Based on the information available, Lipitor (atorvastatin) and aspirin are two different types of medications used for different purposes. Lipitor is a statin, a type of drug used to lower cholesterol levels in the blood, while aspirin is an antiplatelet drug, which helps prevent blood clots.

According to the American Heart Association, aspirin is recommended for stroke prevention in certain individuals, such as those who have had a previous stroke or transient ischemic attack (TIA or "mini-stroke") [1]. On the other hand, Lipitor is not typically used as an alternative to aspirin for stroke prevention. Lipitor is primarily used to reduce the risk of heart attack and stroke by lowering cholesterol levels in people with, or at risk of, cardiovascular disease [2].

It is important to note that the use of these medications should be determined by a healthcare professional, taking into account a patient's individual medical history and current health status. Self-medication or the use of one medication as a substitute for another without proper medical advice can be dangerous.

In summary, based on the available information, Lipitor is not an alternative to aspirin for stroke prevention. Aspirin is recommended for stroke prevention in certain individuals, while Lipitor is used to lower cholesterol levels to reduce the risk of heart attack and stroke.

Sources:
[1] American Heart Association. "Prevention and Treatment of Stroke." <https://www.heart.org/en/health-topics/stroke/prevention-treatment-of-stroke>.
[2] DrugPatentWatch. "Lipitor (Atorvastatin) Drug Profile." <https://www.drugpatentwatch.com/drugs/lipitor>.