USPSTF Releases Updated Recommendations on Aspirin Use for Primary Prevention of Cardiovascular Disease

After releasing draft recommendations for public comment in the fall of 2021, the US Preventive Services Task Force (USPSTF) has released a new recommendations statement outlining the group’s stance on use of aspirin to prevent cardiovascular disease.

After a systematic review and microsimulation, statement authors concluded, with moderate certainty, aspirin use for primary prevention of cardiovascular disease in adults aged 40-59 years who have a 10% or greater 10-year cardiovascular disease risk provided a small net benefit, but also concluded, with moderate certainty, initiating aspirin therapy for the primary prevention in adults 60 years or older provided no net benefit.

“Based on current evidence, the Task Force recommends against people 60 and older starting to take aspirin to prevent a first heart attack or stroke,” said Task Force vice chair Michael Barry, MD, in a statement from the USPSTF. “Because the chance of internal bleeding increases with age, the potential harms of aspirin use cancel out the benefits in this age group.”

As more and more contemporary data emerge related to the realities surrounding use of aspirin for prevention of cardiovascular disease, the US Preventive Services Task Force recommendations provide further guidance for clinicians with patients who are already taking aspirin or who may have questions related to aspirin use for cardiovascular prevention. As part of the recommendation writing process, investigators conducted a systematic review of literature assessing the effectiveness of aspirin for reducing risk of cardiovascular events, cardiovascular mortality, and all-cause mortality in patients without a history of cardiovascular disease. Of note, recommendation authors also conducted a review of the aspirin use on colorectal cancer incidence and mortality in primary cardiovascular disease prevention populations, as well as bleeding risk associated with aspirin use.

The systematic review assessed English-language randomized clinical trials of low-dose aspirin, which was defined as 100 mg/d or less, compared against placebo therapy or no intervention in primary prevention populations published through January 2021. Through a search of MEDLINE, PubMed, Embase, and Cochrane Central Register of Controlled Trials, investigators identified 11 randomized clinical trials and 1 pilot study for inclusion in their review. From the randomized trials, investigators obtained data related to 134,470 individual participants and, from the pilot trial, investigators obtained data related to 400 additional individuals.

Analysis of these trials indicated low-dose aspirin use was associated with a significant decrease in major cardiovascular events (OR, 0.90 [95% CI, 0.85 to 0.95]; 11 RCTs [n = 134,470]; I2=0%; range in absolute effects, −2.5% to 0.1%), but aspirin use was not significantly associated with reductions in cardiovascular disease mortality or all-cause mortality. Analysis of the safety of aspirin use indicated use of low-dose aspirin was associated with significant increases in total major bleeding (OR, 1.44 [95% CI, 1.32 to 1.57]; 10 RCTs [n = 133,194]; I2=4.7%; range in absolute effects, 0.1% to 1.0%) and site-specific bleeding.

In the 2016 recommendation statement on aspirin use to prevent cardiovascular disease and colorectal cancer, the USPSTF recommended low-dose aspirin for primary prevention in adults aged 50-59 years who have a 10% or greater 10-year cardiovascular disease risk, who are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years. This was given a grade B recommendation. The writing committee concluded there was insufficient evidence to provide a recommendation on use in a population younger than 50 years.

In their 2022 update, authors provide a grade C recommendation for use of low-dose aspirin in adults aged 40-59 years with a 10% or greater 10-year cardiovascular disease risk. Authors noted the decision to initiate therapy in the aforementioned patient population should be an individual one. Also in their 2022 recommendations, the USPSTF recommended against initiating low-dose aspirin use for the primary prevention of CVD in adults 60 years or older. This was given a grade D recommendation.

In an editorial, Donald Lloyd-Jones, MD, ScM, president of the American Heart Association, reviewed some of the landmark studies that have helped to shape and reshape the role of aspirin in cardiovascular prevention.

“The draft and final versions of the new USPSTF recommendations for primary preventions were and are correct and appropriately reflect the progress of the evidence base, although they differ somewhat in substance and scope from the ACC/AHA guidelines,” Lloyd-Jones wrote. “The lesson for all guideline-producing organizations is the importance of ensuring clear and broad-based communication strategies in the introduction of updated recommendations, and whom they affect and do not affect, based on new and improved evidence. Patients depend on us to do that.”

These articles, “Aspirin Use to Prevent Cardiovascular Disease US Preventive Services Task Force Recommendation Statement,” and “Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer Updated Evidence Report and Systematic Review for the US Preventive Services Task Force,”, were published in JAMA.