Preventing heart attacks: Is aspirin a safe choice?

The Bottom Line

  • Many health care providers recommend aspirin to prevent heart attacks, but whether it should be given to healthy adults with no history of heart disease has been hotly debated.
  • While aspirin may lower the risk of heart attack in those without heart disease by a small amount, it does not reduce the risk of death or stroke.
  • Aspirin may increase the risk of major bleeding, including bleeding in the brain or skull.
  • Thinking of taking aspirin for your heart health or already using it? Speak with your health care provider about the potential risks and benefits. 

You’ve probably heard that taking a daily dose of aspirin can lower your risk of heart attack (1-7). With about 20% of older adults taking aspirin as a preventative strategy (8;9), there is no question that it is commonly prescribed. But do its benefits outweigh its risks? This has been a matter of controversy (8), especially when it comes to healthy adults.

Why prescribe aspirin to prevent heart attacks? Aspirin (or acetylsalicylic acid) prevents blood clots (1). Blood clotting occurs when cells called platelets clump together and seal up a bleeding wound. Because blood clots that block the flow of blood to the heart can lead to a heart attack, stopping this process lowers your risk of a heart attack.

What’s the catch? Because taking aspirin can make it difficult to form blood clots, it also increases the risk of internal bleeding (1;2;8;10).

So, is aspirin a safe choice for heart attack prevention when both the benefits and risks are considered together? This is a matter of hot debate. Some guidelines recommend it for people at a higher risk for heart attack (8;11;12), whereas other guidelines don’t recommend it at all (8;13). And while there is research that supports its use in people with a history of heart attack or stroke, (8;11;12), evidence supporting its use in healthy adults is less clear (8;14;15).

Given all of the conflicting evidence and guidelines, a recent systematic review took a closer look at the benefits and risks of aspirin use in adults with no history of heart disease—including outcomes such as stroke, heart attacks, blood clots in the legs, and so on (8).

So, just what did this review find?

What the research tells us

The results showed that taking aspirin didn’t lower the risk of death from any cause in adults without a history of heart disease, compared to those taking placebo or nothing at all. These findings held true even when considering people’s risk of major cardiovascular events, if they had diabetes or not, and the dose of aspirin they were taking (in most cases, people were taking 75 mg to 100 mg per day). What’s more, aspirin didn’t reduce the risk of death from heart disease-related complications or the risk of stroke.

With respect to having a heart attack, the results varied across studies; but even in the best case scenario heart attacks were slightly less common in adults taking aspirin—about 3 fewer people out of 1000 having a heart attack. That being said, when older studies were removed from the analysis and only newer studies considered, no reduction in heart attacks among those taking aspirin was seen. In terms of negative side effects, those taking aspirin were more likely to experience major bleeding—including bleeding inside the brain or skull.

So, in people with no history of heart disease, aspirin may do more harm than good. But, before tossing your bottle of aspirin from your medicine cabinet, make sure to talk to your health care provider about its potential risks and benefits for you as an individual (8).

Folks should also keep in mind that the findings discussed here are for adults who do not have a history of heart disease, and so do not apply to those with a history of heart disease or stroke.

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Author Details


  1. Mayo Clinic. Daily aspirin therapy: Understand the benefits and risks. [Internet] 2019. [cited June 2019].
  2. McNeil JJ, Wolfe R, Woods RL, et al. Effect of aspirin on cardiovascular events and bleeding in the healthy elderly. N Engl J Med. 2018; 379:1509-1518. doi: 10.1056/NEJMoa1805819. 
  3. Hennekens CH, Dyken ML, Fuster V. Aspirin as a therapeutic agent in cardiovascular disease: A statement for healthcare professionals from the American Heart Association. Circulation. 1997; 96(8):2751-27533. 
  4. Ajani UA, Ford ES, Greenland KJ, et al. Aspirin use among U.S. adults: Behavioral risk factor surveillance system. Am J Prev Med. 2006; 30(1):74-77. 
  5. Ittaman SV, VanWormer JJ, Rezkalla SH. The role of aspirin in the prevention of cardiovascular disease. Clin Med Res. 2014; 12(3-4): 147-154. doi: 10.3121/cmr.2013.1197.
  6. Duffy D, Kelly E, Trang A, et al. Aspirin for cardioprotection and strategies to improve patient adherence. Postgrad Med. 2014; 126(1):18-28. doi: 10.3810/pgm.2014.01.2721.
  7. Gu Q, Dillon CF, Eberhardt MS, et al. Preventive aspirin and other antiplatelet medication use among U.S. adults aged ≥40 years: Data from the National Health and Nutrition Examination Survey, 2011–2012. Public Health Rep. 2015; 130(6): 643-654. 
  8. Mahmoud AN, Gad MM, Elgendy AY, et al. In people who do not have cardiovascular disease, aspirin does not reduce risk for death but does increase major bleeding. Eur Heart J. 2019; 60:607-617. doi: 10.1093/eurheartj/ehy813. 
  9. Stuntz M, Bernstein B. Recent trends in the prevalence of low-dose aspirin use for primary and secondary prevention of cardiovascular disease in the United States, 2012-2015. Prev Med Rep. 2017; 5:183-186. doi: 10.1016/j.pmedr.2016.12.023.
  10. Raju N, Sobieraj-Teague M, Hirsh J, et al. Effect of aspirin on mortality in the primary prevention of cardiovascular disease. Am J Med. 2011; 124(7):621-629. doi: 10.1016/j.amjmed.2011.01.018.
  11. Bibbins-Domingo K; U.S. Preventive Services Task Force. Aspirin use for the primary prevention of cardiovascular disease and colorectal cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2016; 164(12): 836-845. doi: 10.7326/M16-0577.
  12. Fox CS, Golden SH, Anderson C, et al. Update on prevention of cardiovascular disease in adults with type 2 diabetes mellitus in light of recent evidence: A scientific statement from the American Heart Association and the American Diabetes Association. Circulation. 2015; 132(8):691-718. doi: 10.1161/CIR.0000000000000230.
  13. Piepoli MF, Hoes AW, Agewall S, et al. 2016 European Guidelines on cardiovascular disease prevention in clinical practice: The Sixth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of 10 societies and by invited experts), Developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR). Eur Heart J. 2016; 37(29): 2315-2381. doi: 10.1093/eurheartj/ehw106.
  14. Cleland JG. Is aspirin “the weakest link” in cardiovascular prophylaxis? The surprising lack of evidence supporting the use of aspirin for cardiovascular disease. Prog Cardiovasc Dis. 2002; 44(4):275-292. 
  15. Cleland JGF. Physicians Addicted to Prescribing Aspirin-a Disorder of Cardiologists (PAPA-DOC) syndrome: The headache of nonevidence-based medicine for ischemic heart disease? JACC Heart Fail. 2018; 6(2):168-171. doi: 10.1016/j.jchf.2017.11.014.

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