Officially, aspirin has been recommended for most people who have already had a heart attack or stroke to prevent another heart attack or stroke. This is called secondary prevention. For these people, the benefits of taking aspirin daily outweigh the potential risks. One of the main risks of taking an aspirin daily is the risk of developing major bleeding. These types of bleeds usually happen in the stomach in the form of a bleeding stomach ulcer or in the brain in the form of a hemorrhagic (bleeding) stroke. Evidence shows that most people who have had a heart attack or stroke (caused by a clot) are far more likely to prevent another one than suffer from a major bleed when they take a baby aspirin (81mg) daily.
So we know that most people who have had a heart attack or stroke (caused by a clot) will prevent another one when they take a baby aspirin daily. What about people who have never had a heart attack or stroke? Should they take aspirin daily? Taking aspirin daily to prevent a FIRST heart attack or stroke is called primary prevention. For these people, aspirin will prevent about 1 first heart attack or stroke per 1000 people per year. Unfortunately, it will also cause a similar number of bleeds. This is why only certain people should be taking aspirin to prevent a first heart attack or stroke.
In general the guidelines recommend an 81mg aspirin daily for PRIMARY prevention for men over the age of 45 and women over 55 IF they have cardiovascular risk factors such as high blood pressure or high cholesterol AND are NOT at a high risk for bleeding. For people with diabetes, the recommendations have just changed. It used to be that daily aspirin was recommended for all people with diabetes over the age of 40, or even sooner if they had cardiovascular risk factors. The American Diabetes Association has recently changed this recommendation. It is now recommended that diabetic men over 50 and diabetic women over 60 take aspirin daily if they have risk factors (high blood pressure, smoking, high cholesterol, family history of heart disease or albumin in the urine).
It is important to consult your doctor before beginning a daily aspirin regimen to make sure you meet the criteria. Taking aspirin daily without meeting criteria could put you at a higher risk for major bleeding. Also, if you have high blood pressure, it is important that you bring your blood pressure under control before starting daily aspirin. Starting daily aspirin if your blood pressure is too high can greatly increase your risk of hemorrhagic stroke. If you start to take daily aspirin, stick with the recommended 81mg daily. There is no evidence that taking more works any better and it may increase your risk for bleeding. Aspirin can be an effective tool for preventing heart attack and stroke if used correctly.
Author: Christi Larson, Pharm. D.
