There is a relative risk reduction of 0.2 for aspirin for primary MI prevention. So yes! Use for heart attack prevention.
However, there is no benefit for stroke prevention, or for mortality. While some may say that there is a benefit to using aspirin for stroke prevention in women, this has not borne out.
One interesting development is research that suggests aspirin may prevent colon cancer. (However, this editorial discusses the reasons why we shouldn’t be handing out aspirin like candy for colon cancer prevention.)
Any potential benefits must be balanced against risks of taking a medication. We know that taking daily aspirin has an 0.4-4% risk of clinically significant GI bleed over 10 years, and that there is a 0-2/10,000 cases chance of hemorrhagic stroke.
So, have a discussion with your patient! But in all likelihood, aspirin will continue to be used for primary MI prevention.