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5MinuteConsult Journal Club

Aspirin Not Really for Primary Prevention


New Recommendations:

Old Recommendations:

Study Summary

AHA/ACC and USPSTF have recently updated their positions on using Aspirin for primary prevention of cardiovascular disease. While Aspirin for primary CVD prevention lowers MI risk, its harmful effects make using Aspirin more dangerous than beneficial.

The following case study will provide methods to answer patient questions for those currently taking Aspirin, or for those who are wondering about starting to take it.

Case Study

Peng is a 58-year-old male with GERD and hypertension who does not exercise; his ASCVD risk score is 7.7%. Years ago, you recommended he start 81 mg of Aspirin a day to help prevent adverse cardiovascular outcomes. He heard on the news recently that maybe taking the Aspirin is no longer recommended and he wants to know if he should keep taking it.

What led you to recommend that Peng start 81 mg of Aspirin in the past?

In 2016 USPSTF gave a B grade recommending Aspirin use to prevent CVD and colorectal cancer (CRC) for those aged 50 to 59 years who have a 10% or greater 10-year CVD risk, who are not at increased risk for bleeding, and have a life expectancy of at least 10 years for at least 10 years.

For those 60-69, they gave a C recommendation, recommending shared decision making for those who have a 10% or greater 10-year CVD risk and for those under 50 or over 70, they gave an I (insufficient evidence) regarding Aspirin for primary prevention.

This, along with the AHA’s lipid guideline, led us to aggressively use the ASCVD risk calculator to determine if someone should take Aspirin for primary prevention.

In 2019, based upon the ASCEND, ASPREE and ARRIVE trial, the ACC/AHA noted that Aspirin for primary prevention had “conflicted” evidence about benefit, but clear risks of “Serious Adverse GI Bleeds” offsetting any benefit. They concluded “Low-dose Aspirin MAY be considered for primary prevention of ASCVD among adults aged 40-70 years who possess higher ASCVD risk but remain at low probability for bleeding events,” and do not recommend it for those over the age of 70.

So, what has changed?

In October 2021, the USPSTF issued a draft recommendation: For those aged 40 to 59 who are at higher risk for cardiovascular disease (have a 10-year ASCVD RISK SCORE greater than or equal to 10), have a shared decision-making discussion about Aspirin’s risks and benefits.

They recommend against people ages 60 or older starting to take Aspirin for heart disease and stroke prevention, given the bleeding risks.

For all: Aspirin should not be recommended for primary prevention among adults at any age who are at increased bleeding risk.

Shared decision making; what are the risks and benefits of Aspirin?

When used in those aged 40-59 the NNT to prevent one Major Adverse CV event (including MI) was 265. But, there was no mortality benefit AND the NNH to cause a Major GI Bleed was 210; meaning the risk of the GI Bleed were higher than the potential for benefit.

In Peng’s case, with his history of GERD, even if his risk was over 10, I would suggest he stop it.

What remains unclear is what to do with patients who have diabetes. Their ASCVD score will be likely be high, but the ASCEND trial, which showed a benefit to 100 mg of Aspirin, also had that benefit negated by the even higher Major GI bleed risk.

So, no Aspirin for Peng. What can he and other patients do to provide primary prevention of ASCVD?

- Walking more than 8,000 steps per day, Short HIIT, or 20 minutes of moderate intensity exercise

- Getting weight out of the obese BMI range (and lowering DM & NAFLD risk)

- A diet high in non-starchy vegetables and fresh fruits, fatty fish twice a week, consuming vegetable oils

- Not smoking

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Contributed by Frank J. Domino, MD, October 20, 2021