The role of aspirin in preventing atherosclerotic cardiovascular disease in patients with arteriosclerotic vascular disease (ASCVD) is well established.
Aspirin’s role in the primary prevention of ASCVD remains controversial.
Long-standing studies have had mixed results, but overall support the use of aspirin for primary prevention.
A number of recent large scale randomized controlled trials have cast doubt on the long term practice and have raised safety concerns.
ASPREE and ARRIVE primary prevention randomized controlled trials found no reduction in ASCVD events, but were associated with increased risk of major bleeding with randomization to aspirin.
Based on the above studies prevention guidelines were altered to state that aspirin should not be given to individuals over the age of 70 years or any aged individual with increased bleeding risk.
Recent guidelines suggest that aspirin be considered for primary ASCVD prevention in select adults age 40-70 years who are at an increased risk of ASCVD events and who are not at increased risk of bleeding.
Aspirins treatment effects do not increase as ASCVD risk increases.
There is no suggestion that the use of aspirin for a higher risk primary prevention patientzzz is beneficial (Nudy M).
It is concluded that aspirin has limited efficacy in the primary prevention of ASCVD and patients are at high risk for the first myocardial infarction or stroke, the effect of aspirin for ASCVD prevention is not greater compared with those at lower risk.
In primary prevention the relative reductions of a first myocardial infarction or a stroke are similar to those in the secondary prevention, but the absolute reductions are far lower.
The relative and absolute risk of adverse effects, primarily extra cranial bleeding is similar in both secondary and primary prevention.
In primary prevention the absolute benefits seem to outweigh absolute risks only when the ten year risk of a first event is greater than 10%.
US Preventive Services Task Force recommendation statement: The decision to initiate low-dose aspirin use for the primary prevention of cardiovascular disease in adults age 40 to 59 years who have a 10% or greater 10 year cardiovascular disease risk should be an individual one: the benefit of aspirin use in this group is small. Persons who are not an increased risk for bleeding and are willing to take low-dose aspirin daily are more likely to benefit.
The USPSTF recommends against initiating low-dose aspirin for the primary prevention of cardiovascular disease in adults 60 years or older.
Aspirin use as primary prevention significantly reduces ASCVD events but is unlikely to be clinically significant considering bleeding risk.
The reduction in ASCVD events is less than other treatment modalities aimed at primary prevention, including statins and blood pressure control.
In secondary prevention, evidence supports widespread prescription of daily aspirin during acute myocardial infarction, occlusive stroke, or unstable angina, as well as for a range of survivors with prior occlusivecardiovascular events to reduce subsequent high risks.
The risks for extra cranial bleeding are similar in aspirin use in primary and secondary prevention.
In primary prevention absolute benefits outweigh absolute risks only when the ten year risk of a first event is greater than 10%.
Age increases occlusion but also bleeding which complicates benefit to risk considerations for primary care management.
In patients using nonsteroidal anti-inflammatory drugs, or patient with upper G.I. symptoms all have high absolute bleeding risks with aspirin.