In recent years, there have been a lot of stories in the news suggesting that daily aspirin therapy may be harmful.  

Some of the headlines on major news sites include “Daily aspirin may be harmful for healthy older adults, large study finds,” “Low-dose aspirin linked to bleeding in the skull, new report says,” and “Millions should stop taking aspirin for heart health, study says.” 

Reports like these have led to a lot of confusion among patients about who should, and should not, be taking a daily aspirin. I would like to help clarify what the guidelines and data suggest regarding the use of daily aspirin therapy to prevent cardiovascular events.

A history of prior heart events

Among patients with a history of prior cardiovascular events, such as heart attack or stroke, there is a large body of medical evidence supporting aspirin’s effectiveness at reducing the risk of recurrent events, called “secondary prevention”.  For many years, most of the medical community reasoned that aspirin use should also prevent a first heart attack or stroke and many guidelines have recommended aspirin for what is called “primary prevention”.  

Despite this belief, there was very little data to actually support it.  Very old clinical trials suggested a very small potential benefit of aspirin in primary prevention. Over the past 10 years or so, a few smaller clinical trials failed to find benefit of aspirin in primary prevention.  And within the past year, three large studies were published and well-publicized that again failed to find a benefit for aspirin in primary prevention.  

In response to a trial in March 2019, the American Heart Association (AHA) changed their guidelines regarding aspirin for primary prevention.  It is important to know that there have been no changes in recommendations for secondary prevention.

Not for primary prevention

Notably, the AHA now explicitly recommends against using aspirin for primary prevention in patients over 70 years old due to evidence of potential harm without benefit in recent studies.  For patients between 40 and 69 years old, the AHA weakened the recommendation for aspirin in primary prevention to the lowest grade possible stating it “might be considered” in certain circumstances.

Unfortunately, many patients with established cardiovascular disease stopped aspirin based on news reports that sounded like aspirin is harmful. One of my own patients came in recently with a recurrent heart attack after stopping aspirin because of news reports of harm, not realizing the new recommendations only apply to primary prevention, not secondary prevention for patients with prior cardiovascular events.  

The recommendations

  • If you have a history of a cardiovascular events, you generally should be taking a daily aspirin, but if you are not taking aspirin do not start without a discussion with your doctor. There may be a reason why you are not on aspirin. 
  • If you do not have known cardiovascular disease and are not taking a daily aspirin, then you should not start aspirin therapy without a risk/benefit discussion with your doctor.  Recent data suggest that most patients will not benefit from daily aspirin, however, for some patients there may be benefits.
  • If you are between the ages of 40 and 69 and already taking aspirin for primary prevention, it is reasonable to discuss the risk/benefit of aspirin at your next doctor visit. 
  • If you are over 70 and already taking aspirin for primary prevention, you should ask your doctor whether to stop taking it.  Again, everyone is a unique individual and you should not stop or start any medication without guidance from your doctor.  

Recent trials of aspirin in primary prevention, and clinical trials in general, help physicians know whether a particular treatment may be beneficial when used routinely.  But for any individual patient, there may be modifying factors that need to be considered before implementing specific guideline recommendations.  That is why every medication should be taken under individualized medical guidance and not based on reports in the news.

For more information on heart health and to learn more about the Lifespan Cardiovascular Institute, visit our website.

George T. Charlton, MD, FACC

Dr. George T Charlton is a cardiologist with the Lifespan Cardiovascular Institute at Newport Hospital.