Rethinking daily aspirin for primary prevention
An updated meta-analysis of newer RCTs seems to settle the matter as to whether to use aspirin in individuals with no known history of atherosclerotic CVD.
PRACTICE CHANGER
Do not routinely use aspirin for primary prevention of cardiovascular disease (CVD). There is no identifiable mortality benefit for those without established CVD—regardless of risk factors. And aspirin therapy increases the risk of major bleeding.
STRENGTH OF RECOMMENDATION
A: Based on a meta-analysis of 11 randomized trials involving 157,248 patients who received aspirin for primary prevention.1
Mahmoud AN, Gad MM, Elgendy AY, et al. Efficacy and safety of aspirin for primary prevention of cardiovascular events: a meta-analysis and trial sequential analysis of randomized controlled trials. Eur Heart J. 2019;40:607-617.
The USPSTF guidelines in 2016 recommended prescribing daily aspirin for adults ages 50 to 59 who have a > 10% 10-year CVD risk and discussing with adults ages 60 to 69 the risks and benefits of daily aspirin.2
The 2019 American College of Cardiology/American Heart Association guidelines state that aspirin should no longer be used routinely for primary prevention, given the lack of net benefit. Patients ages 40 to 70 who are not at increased risk of bleeding with a higher risk of CVD may be considered for daily low-dose aspirin. The guidelines also state that adults > 70 years or those with increased risk of bleeding should not be started on a daily aspirin.4
CAVEATS
Jury is still out regarding very high-risk patients
While the meta-analysis by Mahmoud and colleagues makes a good case for discontinuing aspirin for primary prevention in most patients, the data do not examine in detail whether there is a benefit in patients with very high risk (> 20%) for atherosclerotic CVD. More studies are needed before making recommendations for that specific subgroup.
CHALLENGES TO IMPLEMENTATION
Patients may not be eager to give up an accepted practice
Physicians have been recommending aspirin for primary prevention of CVD for decades and many patients, who purchase aspirin themselves, are vested in the notion that aspirin protects them. It will take time for this change in practice to be accepted. Some patients may continue taking aspirin despite recommendation to stop. Primary care physicians will need to educate patients and clearly explain the rationale for stopping daily aspirin.
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center for Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center for Research Resources or the National Institutes of Health.
