Which scenario warrants initiating aspirin according to the guidelines?

• A. With ASCVD -> initiate ASA
• B. Image positive vascular disease -> consider initiating ASA
• C. DM with low ASCVD risk -> no ASA
• D. Age over 70 -> no ASA

Answer: (A)

Starting low-dose aspirin is clearly warranted when a patient has established ASCVD (such as a prior heart attack, stroke, or peripheral artery disease). In this scenario, the risk of recurrent coronary or cerebrovascular events is high, and the antiplatelet effect of aspirin reduces that risk and improves outcomes, so guidelines support initiating therapy unless there are contraindications.

In contrast, having imaging-detected vascular disease without a prior ASCVD event is not as definitive for starting aspirin, because the benefit in primary prevention is uncertain and must be weighed against bleeding risk. Diabetes with low estimated ASCVD risk generally does not justify routine aspirin for primary prevention, given bleeding concerns and the lack of net benefit. Age over 70, in the absence of established ASCVD, also tends to steer away from initiating aspirin for primary prevention due to increased bleeding risk and uncertain net benefit.