Last month, media headlines claimed that aspirin had more risk than benefit for older adults, and a few media articles went so far as to suggest that people throw away their aspirin. The truth is that the recently published studies didn't make this recommendation. It does bring up an important point since everyone should know who might still benefit from aspirin therapy, and who is likely to be harmed by it. Aspirin is derived from the bark of willow trees. It has been used for centuries for pain, fever, and inflammation. Baby aspirin has also been used for decades to reduce the risk of heart attacks and stroke. Yet, aspirin has been shown to carry both benefits and risk for people taking it. The established benefit has been reducing the risk for a heart attack or stroke by blocking clot formation in arteries. The known risk of taking aspirin has been from spontaneous bleeding, with sometimes fatal or disabling consequences. For the past 20 years, standard medical recommendations have been that people at high risk for a heart attack or stroke have had more benefit from taking a baby aspirin daily (84-100 mg per day). In contrast, people at low risk for a heart attack or stroke were more likely to be harmed by bleeding and should avoid using it. Last month, The New England Journal of Medicine (NEJM), published three research articles with findings from the ASPREE trial. These publications have achieved worldwide media attention, and due to this broadcasting sensation, several of my patients have called my office confused and seeking advice. After reading the articles in detail, here is the information that I shared with them. What was the purpose of the ASPREE trial? The Aspirin in Reducing Events in the Elderly (ASPREE) trial was a double-blind, randomized, placebo-controlled trial (RCT) that investigated whether the potential primary prevention benefits of low-dose aspirin outweighed the risks in healthy older adults. Participants were randomized to two groups; one group received daily aspirin (100 mg per day) and the other received daily matching placebo that contained no active ingredients. The study was designed to answer one primary research question: Would daily use of aspirin for 5 years prolong disability-free life in healthy older adults? The secondary research questions from this study aimed to see if daily use of aspirin for 5 years would impact death rates, heart attacks and strokes, cardiovascular procedures, cancer, dementia, memory loss, depression, physical disability, and clinically significant bleeding in healthy older adults. The main hypothesis of the study was that daily low-dose aspirin would extend disability-free and dementia-free life in these healthy elder adults. To understand the results of this trial, it is important to know who was excluded and who was included in this trial. The subjects in the ASPREE trial were healthier than the average general public of similar ages. From 2010 through 2014, they enrolled community-dwelling persons in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or disability. Participants were randomly assigned to receive 100 mg of enteric-coated aspirin or placebo. The following people were excluded:
- Anyone with significant chronic disease that would likely limit their survival to <5 years, excluding people with lung disease, kidney disease, or a history of cancer.
- Anyone with any history of cardiovascular disease
- Anyone with a major physical disability, including memory loss
What did the ASPREE trial find? Of the 19,114 persons who were enrolled, 9525 were assigned to receive aspirin and 9589 to receive placebo. A total of 1052 deaths occurred during a median of 4.7 years of follow-up. The risk of death from any cause was 12.7 events per 1000 person-years in the aspirin group and 11.1 events per 1000 person-years in the placebo group; this means taking aspirin in this subject population increased the risk of death by 1.6%. A surprise finding was that cancer was the major contributor to the higher mortality in the aspirin group, accounting for 1.6 excess deaths per 1000 person-years. Cancer-related deaths occurred in 3.1% of the participants in the aspirin group and 2.3% in the placebo group, a 0.8% increase. The bottom line is that for healthy adults over the age of 65-70, taking a baby aspirin did not prevent death rates. And in these healthy, older adults, they had a higher risk for a major bleeding event and death from any cause. There was a slight decrease in heart attacks and strokes, but this was offset by a greater risk for bleeding and/or cancer, in particular, colon cancer. The findings from the ASPREE trial support prior recommendations that healthy adults experience more harm than benefit from taking a baby aspirin daily. Keep in mind, the ASPREE study did not evaluate the benefits of aspirin for adults that are at high risk for a cardiovascular event (heart attack or stroke), who have already had a heart attack or stroke, or who have a history of colon polyps or colon cancer. For patients with a past history of a heart attack or stroke, or those who are high risk for a cardiovascular event and have excess arterial plaque (such as from a carotid IMT study), then I still recommend that they take a baby aspirin daily. Also, for people with a history of colon polyps and colon cancer, prior studies have shown that taking low-dose aspirin reduces the risk for recurrent colorectal adenomas compared to placebo and that they are less likely to suffer from metastatic colon cancer as well. Summary If you are healthy there is more harm than benefit from taking low-dose aspirin daily long term. If you are high risk for a heart attack or stroke, or have had prior colon polyps or colon cancer, then you might benefit from daily low-dose aspirin therapy; therefore, talk to your doctor to clarify if you would have greater benefit than risk from taking a baby aspirin daily. I wish you the best of health! Steven Masley, MD, FAHA, FACN, FAAFP, CNS References
- McNeil JJ, et al. Effect of aspirin on disability-free survival in the healthy elderly. NEJM. 2018. DOI: 10.1056/NEJMoa1800722.
- McNeil JJ, et al. Effect of aspirin on cardiovascular events and bleeding in the healthy elderly. NEJM. 2018. DOI: 10.1056/NEJMoa1805819.
- McNeil JJ, et al. Effect of aspirin on all-cause mortality in the healthy elderly. NEJM. 2018. DOI: 10.1056/NEJMoa1803955.