Low Dose Aspirin: Who needs it?

Christopher Fuchs Pharm.D. Candidate 2015 St. Louis College of Pharmacy

Christopher Fuchs
Pharm.D. Candidate 2015
St. Louis College of Pharmacy

This is a common scenario: A patient comes into the pharmacy wondering if he or she should start taking a daily aspirin. They have a friend or family member that takes it and suggested they should too. How should a pharmacist respond to this question? One simple and correct answer would be to have the patient talk about aspirin use with his or her physician. However, as pharmacists we are able to tell patients and physicians the most up-to-date recommendations and backgrounds on medications.

Currently low dose 81 mg aspirin is recommended as both primary and secondary prevention of cardiovascular disease. Primary prevention is when aspirin is used to prevent a cardiovascular event in a patient with no history of cardiovascular events. For secondary prevention is when aspirin is used to prevent a subsequent cardiovascular event in a patient who has already had one. For secondary prevention, the 2013 ACCF/AHA Guideline recommends low doses of aspirin for the Management of ST-Elevation Myocardial Infarction in post-STEMI patients.2 It is also recommended for secondary prevention of stroke by Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.3

Aspirin for secondary prevention is widely recommended, but the use of aspirin for primary cardiovascular prevention is less clear. The U.S. Preventive Services Task Force recommends low dose aspirin use in two scenarios based on age and 10-year myocardial infarctions (MI) or 10-year stroke risk1:

  • Men age 45 to 79-years-old for prevention of myocardial infarctions (MI)
  • Women Age 55 to 79-years-old for prevention of ischemic stroke
Aspirin’s benefit outweighs risk in patients:
Age 10-year MI Risk
(men)
Age 10-year Stroke Risk
(women)
45-59 ≥ 4 % 55-59 ≥ 3 %
60-69 ≥ 9 % 60-69 ≥ 8 %
70-79 ≥ 12 % 70-79 ≥ 11 %

 

The Task Force’s recommendations were published in 2009.

There are many other modifiable factors that play a role in cardiovascular disease (CVD). Blood pressure, smoking status, and cholesterol level are all major factors in determining the risk of having a cardiovascular event. Once a patient has his or her hypertension and/or hyperlipidemia controlled, the benefit versus risk for aspirin might have changed. It is important for clinicians to reassess aspirin use on a regular basis. It is an important part of patient care to make sure the patient’s therapies are appropriate and indicated. If the risk of a medication outweighs the benefit, it should not be recommended.

New trials have recently come out that show the risk of adverse effects is greater than the risk reduction for stroke and/or MI. The recent Japanese Primary Prevention Project, which looked at the use of aspirin at 100 mg versus placebo in 14,464 patients, did not find a significant difference between aspirin and placebo in the combined primary endpoint of cardiovascular death, nonfatal stroke, and/or nonfatal MI (p=0.54).4 Aspirin patients were twice as likely to have a duodenal ulcer and three times as likely to have a gastrointestinal (GI) bleed.4

The U.S. Food and Drug Administration (FDA) released a statement in May 2014, recommending against the use of aspirin for primary prevention. The Center for Disease Control and Prevention’s (CDC) Million Hearts Campaign agrees with the FDA’s statement. The FDA states:

“There are serious risks associated with the use of aspirin, including increased risk of bleeding in the stomach and brain, in situations where the benefit of aspirin for primary prevention has not been established.”

As pharmacists we are viewed as the medications experts by both patients and physicians. It is our duty to explain the risks and benefits of medications to our patients and educate them on the common adverse effects. An educated patient is frequently one that can actively participate in their own care and a healthier patient. When communicating with physicians, we should be using the latest guidelines and/or recommendations about therapies. Currently, the use of aspirin for primary cardiovascular disease prophylaxis is controversial and not universally agreed upon. Hopefully, in coming months the U.S. Preventative Services Task Force will update its recommendations to address the FDA’s newest statement.

Christopher Fuchs
Pharm.D. Candidate 2015
St. Louis College of Pharmacy

 

References:

  1. Aspirin for the Prevention of Cardiovascular Disease: Preventive Medication. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf/uspsasmi.htm. Published March 2009. Accessed November 25, 2014.
  2. O’Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013;61(4):e78-e140. doi:10.1016/j.jacc.2012.11.019.
  3. Lansberg MG, O’Donnell MJ, Khatri P, et al. Antithrombotic and thrombolytic therapy for ischemic stroke. Chest.2012;141(2_suppl):e601S-e636S. doi:10.1378/chest.11-2302.
  4. Ikeda Y, Shimada K, Teramoto T, et al. Low-Dose Aspirin for Primary Prevention of Cardiovascular Events in Japanese Patients 60 Years or Older With Atherosclerotic Risk Factors: A Randomized Clinical Trial. JAMA. 2014;

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