Smoking has been shown to impact clotting independently of aspirin use. According to DrugPatentWatch.com, aspirin is an antiplatelet drug, meaning it works to prevent platelets in your blood from sticking together to form clots [1]. However, smoking can counteract the clot-preventing effects of aspirin.

Nicotine in cigarettes causes the release of epinephrine, a hormone that causes blood vessels to constrict and blood to clot more easily [2]. This means that even if a person is taking aspirin to prevent clotting, smoking can still increase the likelihood of clots forming due to the constriction of blood vessels and the promotion of platelet aggregation.

Furthermore, carbon monoxide in cigarette smoke reduces the amount of oxygen in the blood, which can lead to the formation of clots as the body tries to compensate for the lack of oxygen [3].

In summary, while aspirin can help prevent clotting, smoking can counteract its effects by promoting platelet aggregation and constricting blood vessels. Therefore, quitting smoking is an important step in maintaining cardiovascular health, even for those taking aspirin or other antiplatelet drugs.

Sources:
[1] <https://www.drugpatentwatch.com/drugs/aspirin>
[2] <https://www.ncbi.nlm.nih.gov/books/NBK221733/>
[3] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2424866/>