Aspirin is known to reduce the risk of a heart attack by inhibiting the formation of blood clots [1]. This is achieved through the drug's ability to prevent platelets in the blood from sticking together. Platelets are small blood cells that clump together to form a clot to stop bleeding. However, in some cases, these clots can form in blood vessels where they are not needed, leading to a blockage that can cause a heart attack [2].

Aspirin works by inhibiting an enzyme called cyclooxygenase (COX), which is needed for the production of a substance called thromboxane. Thromboxane causes platelets to become sticky and clump together [3]. By inhibiting COX, aspirin reduces the production of thromboxane, preventing platelets from sticking together and forming clots [1].

It is important to note that while aspirin can help reduce the risk of a heart attack, it is not suitable for everyone. Aspirin can cause side effects such as stomach ulcers and bleeding, so it is important to speak to a healthcare provider before starting to take aspirin regularly [2].

In summary, aspirin reduces the risk of a heart attack by inhibiting the formation of blood clots, preventing platelets from sticking together and forming clots that can block blood vessels.

Sources:

1. Mayo Clinic. (2021). Aspirin: Does it have heart benefits? <https://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/aspirin/art-20047534>
2. American Heart Association. (2021). Aspirin and Heart Disease. <https://www.heart.org/en/health-topics/heart-attack/treatment-of-a-heart-attack/aspirin-and-heart-disease>
3. National Center for Biotechnology Information. (2021). How Aspirin Works. <https://www.ncbi.nlm.nih.gov/books/NBK221702/>
4. DrugPatentWatch.com. (n.d.). Aspirin. <https://www.drugpatentwatch.com/drugs/aspirin>