Are Your Patients Using Low-Dose Aspirin for Primary Prevention of Heart Disease?

It’s no secret that more than a few patients at low risk for cardiovascular disease take daily low-dose aspirin, but how many of your patients would you estimate are doing so?

If you guessed anything less than one-quarter, you’re likely being overoptimistic, according to an analysis of the 2017 National Health Interview Survey published in the Annals of Internal Medicine (2019 July 23 [Epub ahead of print]).

The survey of 14,328 U.S. adults age 40 or older found that 23.4% reported taking daily low-dose aspirin “to prevent or control heart disease,” and 22.8% of those adults were doing so without a physician’s recommendation. Aspirin use increased with age, with 45% of adults over age 70 without cardiovascular disease reporting that they take daily aspirin.

A moving target

Since the use of aspirin for primary prevention has been a moving target, some patients may be unaware that recommendations have changed. Until this year, the American Heart Association and American College of Cardiology (AHA/ACC) only recommended against low-dose aspirin use in patients with elevated bleeding risk.

But after three randomized, controlled primary prevention trials published in 2018 found little benefit and consistent bleeding risks with aspirin, the AHA/ACC updated their guidelines in March 2019.

The new guidelines indicate that aspirin may be considered in selected individuals ages 40 to 70 who are at higher cardiovascular risk and do not have increased bleeding risk. The guidelines also state explicitly that aspirin should not be routinely administered for primary prevention of cardiovascular disease in adults older than 70 or in adults of any age at increased bleeding risk.

But many patients apparently have not gotten the message or have chosen to disregard it. Although inappropriate aspirin use may be lower today than in 2017 as a result of the 2019 AHA/ACC guidelines update, it’s unlikely that nearly 30 million U.S. adults have stopped self-prescribing aspirin.

A Cleveland Clinic perspective

In light of these findings, Consult QD asked Leslie Cho, MD, Section Head of Preventive Cardiology and Rehabilitation at Cleveland Clinic, how physicians might discourage patients from self-prescribing low-dose aspirin.

Q: Since the problem appears to be more widespread than suspected, what can physicians do to deter inappropriate aspirin use?

A: It’s important to tell patients that aspirin is not benign, even at low doses. It is not a vitamin. If patients have no risk factors for cardiovascular disease, or their risk factors are well controlled, aspirin is not likely to be helpful.

We should remind patients that as they age, their bleeding risk will outweigh any benefits if they have not had a heart attack. This is why the AHA/ACC guidelines no longer recommend routine aspirin use in patients over age 70.

Q: Which patients are among the “selected” that the AHA/ACC says might benefit from aspirin for primary prevention?

A: It may not be primary cardiovascular prevention, but it’s important not to forget that there may be noncardiac reasons for recommending aspirin. For instance, some patients without cardiovascular disease may need to take aspirin, including those at heightened risk for colorectal cancer.

In Cleveland Clinic’s Preventive Cardiology Program, we use a proprietary algorithm to help us determine when to prescribe aspirin. In general, we like the idea of using aspirin when a patient has a strong family history of cardiovascular disease, a high coronary calcium score or elevated hs-CRP or lipoprotein(a), and also if the patient is a current smoker or has risk factors that are not well controlled.

We also may prescribe aspirin for patients who have had type 2 diabetes for more than 10 years or type 1 diabetes for more than 20 years, as well as for diabetic patients with albuminuria, retinopathy, neuropathy or peripheral artery disease.

At the same time, we assess bleeding risk from factors such as low platelet count, history of bleeding, peptic ulcer disease, fall risk, alcohol use, coagulopathy, chronic kidney disease or concomitant use of NSAIDs, steroids or anticoagulants.

It’s not a simple issue, but I would recommend the figure in a recent “Viewpoint” article published by Chiang and colleagues in JAMA (2019;322:301-302). That figure outlines a practical stepwise approach to considering aspirin in primary prevention that many physicians may find helpful.

Q: What about aspirin for secondary prevention?

A: The value of aspirin for secondary prevention of cardiovascular disease is not controversial. We always recommend aspirin for secondary prevention. Even if patients have aspirin allergy, we will desensitize them to aspirin so that they can take it.

Unfortunately, in this population we too often see the opposite issue: Some patients discontinue aspirin without our permission, which is an unsafe practice that can lead to another heart attack. But that is a detailed topic that merits a separate discussion.