talk with your doctor. People with advanced liver or kidney disease, stomach ulcers, other gastrointestinal diseases, bleeding problems or an allergy to aspirin are at greatest risk from regular aspirin use. But even if you don't have any of these conditions, regular aspirin use may cause gastrointestinal bleeding.
If you are taking regular aspirin to prevent a second heart attack or stroke, tell your doctor right away if you have any side effects. Stomach pain is the most common. You also should tell your dentist or surgeon before you have any surgery (even minor) 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.