Cardiovascular disease (CVD) is the leading cause of mortality in the US, accounting for more than 1 in 4 deaths. Each year, an estimated 605 000 people in the US have a first myocardial infarction and an estimated 610 000 experience a first stroke.

To update its 2016 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a systematic review on the effectiveness of aspirin to reduce the risk of CVD events (myocardial infarction and stroke), cardiovascular mortality, and all-cause mortality in persons without a history of CVD. The systematic review also investigated the effect of aspirin use on colorectal cancer (CRC) incidence and mortality in primary CVD prevention populations, as well as the harms (particularly bleeding) associated with aspirin use. The USPSTF also commissioned a microsimulation modeling study to assess the net balance of benefits and harms from aspirin use for primary prevention of CVD and CRC, stratified by age, sex, and CVD risk level.

Adults 40 years or older without signs or symptoms of CVD or known CVD (including history of myocardial infarction or stroke) who are not at increased risk for bleeding (eg, no history of gastrointestinal ulcers, recent bleeding, other medical conditions, or use of medications that increase bleeding risk).

The USPSTF concludes with moderate certainty that aspirin use for the primary prevention of CVD events in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk has a small net benefit. The USPSTF concludes with moderate certainty that initiating aspirin use for the primary prevention of CVD events in adults 60 years or older has no net benefit.

The decision to initiate low-dose aspirin use for the primary prevention of CVD in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk should be an individual one. Evidence indicates that the net benefit of aspirin use in this group is small. Persons who are not at increased risk for bleeding and are willing to take low-dose aspirin daily are more likely to benefit. (C recommendation) The USPSTF recommends against initiating low-dose aspirin use for the primary prevention of CVD in adults 60 years or older. (D recommendation).