Is aspirin (acetylsalicylic acid) indicated for primary prevention of cardiovascular events?

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Last updated: April 10, 2025View editorial policy

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From the Guidelines

Aspirin is generally not recommended for primary prevention of cardiovascular disease for most individuals, especially those over 70 years old, due to the increased risk of bleeding that outweighs the potential benefits. The decision to use aspirin for primary prevention should be individualized based on a person's specific cardiovascular risk factors and bleeding risk, as suggested by the most recent study 1. For adults aged 40-59 years with a 10% or greater 10-year cardiovascular risk, aspirin might be considered after discussion with a healthcare provider. However, for adults 60 years or older, aspirin should not be initiated for primary prevention due to increased bleeding risks.

When considering aspirin for primary prevention, it is essential to weigh the potential benefits against the risks, including the increased risk of major bleeding, as seen in the ASCEND trial 1. The typical dose of aspirin for primary prevention is low-dose aspirin (81-100 mg daily). Aspirin works by inhibiting platelet aggregation, thereby reducing clot formation, but this same mechanism increases bleeding risk. Before starting aspirin, patients should have their cardiovascular risk formally assessed using a risk calculator and discuss both potential benefits and harms with their healthcare provider.

Key considerations for aspirin use in primary prevention include:

  • Cardiovascular risk factors, such as family history of premature ASCVD, hypertension, dyslipidemia, smoking, or chronic kidney disease/albuminuria
  • Bleeding risk, including older age, anemia, or renal disease
  • Individualized assessment of benefits and risks using a risk calculator
  • Shared decision-making with a healthcare provider to determine the best course of action. Individuals already taking aspirin should not stop without consulting their doctor, especially those with established cardiovascular disease, as aspirin remains beneficial for secondary prevention after heart attack or stroke, as supported by the Antithrombotic Trialists’ Collaboration 1.

From the Research

Aspirin Use for Primary Prevention

The use of aspirin for primary prevention of cardiovascular disease is a complex issue, with both benefits and risks to consider.

  • Aspirin use has been associated with a reduced risk of cardiovascular events, including myocardial infarction and stroke 2.
  • However, aspirin use also increases the risk of major bleeding events, including gastrointestinal bleeding and hemorrhagic stroke 3, 2.
  • The balance between the potential benefits and risks of aspirin use for primary prevention is critical, and individualized assessment of aspirin's effects on bleeding risks and expected benefits is necessary 3.

Eligibility for Aspirin Use

The eligibility for aspirin use for primary prevention of cardiovascular disease is determined by various factors, including age, cardiovascular risk, and bleeding risk.

  • According to the 2022 US Preventive Services Task Force guidelines, adults aged 40-59 years with a 10-year cardiovascular risk of 10% or higher and without increased bleeding risk may be eligible for aspirin use for primary prevention 4.
  • Approximately 7.2 million US adults aged 40-59 years (10% of the population) are eligible for consideration of primary prevention aspirin, with men, older adults, and Black individuals having higher proportions meeting eligibility criteria 4.

Special Considerations

Certain populations may have different considerations for aspirin use for primary prevention.

  • Individuals with elevated lipoprotein(a) may benefit from aspirin therapy for primary prevention of atherosclerotic cardiovascular disease, with approximately 50% reduction in risk for coronary heart disease events and ASCVD mortality with aspirin use among individuals with Lp(a) > 50 mg/dL 5.
  • The use of enteric-coated aspirin vs noncoated aspirin should be reassessed, and a bleeding risk calculator may be useful to support clinicians' assessment of risk vs benefit 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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