Recent guidelines have limited aspirin use in the primary prevention of cardiovascular disease. The American Heart Association (AHA) and American College of Cardiology (ACC) have restricted its use to patients under 70, while the United States Preventive Services Task Force has further narrowed it to those under 60. However, the risks of heart attacks and strokes increase with age, leaving healthcare providers uncertain about when to discontinue aspirin, whether it should be used for primary prevention, and which patients would benefit most.
Researchers from Florida Atlantic University’s Schmidt College of Medicine, along with collaborators from major aspirin trials in primary prevention, have published their perspectives in Clinical Trials to address concerns over current guidelines.
The researchers stress that randomised controlled trials should adhere to strict statistical principles in their design, conduct, analysis, and interpretation. Failure to do so can lead to misleading conclusions and poorly informed recommendations by guideline committees. They argue that both the AHA/ACC and the U.S. Preventive Services Task Force have been unduly influenced by the Aspirin in Reducing Events in the Elderly (ASPREE) trial, which failed to provide reliable evidence that aspirin offered no benefit to the age groups studied.
The researchers point out that the best evidence indicates that healthcare providers should make individualised clinical decisions on aspirin use based on a benefit-to-risk assessment, not age alone. It seems counterintuitive to stop aspirin for long-term users simply because they’ve reached a certain age milestone. Moreover, absence of evidence does not equate to evidence of no effect.
The authors emphasise that patients should discuss aspirin use with their primary care providers, who are best equipped to assess the individual benefits and risks for each patient. Healthcare providers can weigh the advantages of clot prevention against the potential risks of bleeding, making aspirin prescription a matter of individual judgment.
Any patient experiencing an acute heart attack should receive 325 milligrams of regular aspirin promptly, and continue daily thereafter to reduce their death rate and prevent further cardiovascular events. Likewise, patients who have survived previous heart attacks or strokes should continue long-term aspirin therapy, unless a contraindication exists.
The authors also highlight the growing burden of cardiovascular disease, underscoring the need for broader lifestyle changes—such as smoking cessation, weight loss, increased physical activity—and effective, affordable drug therapies for primary prevention. Aspirin is particularly appealing because of its low cost.
While patient preferences always matter in decision-making, they are especially important when the benefits and risks of aspirin are similar for different patients. For some, the prevention of a first heart attack or stroke may be a higher priority than the risk of a gastrointestinal bleed.
The authors note that the risk of a cerebral bleed, both with and without aspirin, is generally too low to be clinically significant for most patients. They argue that, in the U.S. and other developed countries, individualised clinical decisions on aspirin use for primary prevention could affect a significant number of patients. For example, metabolic syndrome, which includes factors like obesity, hypertension, high cholesterol, and insulin resistance, affects about 40% of Americans aged 40 and older and is becoming more common worldwide. Patients with metabolic syndrome face high risks of heart attacks and strokes, which could be similar to those of patients with prior events.
Current aspirin guidelines for primary prevention do not seem justified. Primary care providers, who have the most complete understanding of their patients’ overall health, should be the ones making these decisions.
Source: Florida Atlantic University
Image Credit: iStock
References:
Wittes J et al. (2025) Aspirin in primary prevention: Undue reliance on an uninformative trial led to misinformed clinical guidelines. Clinical Trials.
